apertis-pkg-merge-upstream-to-downstreams: cancel pipelines created through...

apertis-pkg-merge-upstream-to-downstreams: cancel pipelines created through the creation of a branch

Due to GitLab limitation (https://gitlab.com/gitlab-org/gitlab/-/issues/26422

),
it's currently impossible to avoid to trigger a pipeline when creating a
branch with the API. Since these useless pipelines are wasting
GitLab and OBS ressources (and devs' time), as a workaround for now
we can cancel them.

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

tools/apertis-pkg-merge-upstream-to-downstreams

@@ -17,6 +17,8 @@ import urllib.request
 import urllib.parse
 import dataclasses
 import sys
+import json
+import time
 
 
 @dataclasses.dataclass
@@ -74,6 +76,48 @@ def is_minor_change(upstream, downstream):
   o = git('diff', '--exit-code', upstream, downstream, ':!debian/changelog', ':!debian/apertis/*', _ok_code=[0,1])
   return o.exit_code == 0
 
+def cancel_branch_context_pipeline(project_id, branch, token, project_url):
+  project_url = urllib.parse.urlsplit(project_url)
+
+  latest_branch_url = project_url._replace(
+      path=f"/api/v4/projects/{project_id}/pipelines/latest?ref={branch}",
+  ).geturl()
+
+  get_id_req = urllib.request.Request(
+      url=latest_branch_url,
+      headers={"PRIVATE-TOKEN": token},
+  )
+
+  n_wait = 2
+  print(f'Waiting {n_wait} seconds to ensure GitLab had enough time to trigger a pipeline')
+  time.sleep(n_wait)
+
+  try:
+      res = urllib.request.urlopen(get_id_req)
+      json_res = json.load(res)
+      print(json_res)
+      latest_job_id = json_res["id"]
+  except urllib.error.HTTPError as e:
+      print("ERROR:", e.read().decode())
+      return
+
+  cancel_url = project_url._replace(
+      path=f"/api/v4/projects/{project_id}/pipelines/{latest_job_id}/cancel",
+  ).geturl()
+
+  cancel_req = urllib.request.Request(
+      url=cancel_url,
+      method="POST",
+      headers={"PRIVATE-TOKEN": token},
+  )
+
+  print(f"Canceling useless pipeline on {branch}")
+  try:
+      res = urllib.request.urlopen(cancel_req).read().decode('utf-8')
+      print(res)
+  except urllib.error.HTTPError as e:
+      print("ERROR:", e.read().decode())
+
 def ensure_downstream_branch(project_url, downstream, dry_run):
   if parse_ref(f"origin/{downstream}"):
       return
@@ -91,6 +135,9 @@ def ensure_downstream_branch(project_url, downstream, dry_run):
   project_branches_url = url.geturl()
   # TODO: add `ci.skip` once it is available from the API
   # https://gitlab.com/gitlab-org/gitlab/-/issues/26422
+  # For now, let's cancel the pipeline newly created
+  # to avoid useless pipelines wasting GitLab and OBS ressources. This is only
+  # a workaround until #26422 is fixed.
   data = {"branch": urllib.parse.quote(downstream), "ref": downstream_commit}
   print(f"POST'ing to {project_branches_url}: {data}")
   req = urllib.request.Request(
@@ -103,6 +150,8 @@ def ensure_downstream_branch(project_url, downstream, dry_run):
     if not dry_run:
       res = urllib.request.urlopen(req).read().decode('utf-8')
       print(res)
+      # TODO: remove me once #26422 is fixed
+      cancel_branch_context_pipeline(project_id, downstream, token, project_branches_url)
   except urllib.error.HTTPError as e:
       print("ERROR:", e.read().decode())
       raise