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Spring Cloud Vault Config provides client-side support for externalized configuration in a distributed system. With HashiCorp’s Vault you have a central place to manage external secret properties for applications across all environments. Vault can manage static and dynamic secrets such as username/password for remote applications/resources and provide credentials for external services such as MySQL, PostgreSQL, Apache Cassandra, Couchbase, MongoDB, Consul, AWS and more.

1. New & Noteworthy

This section briefly covers items that are new and noteworthy in the latest releases.

1.1. New in Spring Cloud Vault 3.0

  • Migration of PropertySource initialization from Spring Cloud’s Bootstrap Context to Spring Boot’s ConfigData API.

  • Support for the Couchbase Database backend.

  • Configuration of keystore/truststore types through spring.cloud.vault.ssl.key-store-type=…/spring.cloud.vault.ssl.trust-store-type=… including PEM support.

  • Support for ReactiveDiscoveryClient by configuring a ReactiveVaultEndpointProvider.

2. Quick Start

Prerequisites

To get started with Vault and this guide you need a *NIX-like operating systems that provides:

  • wget, openssl and unzip

  • at least Java 8 and a properly configured JAVA_HOME environment variable

This guide explains Vault setup from a Spring Cloud Vault perspective for integration testing. You can find a getting started guide directly on the Vault project site: learn.hashicorp.com/vault

Install Vault

$ wget https://releases.hashicorp.com/vault/${vault_version}/vault_${vault_version}_${platform}.zip
$ unzip vault_${vault_version}_${platform}.zip
These steps can be achieved by downloading and running install_vault.sh.

Create SSL certificates for Vault

Next, you’r required to generate a set of certificates:

  • Root CA

  • Vault Certificate (decrypted key work/ca/private/localhost.decrypted.key.pem and certificate work/ca/certs/localhost.cert.pem)

Make sure to import the Root Certificate into a Java-compliant truststore.

The easiest way to achieve this is by using OpenSSL.

create_certificates.sh creates certificates in work/ca and a JKS truststore work/keystore.jks. If you want to run Spring Cloud Vault using this quickstart guide you need to configure the truststore the spring.cloud.vault.ssl.trust-store property to file:work/keystore.jks.

Start Vault server

Next create a config file along the lines of:

backend "inmem" {
}

listener "tcp" {
  address = "0.0.0.0:8200"
  tls_cert_file = "work/ca/certs/localhost.cert.pem"
  tls_key_file = "work/ca/private/localhost.decrypted.key.pem"
}

disable_mlock = true
You can find an example config file at vault.conf. 
$ vault server -config=vault.conf

Vault is started listening on 0.0.0.0:8200 using the inmem storage and https. Vault is sealed and not initialized when starting up.

If you want to run tests, leave Vault uninitialized. The tests will initialize Vault and create a root token 00000000-0000-0000-0000-000000000000.

If you want to use Vault for your application or give it a try then you need to initialize it first.

$ export VAULT_ADDR="https://localhost:8200"
$ export VAULT_SKIP_VERIFY=true # Don't do this for production
$ vault init

You should see something like:

Key 1: 7149c6a2e16b8833f6eb1e76df03e47f6113a3288b3093faf5033d44f0e70fe701
Key 2: 901c534c7988c18c20435a85213c683bdcf0efcd82e38e2893779f152978c18c02
Key 3: 03ff3948575b1165a20c20ee7c3e6edf04f4cdbe0e82dbff5be49c63f98bc03a03
Key 4: 216ae5cc3ddaf93ceb8e1d15bb9fc3176653f5b738f5f3d1ee00cd7dccbe926e04
Key 5: b2898fc8130929d569c1677ee69dc5f3be57d7c4b494a6062693ce0b1c4d93d805
Initial Root Token: 19aefa97-cccc-bbbb-aaaa-225940e63d76

Vault initialized with 5 keys and a key threshold of 3. Please
securely distribute the above keys. When the Vault is re-sealed,
restarted, or stopped, you must provide at least 3 of these keys
to unseal it again.

Vault does not store the master key. Without at least 3 keys,
your Vault will remain permanently sealed.

Vault will initialize and return a set of unsealing keys and the root token. Pick 3 keys and unseal Vault. Store the Vault token in the VAULT_TOKEN environment variable.

$ vault unseal (Key 1)
$ vault unseal (Key 2)
$ vault unseal (Key 3)
$ export VAULT_TOKEN=(Root token)
# Required to run Spring Cloud Vault tests after manual initialization
$ vault token-create -id="00000000-0000-0000-0000-000000000000" -policy="root"

Spring Cloud Vault accesses different resources. By default, the secret backend is enabled which accesses secret config settings via JSON endpoints.

The HTTP service has resources in the form:

/secret/{application}/{profile}
/secret/{application}
/secret/{defaultContext}/{profile}
/secret/{defaultContext}

where the "application" is injected as the spring.application.name in the SpringApplication (i.e. what is normally "application" in a regular Spring Boot app), "profile" is an active profile (or comma-separated list of properties). Properties retrieved from Vault will be used "as-is" without further prefixing of the property names.

3. Client Side Usage

To use these features in an application, just build it as a Spring Boot application that depends on spring-cloud-vault-config (e.g. see the test cases). Example Maven configuration:

Example 1. pom.xml
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.4.0.RELEASE</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-vault-config</artifactId>
        <version>3.1.0-M3</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

<!-- repositories also needed for snapshots and milestones -->

Then you can create a standard Spring Boot application, like this simple HTTP server:

@SpringBootApplication
@RestController
public class Application {

    @RequestMapping("/")
    public String home() {
        return "Hello World!";
    }

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

When it runs it will pick up the external configuration from the default local Vault server on port 8200 if it is running. To modify the startup behavior you can change the location of the Vault server using application.properties, for example

Example 2. application.yml
spring.cloud.vault:
    host: localhost
    port: 8200
    scheme: https
    uri: https://localhost:8200
    connection-timeout: 5000
    read-timeout: 15000
    config:
spring.config.import: vault://

  • host sets the hostname of the Vault host. The host name will be used for SSL certificate validation

  • port sets the Vault port

  • scheme setting the scheme to http will use plain HTTP. Supported schemes are http and https.

  • uri configure the Vault endpoint with an URI. Takes precedence over host/port/scheme configuration

  • connection-timeout sets the connection timeout in milliseconds

  • read-timeout sets the read timeout in milliseconds

  • spring.config.import mounts Vault as PropertySource using all enabled secret backends (key-value enabled by default)

Enabling further integrations requires additional dependencies and configuration. Depending on how you have set up Vault you might need additional configuration like SSL and authentication.

If the application imports the spring-boot-starter-actuator project, the status of the vault server will be available via the /health endpoint.

The vault health indicator can be enabled or disabled through the property management.health.vault.enabled (default to true).

With Spring Cloud Vault 3.0 and Spring Boot 2.4, the bootstrap context initialization (bootstrap.yml, bootstrap.properties) of property sources was deprecated. Instead, Spring Cloud Vault favors Spring Boot’s Config Data API which allows importing configuration from Vault. With Spring Boot Config Data approach, you need to set the spring.config.import property in order to bind to Vault. You can read more about it in the Config Data Locations section. You can enable the bootstrap context either by setting the configuration property spring.cloud.bootstrap.enabled=true or by including the dependency org.springframework.cloud:spring-cloud-starter-bootstrap.

3.1. Authentication

Vault requires an authentication mechanism to authorize client requests.

Spring Cloud Vault supports multiple authentication mechanisms to authenticate applications with Vault.

For a quickstart, use the root token printed by the Vault initialization.

Example 3. application.yml
spring.cloud.vault:
    token: 19aefa97-cccc-bbbb-aaaa-225940e63d76
spring.config.import: vault://
Consider carefully your security requirements. Static token authentication is fine if you want quickly get started with Vault, but a static token is not protected any further. Any disclosure to unintended parties allows Vault use with the associated token roles.

4. ConfigData API

Spring Boot provides since version 2.4 a ConfigData API that allows the declaration of configuration sources and importing these as property sources.

Spring Cloud Vault uses as of version 3.0 the ConfigData API to mount Vault’s secret backends as property sources. In previous versions, the Bootstrap context was used. The ConfigData API is much more flexible as it allows specifying which configuration systems to import and in which order.

You can enable the deprecated bootstrap context either by setting the configuration property spring.cloud.bootstrap.enabled=true or by including the dependency org.springframework.cloud:spring-cloud-starter-bootstrap.

