If you have a shared service such as Hadoop where all applications will ultimately bind to the same service with the same credentials then you have found the service broker for you - the World's Simplest Service Broker for Cloud Foundry.
You configure it with a simple environment variable CREDENTIALS (the same JSON object that will be returned for all service bindings); and then register it as a service broker.
All services created and all service bindings will be given the same set of credentials. Definitely the simplest thing that could work.
As the admin of a service sharing it via a service broker - see section Deploy to Cloud Foundry for setup.
As a user of the broker:
cf cs myservice some-service-name
cf bs my-app some-service-name
cf restage my-app
Cloud Foundry includes "user-provided services" (see cf cups in the CLI) for easy registration of existing external service credentials.
The restriction for "cups" is that it is limited to the Space into which it was registered. For each organization/space, the cf cups command needs to be run. That is, when you create a new space, it does not immediately have access to the credentials for the service.
Instead, with the World's Simplest Service Broker you can make the credentials easily and instantly available to all organizations' spaces.
godep get
export BASE_GUID=$(uuid)
export CREDENTIALS='{"port": "4000", "host": "1.2.3.4"}'
export SERVICE_NAME=myservice
export SERVICE_PLAN_NAME=shared
export TAGS=simple,shared
worlds-simplest-service-broker
export SERVICE=myservice
export APPNAME=$SERVICE-broker
cf push $APPNAME --no-start -m 128M -k 256M
cf set-env $APPNAME BASE_GUID $(uuid)
cf set-env $APPNAME CREDENTIALS '{"port": "4000", "host": "1.2.3.4"}'
cf set-env $APPNAME SERVICE_NAME $SERVICE
cf set-env $APPNAME SERVICE_PLAN_NAME shared
cf set-env $APPNAME TAGS simple,shared
cf env $APPNAME
cf start $APPNAME
To register the service broker (as an admin user):
export SERVICE_URL=$(cf app $APPNAME | grep urls: | awk '{print $2}')
cf create-service-broker $SERVICE admin admin https://$SERVICE_URL
cf enable-service-access $SERVICE
To change the credentials being offered for bindings:
export SERVICE=myservice
export APPNAME=$SERVICE-broker
cf set-env $APPNAME CREDENTIALS '{"port": "4000", "host": "1.2.3.4"}'
cf restart $APPNAME
Each application will need rebind and restart/restage to get the new credentials.
Set the environment variables AUTH_USER and AUTH_PASSWORD to enable basic authentication for the broker.
This is useful to prevent unauthorized access to the credentials exposed by the broker (e.g. by somebody doing a curl -X PUT http://$SERVICE_URL/v2/service_instances/a/service_bindings/b).
To do so (of course, change secret_user and secret_password to something more secret):
cf set-env $APPNAME AUTH_USER secret_user
cf set-env $APPNAME AUTH_PASSWORD secret_password
cf restart $APPNAME
cf update-service-broker $SERVICE secret_user secret_password https://$SERVICE_URL
The broker can advertise a syslog_drain_url endpoint with the $SYSLOG_DRAIN_URL variable:
cf set-env $APPNAME SYSLOG_DRAIN_URL 'syslog://1.2.3.4:514'
Each service instance is assigned the same dashboard URL - /dashboard.
Adding image url to service broker
cf set-env $APPNAME IMAGE_URL '<image url>'