[fenix] RELENG-588: Add notifications for Mozilla Online builds (https://github.com/mozilla-mobile/fenix/pull/20010)

taskcluster/ci/signing/kind.yml

@@ -7,6 +7,7 @@ loader: fenix_taskgraph.loader.multi_dep:loader
 transforms:
     - fenix_taskgraph.transforms.multi_dep:transforms
     - fenix_taskgraph.transforms.signing:transforms
+    - fenix_taskgraph.transforms.notify:transforms
     - taskgraph.transforms.task:transforms
 
 kind-dependencies:
@@ -52,3 +53,18 @@ job-template:
         kind: build
         platform: android-all/opt
         tier: 1
+    notify:
+        by-build-type:
+            .*mozillaonline:
+                by-level:
+                    '3':
+                        email:
+                            content: The Mozilla Online Fenix {version} APKs are now available
+                            link:
+                                text: Taskcluster Task
+                                href: 'https://firefox-ci-tc.services.mozilla.com/tasks/${status.taskId}'
+                            on-reasons: [completed]
+                            subject: Mozilla Online Fenix {version} APKs are now available
+                            to-addresses: [mozillaonline-fenix@mozilla.com]
+                    default: {}
+            default: {}

taskcluster/fenix_taskgraph/transforms/signing.py

@@ -18,7 +18,7 @@ transforms = TransformSequence()
 @transforms.add
 def resolve_keys(config, tasks):
     for task in tasks:
-        for key in ("run-on-tasks-for", "signing-format"):
+        for key in ("run-on-tasks-for", "signing-format", "notify"):
             resolve_keyed_by(
                 task,
                 key,
@@ -90,3 +90,17 @@ def set_signing_format(config, tasks):
         for upstream_artifact in task["worker"]["upstream-artifacts"]:
             upstream_artifact["formats"] = [signing_format]
         yield task
+
+
+@transforms.add
+def format_email(config, tasks):
+    version = config.params["version"]
+
+    for task in tasks:
+        if "notify" in task:
+            email = task["notify"].get("email")
+            if email:
+                email["subject"] = email["subject"].format(version=version)
+                email["content"] = email["content"].format(version=version)
+
+        yield task