4.1. ConfigData Locations

You can mount Vault configuration through one or more PropertySource that are materialized from Vault. Spring Cloud Vault supports two config locations:

  • vault:// (default location)

  • vault:///<context-path> (contextual location)

Using the default location mounts property sources for all enabled Secret Backends. Without further configuration, Spring Cloud Vault mounts the key-value backend at /secret/${spring.application.name}. Each activated profile adds another context path following the form /secret/${spring.application.name}/${profile}. Adding further modules to the classpath, such as spring-cloud-config-databases, provides additional secret backend configuration options which get mounted as property sources if enabled.

If you want to control which context paths are mounted from Vault as PropertySource, you can either use a contextual location (vault:///my/context/path) or configure a VaultConfigurer.

Contextual locations are specified and mounted individually. Spring Cloud Vault mounts each location as a unique PropertySource. You can mix the default locations with contextual locations (or other config systems) to control the order of property sources. This approach is useful in particular if you want to disable the default key-value path computation and mount each key-value backend yourself instead.

Example 4. application.yml
spring.config.import: vault://first/context/path, vault://other/path, vault://

Property names within a Spring Environment must be unique to avoid shadowing. If you use the same secret names in different context paths and you want to expose these as individual properties you can distinguish them by adding a prefix query parameter to the location.

Example 5. application.yml
spring.config.import: vault://my/path?prefix=foo., vault://my/other/path?prefix=bar.
secret: ${foo.secret}
other.secret: ${bar.secret}
Prefixes are added as-is to all property names returned by Vault. If you want key names to be separated with a dot between the prefix and key name, make sure to add a trailing dot to the prefix.

4.2. Conditionally enable/disable Vault Configuration

In some cases, it can be required to launch an application without Vault. You can express whether a Vault config location should be optional or mandatory (default) through the location string:

  • optional:vault:// (default location)

  • optional:vault:///<context-path> (contextual location)

Optional locations are skipped during application startup if Vault support was disabled through spring.cloud.vault.enabled=false.

Vault context paths that cannot be found (HTTP Status 404) are skipped regardless of whether the config location is marked optional. Vault Client Fail Fast allows failing on start if a Vault context path cannot be found because of HTTP Status 404.

4.3. Infrastructure Customization

Spring Cloud Vault requires infrastructure classes to interact with Vault. When not using the ConfigData API (meaning that you haven’t specified spring.config.import=vault:// or a contextual Vault path), Spring Cloud Vault defines its beans through VaultAutoConfiguration and VaultReactiveAutoConfiguration. Spring Boot bootstraps the application before a Spring Context is available. Therefore VaultConfigDataLoader registers beans itself to propagate these later on into the application context.

You can customize the infrastructure used by Spring Cloud Vault by registering custom instances using the Bootstrapper API:

InstanceSupplier<RestTemplateBuilder> builderSupplier = ctx -> RestTemplateBuilder
      .builder()
      .requestFactory(ctx.get(ClientFactoryWrapper.class).getClientHttpRequestFactory())
      .defaultHeader("X-Vault-Namespace", "my-namespace");

SpringApplication application = new SpringApplication(MyApplication.class);
application.addBootstrapper(registry -> registry.register(RestTemplateBuilder.class, builderSupplier));

See also Customize which secret backends to expose as PropertySource and the source of VaultConfigDataLoader for customization hooks.

5. Authentication methods

Different organizations have different requirements for security and authentication. Vault reflects that need by shipping multiple authentication methods. Spring Cloud Vault supports token and AppId authentication.

5.1. Token authentication

Tokens are the core method for authentication within Vault. Token authentication requires a static token to be provided using the configuration. As a fallback, the token may also be retrieved from ~/.vault-token which is the default location used by the Vault CLI to cache tokens.

Token authentication is the default authentication method. If a token is disclosed an unintended party gains access to Vault and can access secrets for the intended client.
Example 6. application.yml
spring.cloud.vault:
    authentication: TOKEN
    token: 00000000-0000-0000-0000-000000000000

  • authentication setting this value to TOKEN selects the Token authentication method

  • token sets the static token to use. If missing or empty, then an attempt will be made to retrieve a token from ~/.vault-token.

See also:

5.2. Vault Agent authentication

Vault ships a sidecar utility with Vault Agent since version 0.11.0. Vault Agent implements the functionality of Spring Vault’s SessionManager with its Auto-Auth feature. Applications can reuse cached session credentials by relying on Vault Agent running on localhost. Spring Vault can send requests without the X-Vault-Token header. Disable Spring Vault’s authentication infrastructure to disable client authentication and session management.

Example 7. application.yml
spring.cloud.vault:
    authentication: NONE

  • authentication setting this value to NONE disables ClientAuthentication and SessionManager.

See also: Vault Documentation: Agent

5.3. AppId authentication

Vault supports AppId authentication that consists of two hard to guess tokens. The AppId defaults to spring.application.name that is statically configured. The second token is the UserId which is a part determined by the application, usually related to the runtime environment. IP address, Mac address or a Docker container name are good examples. Spring Cloud Vault Config supports IP address, Mac address and static UserId’s (e.g. supplied via System properties). The IP and Mac address are represented as Hex-encoded SHA256 hash.

IP address-based UserId’s use the local host’s IP address.

Example 8. application.yml using SHA256 IP-Address UserId’s
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: IP_ADDRESS

  • authentication setting this value to APPID selects the AppId authentication method

  • app-id-path sets the path of the AppId mount to use

  • user-id sets the UserId method. Possible values are IP_ADDRESS, MAC_ADDRESS or a class name implementing a custom AppIdUserIdMechanism

The corresponding command to generate the IP address UserId from a command line is:

$ echo -n 192.168.99.1 | sha256sum
Including the line break of echo leads to a different hash value so make sure to include the -n flag.

Mac address-based UserId’s obtain their network device from the localhost-bound device. The configuration also allows specifying a network-interface hint to pick the right device. The value of network-interface is optional and can be either an interface name or interface index (0-based).

Example 9. application.yml using SHA256 Mac-Address UserId’s
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: MAC_ADDRESS
        network-interface: eth0

  • network-interface sets network interface to obtain the physical address

The corresponding command to generate the IP address UserId from a command line is:

$ echo -n 0AFEDE1234AC | sha256sum
The Mac address is specified uppercase and without colons. Including the line break of echo leads to a different hash value so make sure to include the -n flag.

5.3.1. Custom UserId

The UserId generation is an open mechanism. You can set spring.cloud.vault.app-id.user-id to any string and the configured value will be used as static UserId.

A more advanced approach lets you set spring.cloud.vault.app-id.user-id to a classname. This class must be on your classpath and must implement the org.springframework.cloud.vault.AppIdUserIdMechanism interface and the createUserId method. Spring Cloud Vault will obtain the UserId by calling createUserId each time it authenticates using AppId to obtain a token.

Example 10. application.yml
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: com.examlple.MyUserIdMechanism
Example 11. MyUserIdMechanism.java
public class MyUserIdMechanism implements AppIdUserIdMechanism {

  @Override
  public String createUserId() {
    String userId = ...
    return userId;
  }
}

See also: Vault Documentation: Using the App ID auth backend

5.4. AppRole authentication

AppRole is intended for machine authentication, like the deprecated (since Vault 0.6.1) AppId authentication. AppRole authentication consists of two hard to guess (secret) tokens: RoleId and SecretId.

Spring Vault supports various AppRole scenarios (push/pull mode and wrapped).

RoleId and optionally SecretId must be provided by configuration, Spring Vault will not look up these or create a custom SecretId.

