8.2. Triggering Kubernetes resources

Kubernetes resources do not have fields for triggering, unlike deployment and build configurations, which include as part of their API definition a set of fields for controlling triggers. Instead, you can use annotations in OpenShift Container Platform to request triggering.

The annotation is defined as follows:

Key: image.openshift.io/triggers
Value:
[
 {
   "from": {
     "kind": "ImageStreamTag", 
     "name": "example:latest", 
     "namespace": "myapp" 
   },
   "fieldPath": "spec.template.spec.containers[?(@.name==\"web\")].image", 
   "paused": "false" 
 },
 ...
]

Key: image.openshift.io/triggers
Value:
[
 {
   "from": {
     "kind": "ImageStreamTag", 

     "name": "example:latest", 

     "namespace": "myapp" 

   },
   "fieldPath": "spec.template.spec.containers[?(@.name==\"web\")].image", 

   "paused": "false" 

 },
 ...
]

When one of the core Kubernetes resources contains both a pod template and this annotation, OpenShift Container Platform attempts to update the object by using the image currently associated with the image stream tag that is referenced by trigger. The update is performed against the fieldPath specified.

Examples of core Kubernetes resources that can contain both a pod template and annotation include: