merge_bot: Handle merge conflicts
The bot cannot resolve those automatically. To ease the process, we
will upload the merge anyway, so the oncall can download and resolve
the conflict.
Dry runs are not created when there are conflicts, they are bound
to fail and there is nothing the oncall can do about conflicts
until the actual merge is generated.
BUG=b:234847583
TEST=MERGE_BOT_TEST=1 ./tools/chromeos/merge_bot update-merges / update-dry-runs
Change-Id: I409e6b99284ff8a98b504b390c35329875d6a8b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3689544
Reviewed-by: Anton Romanov <romanton@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/tools/chromeos/merge_bot b/tools/chromeos/merge_bot
index 3112f14..f742f24 100755
--- a/tools/chromeos/merge_bot
+++ b/tools/chromeos/merge_bot
@@ -9,6 +9,10 @@
# account (and are enabled with --is-bot).
#
# See `./tools/chromeos/merge_bot -h` for details.
+#
+# When testing this script locally, use MERGE_BOT_TEST=1 ./tools/chromeos/merge_bot
+# to use different tags that do not interfere with the ongoing merge process.
+
import functools
import os
@@ -218,10 +222,11 @@
commits = git_log(f"HEAD..{revision}", "--pretty=%H").lines()
if not commits:
print("Nothing to merge.")
- return 0
+ return (0, False)
# Create a merge commit for each batch
batches = list(batched(commits, max_size)) if max_size > 0 else [commits]
+ has_conflicts = False
for i, batch in enumerate(reversed(batches)):
target = batch[0]
previous_rev = git(f"rev-parse {batch[-1]}^").stdout()
@@ -235,7 +240,7 @@
f"{title} {date.today().isoformat()} {batch_str}",
git_log(commit_range, "--oneline").stdout(),
f"{UPSTREAM_URL}/+log/{commit_range}",
- bug_notes(commit_range),
+ *([bug_notes(commit_range)] if not create_dry_run else []),
]
)
@@ -243,9 +248,19 @@
trailers = "Commit: False" if create_dry_run else ""
# Perfom merge
- git("merge --no-ff", target, "-m", quoted(message), "-m", quoted(trailers)).fg()
+ code = git("merge --no-ff", target, "-m", quoted(message), "-m", quoted(trailers)).fg(
+ check=False
+ )
+ if code != 0:
+ if not Path(".git/MERGE_HEAD").exists():
+ raise Exception("git merge failed for a reason other than merge conflicts.")
+ print("Merge has conflicts. Creating commit with conflict markers.")
+ git("add --update .").fg()
+ message = f"(CONFLICT) {message}"
+ git("commit", "-m", quoted(message), "-m", quoted(trailers)).fg()
+ has_conflicts = True
- return len(batches)
+ return (len(batches), has_conflicts)
def status():
@@ -278,13 +293,14 @@
else:
print(f"Creating merge of {parsed_revision} into cros/{target_branch}")
setup_tracking_branch("merge-bot-branch", target_branch)
- if create_merge_commits(parsed_revision, max_size, create_dry_run=False) > 0:
- upload_to_gerrit(
- target_branch,
- f"hashtag={MERGE_TAG}",
- "l=Commit-Queue+1",
- *(["l=Bot-Commit+1"] if is_bot else []),
- )
+ count, has_conflicts = create_merge_commits(parsed_revision, max_size, create_dry_run=False)
+ if count > 0:
+ labels = []
+ if not has_conflicts:
+ labels.append("l=Commit-Queue+1")
+ if is_bot:
+ labels.append("l=Bot-Commit+1")
+ upload_to_gerrit(target_branch, f"hashtag={MERGE_TAG}", *labels)
def update_dry_runs(
@@ -343,13 +359,19 @@
print(f"Creating dry run merge of {parsed_revision} into cros/{target_branch}")
setup_tracking_branch("merge-bot-branch", target_branch)
- if create_merge_commits(parsed_revision, max_size, create_dry_run=True) > 0:
+ count, has_conflicts = create_merge_commits(parsed_revision, max_size, create_dry_run=True)
+ if count > 0 and not has_conflicts:
upload_to_gerrit(
target_branch,
f"hashtag={DRY_RUN_TAG}",
"l=Commit-Queue+1",
*(["l=Bot-Commit+1"] if is_bot else []),
)
+ else:
+ if has_conflicts:
+ print("Not uploading dry-run with conflicts.")
+ else:
+ print("Nothing to upload.")
run_commands(create_merge_commits, status, update_merges, update_dry_runs, gerrit_prerequisites)