Example 12. application.yml with AppRole authentication properties
spring.cloud.vault:
    authentication: APPROLE
    app-role:
        role-id: bde2076b-cccb-3cf0-d57e-bca7b1e83a52

The following scenarios are supported along the required configuration details:

Table 1. Configuration

Method

RoleId

SecretId

RoleName

Token

Provided RoleId/SecretId

Provided

Provided

Provided RoleId without SecretId

Provided

Provided RoleId, Pull SecretId

Provided

Provided

Provided

Provided

Pull RoleId, provided SecretId

Provided

Provided

Provided

Full Pull Mode

Provided

Provided

Wrapped

Provided

Wrapped RoleId, provided SecretId

Provided

Provided

Provided RoleId, wrapped SecretId

Provided

Provided
Table 2. Pull/Push/Wrapped Matrix

RoleId

SecretId

Supported

Provided

Provided

✅

Provided

Pull

✅

Provided

Wrapped

✅

Provided

Absent

✅

Pull

Provided

✅

Pull

Pull

✅

Pull

Wrapped

❌

Pull

Absent

❌

Wrapped

Provided

✅

Wrapped

Pull

❌

Wrapped

Wrapped

✅

Wrapped

Absent

❌
You can use still all combinations of push/pull/wrapped modes by providing a configured AppRoleAuthentication bean within the context. Spring Cloud Vault cannot derive all possible AppRole combinations from the configuration properties.
AppRole authentication is limited to simple pull mode using reactive infrastructure. Full pull mode is not yet supported. Using Spring Cloud Vault with the Spring WebFlux stack enables Vault’s reactive auto-configuration which can be disabled by setting spring.cloud.vault.reactive.enabled=false.
Example 13. application.yml with all AppRole authentication properties
spring.cloud.vault:
    authentication: APPROLE
    app-role:
        role-id: bde2076b-cccb-3cf0-d57e-bca7b1e83a52
        secret-id: 1696536f-1976-73b1-b241-0b4213908d39
        role: my-role
        app-role-path: approle

  • role-id sets the RoleId.

  • secret-id sets the SecretId. SecretId can be omitted if AppRole is configured without requiring SecretId (See bind_secret_id).

  • role: sets the AppRole name for pull mode.

  • app-role-path sets the path of the approle authentication mount to use.

See also: Vault Documentation: Using the AppRole auth backend

5.5. AWS-EC2 authentication

The aws-ec2 auth backend provides a secure introduction mechanism for AWS EC2 instances, allowing automated retrieval of a Vault token. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats AWS as a Trusted Third Party and uses the cryptographically signed dynamic metadata information that uniquely represents each EC2 instance.

Example 14. application.yml using AWS-EC2 Authentication
spring.cloud.vault:
    authentication: AWS_EC2

AWS-EC2 authentication enables nonce by default to follow the Trust On First Use (TOFU) principle. Any unintended party that gains access to the PKCS#7 identity metadata can authenticate against Vault.

During the first login, Spring Cloud Vault generates a nonce that is stored in the auth backend aside the instance Id. Re-authentication requires the same nonce to be sent. Any other party does not have the nonce and can raise an alert in Vault for further investigation.

The nonce is kept in memory and is lost during application restart. You can configure a static nonce with spring.cloud.vault.aws-ec2.nonce.

AWS-EC2 authentication roles are optional and default to the AMI. You can configure the authentication role by setting the spring.cloud.vault.aws-ec2.role property.

Example 15. application.yml with configured role
spring.cloud.vault:
    authentication: AWS_EC2
    aws-ec2:
        role: application-server
Example 16. application.yml with all AWS EC2 authentication properties
spring.cloud.vault:
    authentication: AWS_EC2
    aws-ec2:
        role: application-server
        aws-ec2-path: aws-ec2
        identity-document: http://...
        nonce: my-static-nonce

  • authentication setting this value to AWS_EC2 selects the AWS EC2 authentication method

  • role sets the name of the role against which the login is being attempted.

  • aws-ec2-path sets the path of the AWS EC2 mount to use

  • identity-document sets URL of the PKCS#7 AWS EC2 identity document

  • nonce used for AWS-EC2 authentication. An empty nonce defaults to nonce generation

See also: Vault Documentation: Using the aws auth backend

5.6. AWS-IAM authentication

The aws backend provides a secure authentication mechanism for AWS IAM roles, allowing the automatic authentication with vault based on the current IAM role of the running application. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats AWS as a Trusted Third Party and uses the 4 pieces of information signed by the caller with their IAM credentials to verify that the caller is indeed using that IAM role.

The current IAM role the application is running in is automatically calculated. If you are running your application on AWS ECS then the application will use the IAM role assigned to the ECS task of the running container. If you are running your application naked on top of an EC2 instance then the IAM role used will be the one assigned to the EC2 instance.

When using the AWS-IAM authentication you must create a role in Vault and assign it to your IAM role. An empty role defaults to the friendly name the current IAM role.

Example 17. application.yml with required AWS-IAM Authentication properties
spring.cloud.vault:
    authentication: AWS_IAM
Example 18. application.yml with all AWS-IAM Authentication properties
spring.cloud.vault:
    authentication: AWS_IAM
    aws-iam:
        role: my-dev-role
        aws-path: aws
        server-name: some.server.name
        endpoint-uri: https://sts.eu-central-1.amazonaws.com

  • role sets the name of the role against which the login is being attempted. This should be bound to your IAM role. If one is not supplied then the friendly name of the current IAM user will be used as the vault role.

  • aws-path sets the path of the AWS mount to use

  • server-name sets the value to use for the X-Vault-AWS-IAM-Server-ID header preventing certain types of replay attacks.

  • endpoint-uri sets the value to use for the AWS STS API used for the iam_request_url parameter.

AWS-IAM requires the AWS Java SDK dependency (com.amazonaws:aws-java-sdk-core) as the authentication implementation uses AWS SDK types for credentials and request signing.

See also: Vault Documentation: Using the aws auth backend

5.7. Azure MSI authentication

The azure auth backend provides a secure introduction mechanism for Azure VM instances, allowing automated retrieval of a Vault token. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats Azure as a Trusted Third Party and uses the managed service identity and instance metadata information that can be bound to a VM instance.

Example 19. application.yml with required Azure Authentication properties
spring.cloud.vault:
    authentication: AZURE_MSI
    azure-msi:
        role: my-dev-role
Example 20. application.yml with all Azure Authentication properties
spring.cloud.vault:
    authentication: AZURE_MSI
    azure-msi:
        role: my-dev-role
        azure-path: azure
        metadata-service: http://169.254.169.254/metadata/instance…
        identity-token-service: http://169.254.169.254/metadata/identity…

  • role sets the name of the role against which the login is being attempted.

  • azure-path sets the path of the Azure mount to use

  • metadata-service sets the URI at which to access the instance metadata service

  • identity-token-service sets the URI at which to access the identity token service

Azure MSI authentication obtains environmental details about the virtual machine (subscription Id, resource group, VM name) from the instance metadata service. The Vault server has Resource Id defaults to vault.hashicorp.com. To change this, set spring.cloud.vault.azure-msi.identity-token-service accordingly.

See also:

5.8. TLS certificate authentication

The cert auth backend allows authentication using SSL/TLS client certificates that are either signed by a CA or self-signed.

To enable cert authentication you need to:

  1. Use SSL, see Vault Client SSL configuration

  2. Configure a Java Keystore that contains the client certificate and the private key

  3. Set the spring.cloud.vault.authentication to CERT

Example 21. application.yml
spring.cloud.vault:
    authentication: CERT
    ssl:
        key-store: classpath:keystore.jks
        key-store-password: changeit
        key-store-type: JKS
        cert-auth-path: cert

See also: Vault Documentation: Using the Cert auth backend

5.9. Cubbyhole authentication

Cubbyhole authentication uses Vault primitives to provide a secured authentication workflow. Cubbyhole authentication uses tokens as primary login method. An ephemeral token is used to obtain a second, login VaultToken from Vault’s Cubbyhole secret backend. The login token is usually longer-lived and used to interact with Vault. The login token will be retrieved from a wrapped response stored at /cubbyhole/response.

Creating a wrapped token

Response Wrapping for token creation requires Vault 0.6.0 or higher.
Example 22. Creating and storing tokens
$ vault token-create -wrap-ttl="10m"
Key                            Value
---                            -----
wrapping_token:                397ccb93-ff6c-b17b-9389-380b01ca2645
wrapping_token_ttl:            0h10m0s
wrapping_token_creation_time:  2016-09-18 20:29:48.652957077 +0200 CEST
wrapped_accessor:              46b6aebb-187f-932a-26d7-4f3d86a68319
Example 23. application.yml
spring.cloud.vault:
    authentication: CUBBYHOLE
    token: 397ccb93-ff6c-b17b-9389-380b01ca2645

See also:

5.10. GCP-GCE authentication

The gcp auth backend allows Vault login by using existing GCP (Google Cloud Platform) IAM and GCE credentials.

GCP GCE (Google Compute Engine) authentication creates a signature in the form of a JSON Web Token (JWT) for a service account. A JWT for a Compute Engine instance is obtained from the GCE metadata service using Instance identification. This API creates a JSON Web Token that can be used to confirm the instance identity.

Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats GCP as a Trusted Third Party and uses the cryptographically signed dynamic metadata information that uniquely represents each GCP service account.

