*: add CI job to synchronize Makefile.common across all repos (#5444)

Signed-off-by: paulfantom <pawel@krupa.net.pl>

.circleci/config.yml

@@ -98,6 +98,12 @@ jobs:
     - run: make docker-publish
     - run: make docker-publish DOCKER_REPO=quay.io/prometheus
 
+  makefile_sync:
+    executor: golang
+    steps:
+    - checkout
+    - run: ./scripts/sync_makefiles.sh
+
 workflows:
   version: 2
   prometheus:
@@ -126,3 +132,14 @@ workflows:
             only: /^v[0-9]+(\.[0-9]+){2}(-.+|[^-.]*)$/
           branches:
             ignore: /.*/
+  nightly:
+    triggers:
+      - schedule:
+          cron: "0 0 * * *"
+          filters:
+            branches:
+              only:
+                - master
+    jobs:
+      - makefile_sync
+    

scripts/sync_makefiles.sh

@@ -0,0 +1,65 @@
+#!/bin/bash
+
+set -uo pipefail
+
+# GITHUB_TOKEN required scope: repo.repo_public
+
+git_mail="prometheus-team@googlegroups.com"
+git_user="prombot"
+branch="makefile_common"
+commit_msg="makefile: update Makefile.common with newer version"
+pr_title="Synchronize Makefile.common from prometheus/prometheus"
+pr_msg="Propagating changes from master Makefile.common located in prometheus/prometheus."
+org="prometheus"
+
+GITHUB_TOKEN="${GITHUB_TOKEN:-}"
+if [ -z "${GITHUB_TOKEN}" ]; then
+	echo -e "\e[31mGitHub token (GITHUB_TOKEN) not set. Terminating.\e[0m"
+	exit 1
+fi
+
+# Go to the root of the repo
+cd "$(git rev-parse --show-cdup)"
+
+source_makefile="$(pwd)/Makefile.common"
+source_checksum="$(sha256sum Makefile.common | cut -d' ' -f1)"
+
+tmp_dir=$(mktemp -d)
+trap "rm -rf ${tmp_dir}" EXIT
+
+# iterate over all repositories in ${org}
+curl --retry 5 --silent -u "${git_user}:${GITHUB_TOKEN}" https://api.github.com/users/${org}/repos 2>/dev/null | jq -r '.[] | select( .name != "prometheus" ) | .name' | while read -r; do
+	repo="${REPLY}"
+	echo -e "\e[32mAnalyzing '${repo}'\e[0m"
+
+	target_makefile="$(curl -s --fail "https://raw.githubusercontent.com/${org}/${repo}/master/Makefile.common")"
+	if [ -z "${target_makefile}" ]; then
+		echo "Makefile.common doesn't exist in ${repo}"
+		continue
+	fi
+	target_checksum="$(echo ${target_makefile} | sha256sum | cut -d' ' -f1)"
+	if [ "${source_checksum}" == "${target_checksum}" ]; then
+		echo "Makefile.common is already in sync."
+		continue
+	fi
+
+	# Clone target repo to temporary directory and checkout to new branch
+	git clone "https://github.com/${org}/${repo}.git" "${tmp_dir}/${repo}"
+	cd "${tmp_dir}/${repo}"
+	git checkout -b "${branch}"
+
+	# Replace Makefile.common in target repo by one from prometheus/prometheus
+	cp -f "${source_makefile}" ./
+	if [ -n "$(git status --porcelain)" ]; then
+		git config user.email "${git_mail}"
+		git config user.name "${git_user}"
+		git add .
+		git commit -s -m "${commit_msg}"
+		if git push "https://${GITHUB_TOKEN}:@github.com/${org}/${repo}" --set-upstream "${branch}"; then
+			curl -u "${git_user}:${GITHUB_TOKEN}" \
+				-X POST \
+				-d "{\"title\":\"${pr_title}\",\"base\":\"master\",\"head\":\"${branch}\",\"body\":\"${pr_msg}\"}" \
+				"https://api.github.com/repos/${org}/${repo}/pulls"
+		fi
+	fi
+done