Use tagged version in bugbug hooks (#640)

Fixes #634

.taskcluster.yml

@@ -268,7 +268,7 @@ tasks:
               - "git clone --quiet ${repository} &&
                  cd bugbug &&
                  git -c advice.detachedHead=false checkout ${head_rev} &&
-                 python infra/set_hook_env_var.py TAG $VERSION infra/taskcluster-hook-annotate.json &&
+                 python infra/set_hook_version.py $VERSION infra/taskcluster-hook-annotate.json &&
                  taskboot --target . build-hook infra/taskcluster-hook-annotate.json project-relman bugbug-annotate"
           metadata:
             name: bugbug update annotate hook
@@ -303,7 +303,7 @@ tasks:
               - "git clone --quiet ${repository} &&
                  cd bugbug &&
                  git -c advice.detachedHead=false checkout ${head_rev} &&
-                 python infra/set_hook_env_var.py TAG $VERSION infra/taskcluster-hook-pipeline-start.json &&
+                 python infra/set_hook_version.py $VERSION infra/taskcluster-hook-pipeline-start.json &&
                  taskboot --target . build-hook infra/taskcluster-hook-pipeline-start.json project-relman bugbug"
           routes:
             - project.relman.bugbug.deploy_ending
@@ -339,7 +339,7 @@ tasks:
               - "git clone --quiet ${repository} &&
                  cd bugbug &&
                  git -c advice.detachedHead=false checkout ${head_rev} &&
-                 python infra/set_hook_env_var.py TAG $VERSION infra/taskcluster-hook-check-models-start.json &&
+                 python infra/set_hook_version.py $VERSION infra/taskcluster-hook-check-models-start.json &&
                  taskboot --target . build-hook infra/taskcluster-hook-check-models-start.json project-relman bugbug-checks"
           metadata:
             name: bugbug update check hook

infra/set_hook_version.py

@@ -11,16 +11,10 @@ import sys
 def main(raw_args):
     parser = argparse.ArgumentParser()
     parser.add_argument(
-        "env_name",
-        metavar="env-name",
+        "version",
+        metavar="version",
         type=str,
-        help="The name of the environment variable to set",
-    )
-    parser.add_argument(
-        "env_value",
-        metavar="env-value",
-        type=str,
-        help="The value of the environment variable to set",
+        help="The version to set in the hook definition",
     )
     parser.add_argument(
         "hook_file",
@@ -34,9 +28,17 @@ def main(raw_args):
     with open(args.hook_file, "r") as hook_file:
         hook_data = json.load(hook_file)
 
-    # Insert or replace the environment variable
-    hook_env = hook_data["task"]["payload"]["env"]
-    hook_env[args.env_name] = args.env_value
+    task_payload = hook_data["task"]["payload"]
+
+    task_image = task_payload.get("image")
+
+    # 1) Insert or replace the environment variable
+    hook_env = task_payload["env"]
+    hook_env["TAG"] = args.version
+
+    # 2) Set the version for the hook docker image
+    if task_image and task_image.split(":", 1)[0] == "mozilla/bugbug-spawn-pipeline":
+        task_payload["image"] = f"mozilla/bugbug-spawn-pipeline:{args.version}"
 
     with open(args.hook_file, "w") as hook_file:
         json.dump(