Example 24. application.yml with required GCP-GCE Authentication properties
spring.cloud.vault:
    authentication: GCP_GCE
    gcp-gce:
        role: my-dev-role
Example 25. application.yml with all GCP-GCE Authentication properties
spring.cloud.vault:
    authentication: GCP_GCE
    gcp-gce:
        gcp-path: gcp
        role: my-dev-role
        service-account: [email protected]

  • role sets the name of the role against which the login is being attempted.

  • gcp-path sets the path of the GCP mount to use

  • service-account allows overriding the service account Id to a specific value. Defaults to the default service account.

See also:

5.11. GCP-IAM authentication

The gcp auth backend allows Vault login by using existing GCP (Google Cloud Platform) IAM and GCE credentials.

GCP IAM authentication creates a signature in the form of a JSON Web Token (JWT) for a service account. A JWT for a service account is obtained by calling GCP IAM’s projects.serviceAccounts.signJwt API. The caller authenticates against GCP IAM and proves thereby its identity. This Vault backend treats GCP as a Trusted Third Party.

IAM credentials can be obtained from either the runtime environment , specifically the GOOGLE_APPLICATION_CREDENTIALS environment variable, the Google Compute metadata service, or supplied externally as e.g. JSON or base64 encoded. JSON is the preferred form as it carries the project id and service account identifier required for calling projects.serviceAccounts.signJwt.

Example 26. application.yml with required GCP-IAM Authentication properties
spring.cloud.vault:
    authentication: GCP_IAM
    gcp-iam:
        role: my-dev-role
Example 27. application.yml with all GCP-IAM Authentication properties
spring.cloud.vault:
    authentication: GCP_IAM
    gcp-iam:
        credentials:
            location: classpath:credentials.json
            encoded-key: e+KApn0=
        gcp-path: gcp
        jwt-validity: 15m
        project-id: my-project-id
        role: my-dev-role
        service-account-id: [email protected]

  • role sets the name of the role against which the login is being attempted.

  • credentials.location path to the credentials resource that contains Google credentials in JSON format.

  • credentials.encoded-key the base64 encoded contents of an OAuth2 account private key in the JSON format.

  • gcp-path sets the path of the GCP mount to use

  • jwt-validity configures the JWT token validity. Defaults to 15 minutes.

  • project-id allows overriding the project Id to a specific value. Defaults to the project Id from the obtained credential.

  • service-account allows overriding the service account Id to a specific value. Defaults to the service account from the obtained credential.

GCP IAM authentication requires the Google Cloud Java SDK dependency (com.google.apis:google-api-services-iam and com.google.auth:google-auth-library-oauth2-http) as the authentication implementation uses Google APIs for credentials and JWT signing.

Google credentials require an OAuth 2 token maintaining the token lifecycle. All API is synchronous therefore, GcpIamAuthentication does not support AuthenticationSteps which is required for reactive usage.

See also:

5.12. Kubernetes authentication

Kubernetes authentication mechanism (since Vault 0.8.3) allows to authenticate with Vault using a Kubernetes Service Account Token. The authentication is role based and the role is bound to a service account name and a namespace.

A file containing a JWT token for a pod’s service account is automatically mounted at /var/run/secrets/kubernetes.io/serviceaccount/token.

Example 28. application.yml with all Kubernetes authentication properties
spring.cloud.vault:
    authentication: KUBERNETES
    kubernetes:
        role: my-dev-role
        kubernetes-path: kubernetes
        service-account-token-file: /var/run/secrets/kubernetes.io/serviceaccount/token

  • role sets the Role.

  • kubernetes-path sets the path of the Kubernetes mount to use.

  • service-account-token-file sets the location of the file containing the Kubernetes Service Account Token. Defaults to /var/run/secrets/kubernetes.io/serviceaccount/token.

See also:

5.13. Pivotal CloudFoundry authentication

The pcf auth backend provides a secure introduction mechanism for applications running within Pivotal’s CloudFoundry instances allowing automated retrieval of a Vault token. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.) as identity provisioning is handled by PCF itself. Instead, it treats PCF as a Trusted Third Party and uses the managed instance identity.

Example 29. application.yml with required PCF Authentication properties
spring.cloud.vault:
    authentication: PCF
    pcf:
        role: my-dev-role
Example 30. application.yml with all PCF Authentication properties
spring.cloud.vault:
    authentication: PCF
    pcf:
        role: my-dev-role
        pcf-path: path
        instance-certificate: /etc/cf-instance-credentials/instance.crt
        instance-key: /etc/cf-instance-credentials/instance.key

  • role sets the name of the role against which the login is being attempted.

  • pcf-path sets the path of the PCF mount to use.

  • instance-certificate sets the path to the PCF instance identity certificate. Defaults to ${CF_INSTANCE_CERT} env variable.

  • instance-key sets the path to the PCF instance identity key. Defaults to ${CF_INSTANCE_KEY} env variable.

PCF authentication requires BouncyCastle (bcpkix-jdk15on) to be on the classpath for RSA PSS signing.

See also: Vault Documentation: Using the pcf auth backend

6. ACL Requirements

This section explains which paths are accessed by Spring Vault so you can derive your policy declarations from the required capabilities.

Capability Associated HTTP verbs

create

POST/PUT

read

GET

update

POST/PUT

delete

DELETE

list

LIST (GET)

See also www.vaultproject.io/guides/identity/policies.

6.1. Authentication

Login: POST auth/$authMethod/login

6.2. KeyValue Mount Discovery

GET sys/internal/ui/mounts/$mountPath

6.3. SecretLeaseContainer

SecretLeaseContainer uses different paths depending on the configured lease endpoint.

LeaseEndpoints.Legacy

  • Revocation: PUT sys/revoke

  • Renewal: PUT sys/renew

LeaseEndpoints.Leases (SysLeases)

  • Revocation: PUT sys/leases/revoke

  • Renewal: PUT sys/leases/renew

6.4. Session Management

  • Token lookup: GET auth/token/lookup-self

  • Renewal: POST auth/token/renew-self

  • Revoke: POST auth/token/revoke-self

7. Secret Backends

7.1. Key-Value Backend

Spring Cloud Vault supports both Key-Value secret backends, the versioned (v2) and unversioned (v1). The key-value backend allows storage of arbitrary values as key-value store. A single context can store one or many key-value tuples. Contexts can be organized hierarchically. Spring Cloud Vault determines itself whether a secret is using versioning and maps the path to its appropriate URL. Spring Cloud Vault allows using the Application name, and a default context name (application) in combination with active profiles.

/secret/{application}/{profile}
/secret/{application}
/secret/{default-context}/{profile}
/secret/{default-context}

The application name is determined by the properties:

  • spring.cloud.vault.kv.application-name

  • spring.cloud.vault.application-name

  • spring.application.name

The profiles are determined by the properties:

  • spring.cloud.vault.kv.profiles

  • spring.profiles.active

Secrets can be obtained from other contexts within the key-value backend by adding their paths to the application name, separated by commas. For example, given the application name usefulapp,mysql1,projectx/aws, each of these folders will be used:

  • /secret/usefulapp

  • /secret/mysql1

  • /secret/projectx/aws

Spring Cloud Vault adds all active profiles to the list of possible context paths. No active profiles will skip accessing contexts with a profile name.

Properties are exposed like they are stored (i.e. without additional prefixes).

Spring Cloud Vault adds the data/ context between the mount path and the actual context path depending on whether the mount uses the versioned key-value backend. 
spring.cloud.vault:
    kv:
        enabled: true
        backend: secret
        profile-separator: '/'
        default-context: application
        application-name: my-app
        profiles: local, cloud

  • enabled setting this value to false disables the secret backend config usage

  • backend sets the path of the secret mount to use

  • default-context sets the context name used by all applications

  • application-name overrides the application name for use in the key-value backend

  • profiles overrides the active profiles for use in the key-value backend

  • profile-separator separates the profile name from the context in property sources with profiles

The key-value secret backend can be operated in versioned (v2) and non-versioned (v1) modes.

See also:

7.2. Consul

Spring Cloud Vault can obtain credentials for HashiCorp Consul. The Consul integration requires the spring-cloud-vault-config-consul dependency.

Example 31. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-consul</artifactId>
        <version>3.1.0-M3</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.consul.enabled=true (default false) and providing the role name with spring.cloud.vault.consul.role=….

