update-repos

#!/bin/bash

# Synchronizes all the branches from the CoreOS upstream to the flatcar-linux
# organization clones.

set -euo pipefail

. ./lib/common.sh

# update-branches gets all the upstream branches, checks them out and pushes to
# the origin.
#
# It assumes upstream and origin remotes are created and up to date.
function update-branches() {
  local UPSTREAM="${1}"
  local ORIGIN="${2}"
  local PUSH_TAGS="${3}"
  local UPSTREAM_BRANCHES

  # Exclude branches that contain "flatcar", "edge", or "main" and would overwrite our branches
  # TODO: This should be configured per repo or we retire this script and rely on manual work
  UPSTREAM_BRANCHES=$(git branch -r | grep "^[ ]*$UPSTREAM" | grep -v HEAD | cut -d/ -f 2- | grep -v flatcar | grep -v main | grep -v edge)

  for branch in ${UPSTREAM_BRANCHES}; do
    git checkout -B "${branch}" "${UPSTREAM}/${branch}"
  done

  # use the --force, Luke!
  git push --all --force "${ORIGIN}"

  # push tags only if PUSH_TAGS is true
  if [[ ${PUSH_TAGS} == "1" ]] ; then
    git push --tags "${ORIGIN}"
  fi
}

# Merge each upstream systemd branch to Flatcar branch, e.g. v241-coreos to v241-flatcar.
# We need to deal with the special case, because of the special case of systemd repo,
# which has no base point like "flatcar-master" branch. So if upstream has updated
# the v241-coreos branch, that change needs to be also applied to v241-flatcar.
function update-systemd-branches() {
  local UPSTREAM="${1}"
  local FLATCAR_BRANCH="${2}"
  local ORIGIN="origin"
  local UPSTREAM_BRANCHES

  UPSTREAM_BRANCHES=$(git branch -r | grep "^[ ]*$UPSTREAM/v2[4-9][1-9]" | grep -v HEAD | cut -d/ -f 2-)

  for upstream_branch in ${UPSTREAM_BRANCHES}; do
    local flatcar_branch
    flatcar_branch="${upstream_branch//-${UPSTREAM}/-${FLATCAR_BRANCH}}"

    if [[ -n "$(git ls-remote ${ORIGIN} ${flatcar_branch} 2>/dev/null)" ]]; then
      git checkout -B "${flatcar_branch}" "${ORIGIN}/${flatcar_branch}"
      git merge "${UPSTREAM}/${upstream_branch}"
      git push "${ORIGIN}" "${flatcar_branch}"
    fi
  done
}

PREFIX=""
if [ $# -eq 1 ]; then
    PREFIXTMP="$1"
    if [ -d "${PWD}/${PREFIXTMP}" ]; then
        PREFIX="${PREFIXTMP}"
        echo "Using existing directory $PREFIX"
        # we're not cleaning up this one since it's user provided
    fi
fi

if [ -z "${PREFIX}" ]; then
    PREFIX=$(mktemp -d "${PWD}/.update-repos.XXXXXXXXXX")
    echo "Created new directory $PREFIX"
    # clean up
    trap '{ export EXT="$?"; rm -rf "${PREFIX}" && exit "${EXT}"; }' EXIT
fi

cd "${PREFIX}"


for repo in "${FLATCAR_REPOS[@]}"; do
  # Systemd is handled below
  if [ "${repo}" = "systemd" ]; then
    continue
  fi
  [ ! -d "${repo}" ] && git clone "git@github.com:flatcar-linux/${repo}"

  pushd "${repo}"
  git remote add upstream "https://github.com/coreos/${repo}" || true
  git fetch --all
  update-branches upstream origin 1

  popd
done

# The systemd stable repo is our upstream, not coreos/systemd
repo_systemd="systemd"

[ ! -d "${repo_systemd}" ] && git clone "git@github.com:flatcar-linux/${repo_systemd}"

pushd "${repo_systemd}"
git remote add upstream "https://github.com/systemd/systemd-stable" || true
git fetch --all
update-branches upstream origin 1

popd