Retry if the PR is unrebaseable (cirrus-actions#75)

* Retry if the PR is unrebaseable

* Remove useless code

(cherry picked from commit 1eb6e5e)

entrypoint.sh

@@ -4,48 +4,67 @@ set -e
 
 PR_NUMBER=$(jq -r ".pull_request.number" "$GITHUB_EVENT_PATH")
 if [[ "$PR_NUMBER" == "null" ]]; then
-  PR_NUMBER=$(jq -r ".issue.number" "$GITHUB_EVENT_PATH")
+	PR_NUMBER=$(jq -r ".issue.number" "$GITHUB_EVENT_PATH")
 fi
 if [[ "$PR_NUMBER" == "null" ]]; then
-  echo "Failed to determine PR Number."
-  exit 1
+	echo "Failed to determine PR Number."
+	exit 1
 fi
 echo "Collecting information about PR #$PR_NUMBER of $GITHUB_REPOSITORY..."
 
 if [[ -z "$GITHUB_TOKEN" ]]; then
-  echo "Set the GITHUB_TOKEN env variable."
-  exit 1
+	echo "Set the GITHUB_TOKEN env variable."
+	exit 1
 fi
 
 URI=https://api.github.com
 API_HEADER="Accept: application/vnd.github.v3+json"
 AUTH_HEADER="Authorization: token $GITHUB_TOKEN"
 
-pr_resp=$(curl -X GET -s -H "${AUTH_HEADER}" -H "${API_HEADER}" \
-  "${URI}/repos/$GITHUB_REPOSITORY/pulls/$PR_NUMBER")
+MAX_RETRIES=${MAX_RETRIES:-6}
+RETRY_INTERVAL=${RETRY_INTERVAL:-10}
+REBASEABLE=""
+pr_resp=""
+for ((i = 0 ; i < $MAX_RETRIES ; i++)); do
+	pr_resp=$(curl -X GET -s -H "${AUTH_HEADER}" -H "${API_HEADER}" \
+		"${URI}/repos/$GITHUB_REPOSITORY/pulls/$PR_NUMBER")
+	REBASEABLE=$(echo "$pr_resp" | jq -r .rebaseable)
+	if [[ "$REBASEABLE" == "null" ]]; then
+		echo "The PR is not ready to rebase, retry after $RETRY_INTERVAL seconds"
+		sleep $RETRY_INTERVAL
+		continue
+	else
+		break
+	fi
+done
+
+if [[ "$REBASEABLE" != "true" ]] ; then
+	echo "GitHub doesn't think that the PR is rebaseable!"
+	exit 1
+fi
 
 BASE_REPO=$(echo "$pr_resp" | jq -r .base.repo.full_name)
 BASE_BRANCH=$(echo "$pr_resp" | jq -r .base.ref)
 
 USER_LOGIN=$(jq -r ".comment.user.login" "$GITHUB_EVENT_PATH")
 
 user_resp=$(curl -X GET -s -H "${AUTH_HEADER}" -H "${API_HEADER}" \
-  "${URI}/users/${USER_LOGIN}")
+	"${URI}/users/${USER_LOGIN}")
 
 USER_NAME=$(echo "$user_resp" | jq -r ".name")
 if [[ "$USER_NAME" == "null" ]]; then
-  USER_NAME=$USER_LOGIN
+	USER_NAME=$USER_LOGIN
 fi
 USER_NAME="${USER_NAME} (Rebase PR Action)"
 
 USER_EMAIL=$(echo "$user_resp" | jq -r ".email")
 if [[ "$USER_EMAIL" == "null" ]]; then
-  USER_EMAIL="$USER_LOGIN@users.noreply.github.com"
+	USER_EMAIL="$USER_LOGIN@users.noreply.github.com"
 fi
 
 if [[ -z "$BASE_BRANCH" ]]; then
-  echo "Cannot get base branch information for PR #$PR_NUMBER!"
-  exit 1
+	echo "Cannot get base branch information for PR #$PR_NUMBER!"
+	exit 1
 fi
 
 HEAD_REPO=$(echo "$pr_resp" | jq -r .head.repo.full_name)