The obtained token is stored in spring.cloud.consul.token so using Spring Cloud Consul can pick up the generated credentials without further configuration. You can configure the property name by setting spring.cloud.vault.consul.token-property.

spring.cloud.vault:
    consul:
        enabled: true
        role: readonly
        backend: consul
        token-property: spring.cloud.consul.token

  • enabled setting this value to true enables the Consul backend config usage

  • role sets the role name of the Consul role definition

  • backend sets the path of the Consul mount to use

  • token-property sets the property name in which the Consul ACL token is stored

See also: Vault Documentation: Setting up Consul with Vault

7.3. RabbitMQ

Spring Cloud Vault can obtain credentials for RabbitMQ.

The RabbitMQ integration requires the spring-cloud-vault-config-rabbitmq dependency.

Example 32. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-rabbitmq</artifactId>
        <version>3.1.0-M3</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.rabbitmq.enabled=true (default false) and providing the role name with spring.cloud.vault.rabbitmq.role=….

Username and password are stored in spring.rabbitmq.username and spring.rabbitmq.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.rabbitmq.username-property and spring.cloud.vault.rabbitmq.password-property.

spring.cloud.vault:
    rabbitmq:
        enabled: true
        role: readonly
        backend: rabbitmq
        username-property: spring.rabbitmq.username
        password-property: spring.rabbitmq.password

  • enabled setting this value to true enables the RabbitMQ backend config usage

  • role sets the role name of the RabbitMQ role definition

  • backend sets the path of the RabbitMQ mount to use

  • username-property sets the property name in which the RabbitMQ username is stored

  • password-property sets the property name in which the RabbitMQ password is stored

See also: Vault Documentation: Setting up RabbitMQ with Vault

7.4. AWS

Spring Cloud Vault can obtain credentials for AWS.

The AWS integration requires the spring-cloud-vault-config-aws dependency.

Example 33. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-aws</artifactId>
        <version>3.1.0-M3</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.aws=true (default false) and providing the role name with spring.cloud.vault.aws.role=….

Supported AWS credential Types:

  • iam_user (Defaults)

  • assumed_role (STS)

  • federation_token (STS)

The access key and secret key are stored in cloud.aws.credentials.accessKey and cloud.aws.credentials.secretKey. So using Spring Cloud AWS will pick up the generated credentials without further configuration.

You can configure the property names by setting spring.cloud.vault.aws.access-key-property and spring.cloud.vault.aws.secret-key-property.

For STS security token, you can configure the property name by setting spring.cloud.vault.aws.session-token-key-property. The security token is stored under cloud.aws.credentials.sessionToken (defaults).

Example: iam_user

spring.cloud.vault:
    aws:
        enabled: true
        role: readonly
        backend: aws
        access-key-property: cloud.aws.credentials.accessKey
        secret-key-property: cloud.aws.credentials.secretKey

Example: assumed_role (STS)

spring.cloud.vault:
    aws:
        enabled: true
        role: sts-vault-role
        backend: aws
        credential-type: assumed_role
        access-key-property: cloud.aws.credentials.accessKey
        secret-key-property: cloud.aws.credentials.secretKey
        session-token-key-property: cloud.aws.credentials.sessionToken
        ttl: 3600s
        role-arn: arn:aws:iam::${AWS_ACCOUNT}:role/sts-app-role

  • enabled setting this value to true enables the AWS backend config usage

  • role sets the role name of the AWS role definition

  • backend sets the path of the AWS mount to use

  • access-key-property sets the property name in which the AWS access key is stored

  • secret-key-property sets the property name in which the AWS secret key is stored

  • session-token-key-property sets the property name in which the AWS STS security token is stored.

  • credential-type sets the aws credential type to use for this backend. Defaults to iam_user

  • ttl sets the ttl for the STS token when using assumed_role or federation_token. Defaults to the ttl specified by the vault role. Min/Max values are also limited to what AWS would support for STS.

  • role-arn sets the IAM role to assume if more than one are configured for the vault role when using assumed_role.

See also: Vault Documentation: Setting up AWS with Vault

8. Database backends

Vault supports several database secret backends to generate database credentials dynamically based on configured roles. This means services that need to access a database no longer need to configure credentials: they can request them from Vault, and use Vault’s leasing mechanism to more easily roll keys.

Spring Cloud Vault integrates with these backends:

Using a database secret backend requires to enable the backend in the configuration and the spring-cloud-vault-config-databases dependency.

Vault ships since 0.7.1 with a dedicated database secret backend that allows database integration via plugins. You can use that specific backend by using the generic database backend. Make sure to specify the appropriate backend path, e.g. spring.cloud.vault.mysql.role.backend=database.

Example 34. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-databases</artifactId>
        <version>3.1.0-M3</version>
    </dependency>
</dependencies>
Enabling multiple JDBC-compliant databases will generate credentials and store them by default in the same property keys hence property names for JDBC secrets need to be configured separately.

8.1. Database

Spring Cloud Vault can obtain credentials for any database listed at www.vaultproject.io/api/secret/databases/index.html. The integration can be enabled by setting spring.cloud.vault.database.enabled=true (default false) and providing the role name with spring.cloud.vault.database.role=….

While the database backend is a generic one, spring.cloud.vault.database specifically targets JDBC databases. Username and password are available from spring.datasource.username and spring.datasource.password properties so using Spring Boot will pick up the generated credentials for your DataSource without further configuration. You can configure the property names by setting spring.cloud.vault.database.username-property and spring.cloud.vault.database.password-property.

spring.cloud.vault:
    database:
        enabled: true
        role: readonly
        backend: database
        username-property: spring.datasource.username
        password-property: spring.datasource.password

  • enabled setting this value to true enables the Database backend config usage

  • role sets the role name of the Database role definition

  • backend sets the path of the Database mount to use

  • username-property sets the property name in which the Database username is stored

  • password-property sets the property name in which the Database password is stored

See also: Vault Documentation: Database Secrets backend

Spring Cloud Vault does not support getting new credentials and configuring your DataSource with them when the maximum lease time has been reached. That is, if max_ttl of the Database role in Vault is set to 24h that means that 24 hours after your application has started it can no longer authenticate with the database.

8.2. Apache Cassandra

The cassandra backend has been deprecated in Vault 0.7.1 and it is recommended to use the database backend and mount it as cassandra.

Spring Cloud Vault can obtain credentials for Apache Cassandra. The integration can be enabled by setting spring.cloud.vault.cassandra.enabled=true (default false) and providing the role name with spring.cloud.vault.cassandra.role=….

Username and password are available from spring.data.cassandra.username and spring.data.cassandra.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.cassandra.username-property and spring.cloud.vault.cassandra.password-property.

spring.cloud.vault:
    cassandra:
        enabled: true
        role: readonly
        backend: cassandra
        username-property: spring.data.cassandra.username
        password-property: spring.data.cassandra.password

  • enabled setting this value to true enables the Cassandra backend config usage

  • role sets the role name of the Cassandra role definition

  • backend sets the path of the Cassandra mount to use

  • username-property sets the property name in which the Cassandra username is stored

  • password-property sets the property name in which the Cassandra password is stored

See also: Vault Documentation: Setting up Apache Cassandra with Vault

8.3. Couchbase Database

Spring Cloud Vault can obtain credentials for Couchbase. The integration can be enabled by setting spring.cloud.vault.couchbase.enabled=true (default false) and providing the role name with spring.cloud.vault.couchbase.role=….

Username and password are available from spring.couchbase.username and spring.couchbase.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.couchbase.username-property and spring.cloud.vault.couchbase.password-property.

spring.cloud.vault:
    couchbase:
        enabled: true
        role: readonly
        backend: database
        username-property: spring.couchbase.username
        password-property: spring.couchbase.password

  • enabled setting this value to true enables the Couchbase backend config usage

  • role sets the role name of the Couchbase role definition

  • backend sets the path of the Couchbase mount to use

  • username-property sets the property name in which the Couchbase username is stored

  • password-property sets the property name in which the Couchbase password is stored

See also: Couchbase Database Plugin Documentation

8.4. Elasticsearch

Spring Cloud Vault can obtain since version 3.0 credentials for Elasticsearch. The integration can be enabled by setting spring.cloud.vault.elasticsearch.enabled=true (default false) and providing the role name with spring.cloud.vault.elasticsearch.role=….

