commit-msg-verify.sh

#!/usr/bin/env bash

set -o errexit
set -o nounset
set -o pipefail

pattern="^(Revert \")?OCM-[0-9]+ \| (feat|fix|docs|style|refactor|test|chore|build|ci|perf)(\\([a-z0-9._-]+\\))?(!)?: .*$"

print_commit_message_error() {
  local message=$1
  cat <<EOF
$message
Expected format: OCM-XXXXX | <conventional-commit>
Example: OCM-12345 | feat(scope): add support for foo
Please check CONTRIBUTE.md for more details
EOF
}

extract_subject() {
  local message=$1
  local line=""

  while IFS= read -r line; do
    line="${line%$'\r'}"

    # Ignore commented template lines and blank lines.
    if [[ "$line" =~ ^[[:space:]]*# ]]; then
      continue
    fi
    if [[ -z "${line//[[:space:]]/}" ]]; then
      continue
    fi

    printf '%s' "$line"
    return 0
  done <<< "$message"

  return 1
}

validate_message() {
  local message=$1
  local subject=""

  if ! subject=$(extract_subject "$message"); then
    print_commit_message_error "Invalid commit message: empty subject"
    return 1
  fi

  if ! [[ $subject =~ $pattern ]]; then
    print_commit_message_error "Invalid commit message subject: $subject"
    return 1
  fi

  return 0
}

# commit-msg git hook mode:
# validate a single commit message passed as a file path.
if [ -n "${1:-}" ]; then
  message_file=$1
  if [ ! -f "$message_file" ]; then
    echo "Unable to read commit message file: $message_file"
    exit 1
  fi

  message=$(cat "$message_file")
  validate_message "$message" || exit 1
  exit 0
fi

# Local no-arg mode:
# commit message validation should happen in commit-msg hook mode (with message file argument).
# Without a message file, do not guess from previous commit state.
if [ -z "${JOB_SPEC:-}" ] && [ -z "${PULL_BASE_SHA:-}" ] && [ -z "${PULL_PULL_SHA:-}" ]; then
  echo "No commit message file provided; commit message is validated by commit-msg hook during commit."
  exit 0
fi

# This regex matches the pull number with an author from the job spec. Prow does not have a PULL_AUTHOR job var.
JOB_SPEC_VALUE=${JOB_SPEC:-}
PULL_NUMBER_VALUE=${PULL_NUMBER:-}
PULL_AUTHOR=""
if [ -n "$JOB_SPEC_VALUE" ] && [ -n "$PULL_NUMBER_VALUE" ]; then
  PULL_AUTHOR=$(echo "$JOB_SPEC_VALUE" | grep -Po "$PULL_NUMBER_VALUE,\"author\":\"\K[^\"]*" || true)
fi

resolve_default_branch_ref() {
  local default_ref=""
  local remote_head_branch=""

  default_ref=$(git symbolic-ref --quiet --short refs/remotes/origin/HEAD 2>/dev/null || true)
  if [ -n "$default_ref" ]; then
    printf '%s' "$default_ref"
    return 0
  fi

  remote_head_branch=$(git remote show origin 2>/dev/null | sed -n 's/.*HEAD branch: //p' | head -n 1 || true)
  if [ -n "$remote_head_branch" ] && [ "$remote_head_branch" != "(unknown)" ]; then
    printf 'origin/%s' "$remote_head_branch"
    return 0
  fi

  printf 'origin/HEAD'
}

# PULL_BASE_SHA and PULL_PULL_SHA are set in prow job
default_branch_ref=$(resolve_default_branch_ref)
default_merge_base=$(git merge-base "$default_branch_ref" HEAD 2>/dev/null || git merge-base HEAD HEAD)
PULL_BASE_SHA_VALUE="${PULL_BASE_SHA:-$default_merge_base}"
PULL_PULL_SHA_VALUE="${PULL_PULL_SHA:-HEAD}"

# Lists of GitHub users for whom the commit validation should be skipped:
# # This contains the bots used in the ROSA project
# * openshift-merge-bot[bot] - bot responsible for merigng MRs
# * openshift-ci[bot] - bot responsible for running tests / approvals
declare -a skip_pr_authors=(
  "openshift-ci[bot]"
  "openshift-merge-bot[bot]"
)
echo "The PR Author is \"${PULL_AUTHOR}\""
for skip_pr_author in "${skip_pr_authors[@]}"
do
  if [ "${PULL_AUTHOR}" = "${skip_pr_author}" ]; then
    echo "The commits created by this PR author (probably bot) should be skipped!!!"
    exit 0
  fi
done

commits=$(git rev-list --no-merges "$PULL_BASE_SHA_VALUE..$PULL_PULL_SHA_VALUE")
if [ -z "$commits" ]; then
  echo "No commits detected in range ${PULL_BASE_SHA_VALUE}..${PULL_PULL_SHA_VALUE}"
  exit 0
fi

for sha in $commits; do
  message=$(git log --format=%B -n 1 "$sha")
  validate_message "$message" || exit 1
done

echo "All commit messages are valid"