TriggerBindings

As per the name, TriggerBindings bind against events/triggers.TriggerBindings enable you to capture fields from an event and store them asparameters. The separation of TriggerBindings from TriggerTemplates wasdeliberate to encourage reuse between them.

apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
  name: pipeline-binding
spec:
  params:
  - name: gitrevision
    value: $(body.head_commit.id)
  - name: gitrepositoryurl
    value: $(body.repository.url)
  - name: contenttype
    value: $(header.Content-Type)

TriggerBindings are connected to TriggerTemplates within anEventListener, which is where the pod is actuallyinstantiated that “listens” for the respective events.

Parameters

TriggerBindings can provide params which are passed to a TriggerTemplate.Each parameter has a name and a value.

Event Variable Interpolation

TriggerBindings can access values from the HTTP JSON body and the headers usingJSONPath expressions wrapped in $(). The key in the header iscase-insensitive.

These are all valid expressions:

$(body.key1)
$(.body.key)

These are invalid expressions:

.body.key1 # INVALID - Not wrapped in $()
$({body) # INVALID - Ending curly brace absent

If the $() is embedded inside another $() we will use the contents of theinnermost $() as the JSONPath expression

$($(body.b)) -> $(body.b)
$($($(body.b))) -> $(body.b)

Examples

`$(body)` is replaced by the entire body.
$(body) -> "{"key1": "value1", "key2": {"key3": "value3"}, "key4": ["value4", "value5", "value6"]}"
$(body.key1) -> "value1"
$(body.key2) -> "{"key3": "value3"}"
$(body.key2.key3) -> "value3"
$(body.key4[0]) -> "value4"
$(body.key4[0:2]) -> "{"value4", "value5"}"
# $(header) is replaced by all of the headers from the event.
$(header) -> "{"One":["one"], "Two":["one","two","three"]}"
$(header.One) -> "one"
$(header.one) -> "one"
$(header.Two) -> "one two three"
$(header.Two[1]) -> "two"

Multiple Bindings

In an EventListener, you may specify multiple bindings aspart of your trigger. This allows you to create reusable bindings that can bemixed and matched with various triggers. For example, a trigger with one bindingthat extracts event information, and another binding that provides deployenvironment information:

apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
  name: event-binding
spec:
  params:
    - name: gitrevision
      value: $(body.head_commit.id)
    - name: gitrepositoryurl
      value: $(body.repository.url)
---
apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
  name: prod-env
spec:
  params:
    - name: environment
      value: prod
---
apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
  name: staging-env
spec:
  params:
    - name: environment
      value: staging
---
apiVersion: triggers.tekton.dev/v1alpha1
kind: EventListener
metadata:
  name: listener
spec:
  triggers:
    - name: prod-trigger
      bindings:
        - name: event-binding
        - name: prod-env
      template:
        name: pipeline-template
    - name: staging-trigger
      bindings:
        - name: event-binding
        - name: staging-env
      template:
        name: pipeline-template