Username and password are available from spring.elasticsearch.rest.username and spring.elasticsearch.rest.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.elasticsearch.username-property and spring.cloud.vault.elasticsearch.password-property.

spring.cloud.vault:
    elasticsearch:
        enabled: true
        role: readonly
        backend: mongodb
        username-property: spring.elasticsearch.rest.username
        password-property: spring.elasticsearch.rest.password

  • enabled setting this value to true enables the Elasticsearch database backend config usage

  • role sets the role name of the Elasticsearch role definition

  • backend sets the path of the Elasticsearch mount to use

  • username-property sets the property name in which the Elasticsearch username is stored

  • password-property sets the property name in which the Elasticsearch password is stored

See also: Vault Documentation: Setting up Elasticsearch with Vault

8.5. MongoDB

The mongodb backend has been deprecated in Vault 0.7.1 and it is recommended to use the database backend and mount it as mongodb.

Spring Cloud Vault can obtain credentials for MongoDB. The integration can be enabled by setting spring.cloud.vault.mongodb.enabled=true (default false) and providing the role name with spring.cloud.vault.mongodb.role=….

Username and password are stored in spring.data.mongodb.username and spring.data.mongodb.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.mongodb.username-property and spring.cloud.vault.mongodb.password-property.

spring.cloud.vault:
    mongodb:
        enabled: true
        role: readonly
        backend: mongodb
        username-property: spring.data.mongodb.username
        password-property: spring.data.mongodb.password

  • enabled setting this value to true enables the MongodB backend config usage

  • role sets the role name of the MongoDB role definition

  • backend sets the path of the MongoDB mount to use

  • username-property sets the property name in which the MongoDB username is stored

  • password-property sets the property name in which the MongoDB password is stored

See also: Vault Documentation: Setting up MongoDB with Vault

8.6. MySQL

The mysql backend has been deprecated in Vault 0.7.1 and it is recommended to use the database backend and mount it as mysql. Configuration for spring.cloud.vault.mysql will be removed in a future version.

Spring Cloud Vault can obtain credentials for MySQL. The integration can be enabled by setting spring.cloud.vault.mysql.enabled=true (default false) and providing the role name with spring.cloud.vault.mysql.role=….

Username and password are available from spring.datasource.username and spring.datasource.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.mysql.username-property and spring.cloud.vault.mysql.password-property.

spring.cloud.vault:
    mysql:
        enabled: true
        role: readonly
        backend: mysql
        username-property: spring.datasource.username
        password-property: spring.datasource.password

  • enabled setting this value to true enables the MySQL backend config usage

  • role sets the role name of the MySQL role definition

  • backend sets the path of the MySQL mount to use

  • username-property sets the property name in which the MySQL username is stored

  • password-property sets the property name in which the MySQL password is stored

See also: Vault Documentation: Setting up MySQL with Vault

8.7. PostgreSQL

The postgresql backend has been deprecated in Vault 0.7.1 and it is recommended to use the database backend and mount it as postgresql. Configuration for spring.cloud.vault.postgresql will be removed in a future version.

Spring Cloud Vault can obtain credentials for PostgreSQL. The integration can be enabled by setting spring.cloud.vault.postgresql.enabled=true (default false) and providing the role name with spring.cloud.vault.postgresql.role=….

Username and password are available from spring.datasource.username and spring.datasource.password properties so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.postgresql.username-property and spring.cloud.vault.postgresql.password-property.

spring.cloud.vault:
    postgresql:
        enabled: true
        role: readonly
        backend: postgresql
        username-property: spring.datasource.username
        password-property: spring.datasource.password

  • enabled setting this value to true enables the PostgreSQL backend config usage

  • role sets the role name of the PostgreSQL role definition

  • backend sets the path of the PostgreSQL mount to use

  • username-property sets the property name in which the PostgreSQL username is stored

  • password-property sets the property name in which the PostgreSQL password is stored

See also: Vault Documentation: Setting up PostgreSQL with Vault

9. Customize which secret backends to expose as PropertySource

Spring Cloud Vault uses property-based configuration to create PropertySources for key-value and discovered secret backends.

Discovered backends provide VaultSecretBackendDescriptor beans to describe the configuration state to use secret backend as PropertySource. A SecretBackendMetadataFactory is required to create a SecretBackendMetadata object which contains path, name and property transformation configuration.

SecretBackendMetadata is used to back a particular PropertySource.

You can register a VaultConfigurer for customization. Default key-value and discovered backend registration is disabled if you provide a VaultConfigurer. You can however enable default registration with SecretBackendConfigurer.registerDefaultKeyValueSecretBackends() and SecretBackendConfigurer.registerDefaultDiscoveredSecretBackends().

public class CustomizationBean implements VaultConfigurer {

    @Override
    public void addSecretBackends(SecretBackendConfigurer configurer) {

        configurer.add("secret/my-application");

        configurer.registerDefaultKeyValueSecretBackends(false);
        configurer.registerDefaultDiscoveredSecretBackends(true);
    }
}
SpringApplication application = new SpringApplication(MyApplication.class);
application.addBootstrapper(VaultBootstrapper.fromConfigurer(new CustomizationBean()));

10. Custom Secret Backend Implementations

Spring Cloud Vault ships with secret backend support for the most common backend integrations. You can integrate with any kind of backend by providing an implementation that describes how to obtain data from the backend you want to use and how to surface data provided by that backend by providing a PropertyTransformer.

Adding a custom implementation for a backend requires implementation of two interfaces:

  • org.springframework.cloud.vault.config.VaultSecretBackendDescriptor

  • org.springframework.cloud.vault.config.SecretBackendMetadataFactory

VaultSecretBackendDescriptor is typically an object that holds configuration data, such as VaultDatabaseProperties. Spring Cloud Vault requires that your type is annotated with @ConfigurationProperties to materialize the class from the configuration.

SecretBackendMetadataFactory accepts VaultSecretBackendDescriptor to create the actual SecretBackendMetadata object which holds the context path within your Vault server, any path variables required to resolve parametrized context paths and PropertyTransformer.

Both, VaultSecretBackendDescriptor and SecretBackendMetadataFactory types must be registered in spring.factories which is an extension mechanism provided by Spring, similar to Java’s ServiceLoader.

11. Service Registry Configuration

You can use a DiscoveryClient (such as from Spring Cloud Consul) to locate a Vault server by setting spring.cloud.vault.discovery.enabled=true (default false). The net result of that is that your apps need a application.yml (or an environment variable) with the appropriate discovery configuration. The benefit is that the Vault can change its co-ordinates, as long as the discovery service is a fixed point. The default service id is vault but you can change that on the client with spring.cloud.vault.discovery.serviceId.

The discovery client implementations all support some kind of metadata map (e.g. for Eureka we have eureka.instance.metadataMap). Some additional properties of the service may need to be configured in its service registration metadata so that clients can connect correctly. Service registries that do not provide details about transport layer security need to provide a scheme metadata entry to be set either to https or http. If no scheme is configured and the service is not exposed as secure service, then configuration defaults to spring.cloud.vault.scheme which is https when it’s not set.

spring.cloud.vault.discovery:
    enabled: true
    service-id: my-vault-service

12. Vault Client Fail Fast

In some cases, it may be desirable to fail startup of a service if it cannot connect to the Vault Server. If this is the desired behavior, set the bootstrap configuration property spring.cloud.vault.fail-fast=true and the client will halt with an Exception.

spring.cloud.vault:
    fail-fast: true

13. Vault Enterprise Namespace Support

Vault Enterprise allows using namespaces to isolate multiple Vaults on a single Vault server. Configuring a namespace by setting spring.cloud.vault.namespace=… enables the namespace header X-Vault-Namespace on every outgoing HTTP request when using the Vault RestTemplate or WebClient.

Please note that this feature is not supported by Vault Community edition and has no effect on Vault operations.

spring.cloud.vault:
    namespace: my-namespace

See also: Vault Enterprise: Namespaces

14. Vault Client SSL configuration

SSL can be configured declaratively by setting various properties. You can set either javax.net.ssl.trustStore to configure JVM-wide SSL settings or spring.cloud.vault.ssl.trust-store to set SSL settings only for Spring Cloud Vault Config.

spring.cloud.vault:
    ssl:
        trust-store: classpath:keystore.jks
        trust-store-password: changeit
        trust-store-type: JKS
        enabled-protocols: TLSv1.2,TLSv1.3
        enabled-cipher-suites: TLS_AES_128_GCM_SHA256

  • trust-store sets the resource for the trust-store. SSL-secured Vault communication will validate the Vault SSL certificate with the specified trust-store.

  • trust-store-password sets the trust-store password

  • trust-store-type sets the trust-store type. Supported values are all supported KeyStore types including PEM.

  • enabled-protocols sets the list of enabled SSL/TLS protocols (since 3.0.2).

  • enabled-cipher-suites sets the list of enabled SSL/TLS cipher suites (since 3.0.2).

