In addition to marketplace services, Cloud Foundry supports User Provided Services (UPS). Throughout this reference manual, regular services have been mentioned, but there is nothing precluding the use of UPSs as well, whether for use as the messaging middleware (e.g. if you’d like to use an external Apache Kafka installation) or for ad hoc usage by some of the stream apps (e.g. an Oracle Database).
Let’s review an example of extracting and supplying the connection credentials from an UPS.
cf create-user-provided-service kafkacups -p '{”brokers":"HOST:PORT","zkNodes":"HOST:PORT"}'VCAP_SERVICES and it can be supplied directly in the stream definition like
the following.stream create fooz --definition "time | log"
stream deploy fooz --properties "app.time.spring.cloud.stream.kafka.binder.brokers=${vcap.services.kafkacups.credentials.brokers},app.time.spring.cloud.stream.kafka.binder.zkNodes=${vcap.services.kafkacups.credentials.zkNodes},app.log.spring.cloud.stream.kafka.binder.brokers=${vcap.services.kafkacups.credentials.brokers},app.log.spring.cloud.stream.kafka.binder.zkNodes=${vcap.services.kafkacups.credentials.zkNodes}"