This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Cloud Vault 4.1.4! |
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
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
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
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 supportedKeyStore
types includingPEM
. -
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.
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. -
lease-strategy
sets theLeaseStrategy
(DropOnError
,RetainOnError
,RetainOnIoError
) to control error handling on lease renewal.
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 subtractingrefresh-before-expiry
from the token expiry time. Defaults to5 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 thanrefresh-before-expiry
to prevent token expiry. Defaults to7 seconds
.
See also: Vault Documentation: Token Renewal