Please note that configuring spring.cloud.vault.ssl.* can be only applied when either Apache Http Components or the OkHttp client is on your class-path.

15. Lease lifecycle management (renewal and revocation)

With every secret, Vault creates a lease: metadata containing information such as a time duration, renewability, and more.

Vault promises that the data will be valid for the given duration, or Time To Live (TTL). Once the lease is expired, Vault can revoke the data, and the consumer of the secret can no longer be certain that it is valid.

Spring Cloud Vault maintains a lease lifecycle beyond the creation of login tokens and secrets. That said, login tokens and secrets associated with a lease are scheduled for renewal just before the lease expires until terminal expiry. Application shutdown revokes obtained login tokens and renewable leases.

Secret service and database backends (such as MongoDB or MySQL) usually generate a renewable lease so generated credentials will be disabled on application shutdown.

Static tokens are not renewed or revoked.

Lease renewal and revocation is enabled by default and can be disabled by setting spring.cloud.vault.config.lifecycle.enabled to false. This is not recommended as leases can expire and Spring Cloud Vault cannot longer access Vault or services using generated credentials and valid credentials remain active after application shutdown.

spring.cloud.vault:
    config.lifecycle:
        enabled: true
        min-renewal: 10s
        expiry-threshold: 1m
        lease-endpoints: Legacy

  • enabled controls whether leases associated with secrets are considered to be renewed and expired secrets are rotated. Enabled by default.

  • min-renewal sets the duration that is at least required before renewing a lease. This setting prevents renewals from happening too often.

  • expiry-threshold sets the expiry threshold. A lease is renewed the configured period of time before it expires.

  • lease-endpoints sets the endpoints for renew and revoke. Legacy for vault versions before 0.8 and SysLeases for later.

See also: Vault Documentation: Lease, Renew, and Revoke

16. Session token lifecycle management (renewal, re-login and revocation)

A Vault session token (also referred to as LoginToken) is quite similar to a lease as it has a TTL, max TTL, and may expire. Once a login token expires, it cannot be used anymore to interact with Vault. Therefore, Spring Vault ships with a SessionManager API for imperative and reactive use.

Spring Cloud Vault maintains the session token lifecycle by default. Session tokens are obtained lazily so the actual login is deferred until the first session-bound use of Vault. Once Spring Cloud Vault obtains a session token, it retains it until expiry. The next time a session-bound activity is used, Spring Cloud Vault re-logins into Vault and obtains a new session token. On application shut down, Spring Cloud Vault revokes the token if it was still active to terminate the session.

Session lifecycle is enabled by default and can be disabled by setting spring.cloud.vault.session.lifecycle.enabled to false. Disabling is not recommended as session tokens can expire and Spring Cloud Vault cannot longer access Vault.

spring.cloud.vault:
    session.lifecycle:
        enabled: true
        refresh-before-expiry: 10s
        expiry-threshold: 20s

  • enabled controls whether session lifecycle management is enabled to renew session tokens. Enabled by default.

  • refresh-before-expiry controls the point in time when the session token gets renewed. The refresh time is calculated by subtracting refresh-before-expiry from the token expiry time. Defaults to 5 seconds.

  • expiry-threshold sets the expiry threshold. The threshold represents a minimum TTL duration to consider a session token as valid. Tokens with a shorter TTL are considered expired and are not used anymore. Should be greater than refresh-before-expiry to prevent token expiry. Defaults to 7 seconds.

See also: Vault Documentation: Token Renewal

Appendix A: Common application properties

Various properties can be specified inside your application.properties file, inside your application.yml file, or as command line switches. This appendix provides a list of common Spring Cloud Vault properties and references to the underlying classes that consume them.

Property contributions can come from additional jar files on your classpath, so you should not consider this an exhaustive list. Also, you can define your own properties.
Name Default Description

spring.cloud.vault.app-id.app-id-path

app-id

Mount path of the AppId authentication backend.

spring.cloud.vault.app-id.network-interface

Network interface hint for the "MAC_ADDRESS" UserId mechanism.

spring.cloud.vault.app-id.user-id

MAC_ADDRESS

UserId mechanism. Can be either "MAC_ADDRESS", "IP_ADDRESS", a string or a class name.

spring.cloud.vault.app-role.app-role-path

approle

Mount path of the AppRole authentication backend.

spring.cloud.vault.app-role.role

Name of the role, optional, used for pull-mode.

spring.cloud.vault.app-role.role-id

The RoleId.

spring.cloud.vault.app-role.secret-id

The SecretId.

spring.cloud.vault.application-name

application

Application name for AppId authentication.

spring.cloud.vault.authentication

spring.cloud.vault.aws-ec2.aws-ec2-path

aws-ec2

Mount path of the AWS-EC2 authentication backend.

spring.cloud.vault.aws-ec2.identity-document

169.254.169.254/latest/dynamic/instance-identity/pkcs7

URL of the AWS-EC2 PKCS7 identity document.

spring.cloud.vault.aws-ec2.nonce

Nonce used for AWS-EC2 authentication. An empty nonce defaults to nonce generation.

spring.cloud.vault.aws-ec2.role

Name of the role, optional.

spring.cloud.vault.aws-iam.aws-path

aws

Mount path of the AWS authentication backend.

spring.cloud.vault.aws-iam.endpoint-uri

STS server URI. @since 2.2

spring.cloud.vault.aws-iam.role

Name of the role, optional. Defaults to the friendly IAM name if not set.

spring.cloud.vault.aws-iam.server-name

Name of the server used to set {@code X-Vault-AWS-IAM-Server-ID} header in the headers of login requests.

spring.cloud.vault.aws.access-key-property

cloud.aws.credentials.accessKey

Target property for the obtained access key.

spring.cloud.vault.aws.backend

aws

aws backend path.

spring.cloud.vault.aws.credential-type

aws credential type

spring.cloud.vault.aws.enabled

false

Enable aws backend usage.

spring.cloud.vault.aws.role

Role name for credentials.

spring.cloud.vault.aws.role-arn

Role arn for assumed_role in case we have multiple roles associated with the vault role. @since 3.0.2

spring.cloud.vault.aws.secret-key-property

cloud.aws.credentials.secretKey

Target property for the obtained secret key.

spring.cloud.vault.aws.session-token-key-property

cloud.aws.credentials.sessionToken

Target property for the obtained secret key.

spring.cloud.vault.aws.ttl

0

TTL for sts tokens. Defaults to whatever the vault Role may have for Max. Also limited to what AWS supports to be the max for STS. @since 3.0.2

spring.cloud.vault.azure-msi.azure-path

azure

Mount path of the Azure MSI authentication backend.

spring.cloud.vault.azure-msi.identity-token-service

Identity token service URI. @since 3.0

spring.cloud.vault.azure-msi.metadata-service

Instance metadata service URI. @since 3.0

spring.cloud.vault.azure-msi.role

Name of the role.

spring.cloud.vault.cassandra.backend

cassandra

Cassandra backend path.

spring.cloud.vault.cassandra.enabled

false

Enable cassandra backend usage.

spring.cloud.vault.cassandra.password-property

spring.data.cassandra.password

Target property for the obtained password.

spring.cloud.vault.cassandra.role

Role name for credentials.

spring.cloud.vault.cassandra.static-role

false

Enable static role usage. @since 2.2

spring.cloud.vault.cassandra.username-property

spring.data.cassandra.username

Target property for the obtained username.

spring.cloud.vault.config.lifecycle.enabled

true

Enable lifecycle management.

spring.cloud.vault.config.lifecycle.expiry-threshold

The expiry threshold. {@link Lease} is renewed the given {@link Duration} before it expires. @since 2.2

spring.cloud.vault.config.lifecycle.lease-endpoints

Set the {@link LeaseEndpoints} to delegate renewal/revocation calls to. {@link LeaseEndpoints} encapsulates differences between Vault versions that affect the location of renewal/revocation endpoints. Can be {@link LeaseEndpoints#SysLeases} for version 0.8 or above of Vault or {@link LeaseEndpoints#Legacy} for older versions (the default). @since 2.2

spring.cloud.vault.config.lifecycle.min-renewal

The time period that is at least required before renewing a lease. @since 2.2

spring.cloud.vault.config.order

0

Used to set a {@link org.springframework.core.env.PropertySource} priority. This is useful to use Vault as an override on other property sources. @see org.springframework.core.PriorityOrdered

spring.cloud.vault.connection-timeout

5000

Connection timeout.

spring.cloud.vault.consul.backend

consul

Consul backend path.

