8.2. Cartridge Event Subscriptions

When OpenShift Enterprise adds a cartridge to an application, it uses entries in the Subscribes section of the $cartridge_name/metadata/manifest.yml file in other cartridges to determine what actions to take for those other cartridges. Define subscribe events in the manifest.yml file using the following format: 
Subscribes:
  <event_name>:
    Type: "<event type>"

Example 8.2. PHP Cartridge Subscribes Entry

Subscribes:
  set-env:
    Type: "ENV:*"
    Required: false
  set-mysql-connection-info:
    Type: "NET_TCP:db:mysql"
    Required: false
  set-postgres-connection-info:
    Type: "NET_TCP:db:postgres"
    Required: false
  set-doc-url:
    Type: "STRING:urlpath"
    Required: false
When OpenShift Enterprise processes a cartridge publish script, it inputs the result to subscriber scripts in other cartridges that match the Type of the publish event. The input to matching subscriber scripts is prefaced with $cartridge_name/hooks/<event_name> <gear_name> <namespace> <gear_uuid>.
For each matching Subscribes entry, OpenShift Enterprise runs a script named $cartridge_name/hooks/$event_name. OpenShift Enterprise must send and process entries marked with Required: true.
The publisher script determines the format of the information input to the subscriber script. Ensure that subscriber script can parse the input correctly.