./github/scripts/auto-backport.py: use scylladbbot fork for backpor…

…t PRs

It seems that we can't push branches to the developer's fork due to permission issues (I managed to get it working during my verification, but maybe it was because I was testing it under my user)

Since all Dev team members in Github have Triage permissions, they can't update branches under the scylladb organization, Instead, I have added write permission on `scyllaadbbot` fork to provide access to all dev
This will allow everyone to update the backport branches directly when conflicts apply and in general

(cherry picked from commit f6c5d28)

.github/scripts/auto-backport.py

@@ -37,18 +37,17 @@ def create_pull_request(repo, new_branch_name, base_branch_name, pr, backport_pr
     for commit in commits:
         pr_body += f'- (cherry picked from commit {commit})\n\n'
     pr_body += f'Parent PR: #{pr.number}'
-    if is_draft:
-        new_branch_name = f'{pr.user.login}:{new_branch_name}'
     try:
         backport_pr = repo.create_pull(
             title=backport_pr_title,
             body=pr_body,
-            head=new_branch_name,
+            head=f'scylladbbot:{new_branch_name}',
             base=base_branch_name,
             draft=is_draft
         )
         logging.info(f"Pull request created: {backport_pr.html_url}")
         backport_pr.add_to_assignees(pr.user)
+        backport_pr.add_to_labels("conflicts") if is_draft else None
         logging.info(f"Assigned PR to original author: {pr.user}")
         return backport_pr
     except GithubException as e:
@@ -88,28 +87,25 @@ def get_pr_commits(repo, pr, stable_branch, start_commit=None):
     return commits
 
 
-def backport(repo, pr, version, commits, backport_base_branch, user):
+def backport(repo, pr, version, commits, backport_base_branch):
+    new_branch_name = f'backport/{pr.number}/to-{version}'
+    backport_pr_title = f'[Backport {version}] {pr.title}'
+    repo_url = f'https://scylladbbot:{github_token}@github.com/{repo.full_name}.git'
+    fork_repo = f'https://scylladbbot:{github_token}@github.com/scylladbbot/{repo.name}.git'
     with (tempfile.TemporaryDirectory() as local_repo_path):
         try:
-            new_branch_name = f'backport/{pr.number}/to-{version}'
-            backport_pr_title = f'[Backport {version}] {pr.title}'
-            repo_local = Repo.clone_from(f'https://{user.login}:{github_token}@github.com/{repo.full_name}.git', local_repo_path, branch=backport_base_branch)
+            repo_local = Repo.clone_from(repo_url, local_repo_path, branch=backport_base_branch)
             repo_local.git.checkout(b=new_branch_name)
-            fork_repo = pr.user.get_repo(repo.full_name.split('/')[1])
-            fork_repo_url = f'https://{user.login}:{github_token}@github.com/{fork_repo.full_name}.git'
-            repo_local.create_remote('fork', fork_repo_url)
-            remote = 'origin'
             is_draft = False
             for commit in commits:
                 try:
                     repo_local.git.cherry_pick(commit, '-m1', '-x')
                 except GitCommandError as e:
                     logging.warning(f'Cherry-pick conflict on commit {commit}: {e}')
-                    remote = 'fork'
                     is_draft = True
                     repo_local.git.add(A=True)
                     repo_local.git.cherry_pick('--continue')
-            repo_local.git.push(remote, new_branch_name, force=True)
+            repo_local.git.push(fork_repo, new_branch_name, force=True)
             create_pull_request(repo, new_branch_name, backport_base_branch, pr, backport_pr_title, commits,
                                 is_draft=is_draft)
         except GitCommandError as e:
@@ -121,25 +117,15 @@ def main():
     base_branch = args.base_branch.split('/')[2]
     promoted_label = 'promoted-to-master'
     repo_name = args.repo
-    if 'scylla-enterprise' in args.repo:
+    if 'scylla-enterprise-machine-image' in args.repo:
         promoted_label = 'promoted-to-enterprise'
-    if args.repo in ('scylladb/scylla', 'scylladb/scylla-enterprise'):
-        stable_branch = base_branch
-        backport_branch = 'branch-'
-    else:
-        backport_branch = 'next-'
-        if base_branch in ('master', 'next'):
-            stable_branch = 'master'
-        elif base_branch in ('enterprise', 'next-enterprise'):
-            stable_branch = 'enterprise'
-        else:
-            stable_branch = base_branch.replace('next', 'branch')
 
+    backport_branch = 'next-'
+    stable_branch = 'master' if base_branch == 'next' else 'enterprise' if base_branch == 'next-enterprise' else base_branch.replace('next', 'branch')
     backport_label_pattern = re.compile(r'backport/\d+\.\d+$')
 
     g = Github(github_token)
     repo = g.get_repo(repo_name)
-    user = g.get_user()
     closed_prs = []
     start_commit = None
 
@@ -168,7 +154,7 @@ def main():
         for backport_label in backport_labels:
             version = backport_label.replace('backport/', '')
             backport_base_branch = backport_label.replace('backport/', backport_branch)
-            backport(repo, pr, version, commits, backport_base_branch, user)
+            backport(repo, pr, version, commits, backport_base_branch)
 
 
 if __name__ == "__main__":