spring.cloud.vault.consul.enabled

false

Enable consul backend usage.

spring.cloud.vault.consul.role

Role name for credentials.

spring.cloud.vault.consul.token-property

spring.cloud.consul.token

Target property for the obtained token.

spring.cloud.vault.couchbase.backend

database

Couchbase backend path.

spring.cloud.vault.couchbase.enabled

false

Enable couchbase backend usage.

spring.cloud.vault.couchbase.password-property

spring.couchbase.password

Target property for the obtained password.

spring.cloud.vault.couchbase.role

Role name for credentials.

spring.cloud.vault.couchbase.static-role

false

Enable static role usage.

spring.cloud.vault.couchbase.username-property

spring.couchbase.username

Target property for the obtained username.

spring.cloud.vault.database.backend

database

Database backend path.

spring.cloud.vault.database.enabled

false

Enable database backend usage.

spring.cloud.vault.database.password-property

spring.datasource.password

Target property for the obtained password.

spring.cloud.vault.database.role

Role name for credentials.

spring.cloud.vault.database.static-role

false

Enable static role usage.

spring.cloud.vault.database.username-property

spring.datasource.username

Target property for the obtained username.

spring.cloud.vault.discovery.enabled

false

Flag to indicate that Vault server discovery is enabled (vault server URL will be looked up via discovery).

spring.cloud.vault.discovery.service-id

vault

Service id to locate Vault.

spring.cloud.vault.elasticsearch.backend

database

Database backend path.

spring.cloud.vault.elasticsearch.enabled

false

Enable elasticsearch backend usage.

spring.cloud.vault.elasticsearch.password-property

spring.elasticsearch.rest.password

Target property for the obtained password.

spring.cloud.vault.elasticsearch.role

Role name for credentials.

spring.cloud.vault.elasticsearch.static-role

false

Enable static role usage.

spring.cloud.vault.elasticsearch.username-property

spring.elasticsearch.rest.username

Target property for the obtained username.

spring.cloud.vault.enabled

true

Enable Vault config server.

spring.cloud.vault.fail-fast

false

Fail fast if data cannot be obtained from Vault.

spring.cloud.vault.gcp-gce.gcp-path

gcp

Mount path of the Kubernetes authentication backend.

spring.cloud.vault.gcp-gce.role

Name of the role against which the login is being attempted.

spring.cloud.vault.gcp-gce.service-account

Optional service account id. Using the default id if left unconfigured.

spring.cloud.vault.gcp-iam.credentials.encoded-key

The base64 encoded contents of an OAuth2 account private key in JSON format.

spring.cloud.vault.gcp-iam.credentials.location

Location of the OAuth2 credentials private key. <p> Since this is a Resource, the private key can be in a multitude of locations, such as a local file system, classpath, URL, etc.

spring.cloud.vault.gcp-iam.gcp-path

gcp

Mount path of the Kubernetes authentication backend.

spring.cloud.vault.gcp-iam.jwt-validity

15m

Validity of the JWT token.

spring.cloud.vault.gcp-iam.project-id

Overrides the GCP project Id.

spring.cloud.vault.gcp-iam.role

Name of the role against which the login is being attempted.

spring.cloud.vault.gcp-iam.service-account-id

Overrides the GCP service account Id.

spring.cloud.vault.host

localhost

Vault server host.

spring.cloud.vault.kubernetes.kubernetes-path

kubernetes

Mount path of the Kubernetes authentication backend.

spring.cloud.vault.kubernetes.role

Name of the role against which the login is being attempted.

spring.cloud.vault.kubernetes.service-account-token-file

/var/run/secrets/kubernetes.io/serviceaccount/token

Path to the service account token file.

spring.cloud.vault.kv.application-name

application

Application name to be used for the context.

spring.cloud.vault.kv.backend

secret

Name of the default backend.

spring.cloud.vault.kv.backend-version

2

Key-Value backend version. Currently supported versions are: <ul> <li>Version 1 (unversioned key-value backend).</li> <li>Version 2 (versioned key-value backend).</li> </ul>

spring.cloud.vault.kv.default-context

application

Name of the default context.

spring.cloud.vault.kv.enabled

true

Enable the kev-value backend.

spring.cloud.vault.kv.profile-separator

/

Profile-separator to combine application name and profile.

spring.cloud.vault.kv.profiles

List of active profiles. @since 3.0

spring.cloud.vault.mongodb.backend

mongodb

MongoDB backend path.

spring.cloud.vault.mongodb.enabled

false

Enable mongodb backend usage.

spring.cloud.vault.mongodb.password-property

spring.data.mongodb.password

Target property for the obtained password.

spring.cloud.vault.mongodb.role

Role name for credentials.

spring.cloud.vault.mongodb.static-role

false

Enable static role usage. @since 2.2

spring.cloud.vault.mongodb.username-property

spring.data.mongodb.username

Target property for the obtained username.

spring.cloud.vault.mysql.backend

mysql

mysql backend path.

spring.cloud.vault.mysql.enabled

false

Enable mysql backend usage.

spring.cloud.vault.mysql.password-property

spring.datasource.password

Target property for the obtained username.

spring.cloud.vault.mysql.role

Role name for credentials.

spring.cloud.vault.mysql.username-property

spring.datasource.username

Target property for the obtained username.

spring.cloud.vault.namespace

Vault namespace (requires Vault Enterprise).

spring.cloud.vault.pcf.instance-certificate

Path to the instance certificate (PEM). Defaults to {@code CF_INSTANCE_CERT} env variable.

spring.cloud.vault.pcf.instance-key

Path to the instance key (PEM). Defaults to {@code CF_INSTANCE_KEY} env variable.

spring.cloud.vault.pcf.pcf-path

pcf

Mount path of the Kubernetes authentication backend.

spring.cloud.vault.pcf.role

Name of the role against which the login is being attempted.

spring.cloud.vault.port

8200

Vault server port.

spring.cloud.vault.postgresql.backend

postgresql

postgresql backend path.

spring.cloud.vault.postgresql.enabled

false

Enable postgresql backend usage.

spring.cloud.vault.postgresql.password-property

spring.datasource.password

Target property for the obtained username.

spring.cloud.vault.postgresql.role

Role name for credentials.

spring.cloud.vault.postgresql.username-property

spring.datasource.username

Target property for the obtained username.

spring.cloud.vault.rabbitmq.backend

rabbitmq

rabbitmq backend path.

spring.cloud.vault.rabbitmq.enabled

false

Enable rabbitmq backend usage.

spring.cloud.vault.rabbitmq.password-property

spring.rabbitmq.password

Target property for the obtained password.

spring.cloud.vault.rabbitmq.role

Role name for credentials.

spring.cloud.vault.rabbitmq.username-property

spring.rabbitmq.username

Target property for the obtained username.

spring.cloud.vault.read-timeout

15000

Read timeout.

spring.cloud.vault.scheme

https

Protocol scheme. Can be either "http" or "https".

spring.cloud.vault.session.lifecycle.enabled

true

Enable session lifecycle management.

spring.cloud.vault.session.lifecycle.expiry-threshold

7s

The expiry threshold for a {@link LoginToken}. The threshold represents a minimum TTL duration to consider a login token as valid. Tokens with a shorter TTL are considered expired and are not used anymore. Should be greater than {@code refreshBeforeExpiry} to prevent token expiry.

spring.cloud.vault.session.lifecycle.refresh-before-expiry

5s

The time period that is at least required before renewing the {@link LoginToken}.

spring.cloud.vault.ssl.cert-auth-path

cert

Mount path of the TLS cert authentication backend.

spring.cloud.vault.ssl.enabled-cipher-suites

List of enabled SSL/TLS cipher suites. @since 3.0.2

spring.cloud.vault.ssl.enabled-protocols

List of enabled SSL/TLS protocol. @since 3.0.2

spring.cloud.vault.ssl.key-store

Trust store that holds certificates and private keys.

spring.cloud.vault.ssl.key-store-password

Password used to access the key store.

spring.cloud.vault.ssl.key-store-type

Type of the key store. @since 3.0

spring.cloud.vault.ssl.trust-store

Trust store that holds SSL certificates.

spring.cloud.vault.ssl.trust-store-password

Password used to access the trust store.

spring.cloud.vault.ssl.trust-store-type

Type of the trust store. @since 3.0

spring.cloud.vault.token

Static vault token. Required if {@link #authentication} is {@code TOKEN}.

spring.cloud.vault.uri

Vault URI. Can be set with scheme, host and port.