Get GitHub or GitLab upstream repo URL

repo-get-upstream-url.sh

#!/usr/bin/env bash

repo_upstream_url() {
  local repo_url
  local repo_host
  local repo_path
  local repo_upstream
  local repo_api_private_token
  local repo_api_url
  local repo_api_key

  repo_url=`git remote get-url origin 2> /dev/null`

  if [ -z "$repo_url" ]; then
    echo "no remote origin url"
    return 1
  fi

  repo_host=`echo "$repo_url" | sed -e 's|.*://||' -e 's|git@||' -Ee 's|([^/:]+).*|\1|'`
  repo_path=`echo "$repo_url" | sed -e 's|.*://||' -e 's|git@||' -e 's|:|/|' -e 's|^[^/]*/||' -e 's|.git$||'`

  if [ -z "$repo_host" ] || [ -z "$repo_path" ]; then
    echo "no repo host or repo path"
    return 1
  fi

  case $repo_host in
    github.com)
      repo_api_url=https://api.github.com/repos/$repo_path
      repo_api_key=.source.clone_url
      ;;
    *)
      repo_api_private_token=`awk -F'[:=]' '$1==host && $2==property { print $3 }' host="$repo_host" property=private_token ~/.gitlabrc 2> /dev/null`

      if [ -n "$repo_api_private_token" ]; then
        repo_api_url="https://$repo_host/api/v4/projects/`echo $repo_path | xxd -plain | tr -d '\n' | sed 's/\(..\)/%\1/g'`?private_token=$repo_api_private_token"
        repo_api_key=.forked_from_project.http_url_to_repo
      fi
      ;;
  esac

  if [ -z "$repo_api_url" ] || [ -z "$repo_api_key" ]; then
    echo "no api url or object key"
    return 1
  fi

  repo_upstream=`wget -qO- "$repo_api_url" | jq -r "if $repo_api_key != null then $repo_api_key else \"\" end"`

  if [ -z "$repo_upstream" ]; then
    echo "no upstream found"
    return 1
  fi

  echo $repo_upstream
}