JS Bin's deploy script, run using `deploy jsbin/jsbin` (though the argument should probably just be hard coded since jsbin appears in the source)

deploy.sh

#!/bin/bash
readonly ARGS="$@"
readonly DEPLOY_USER="www-data"

clone_repo_at_tag() {
  local repo="$1"
  local tag="$2"
  local project_name="$3"
  local repo_dirname="$project_name-$tag"

  echo ">>> cloning $tag..."
  git clone --depth 1 -b $tag https://github.com/$repo.git $repo_dirname &> /dev/null
  if [ $? -ne 0 ]
  then
    echo "*** clone failed"
    exit 1
  fi
  build $repo_dirname
}

diff_deps() {
  echo ">>> diffing dependencies"
  local repo_dirname="$1"
  diff -B <(cat jsbin/package.json | json dependencies) <(cat $repo_dirname/package.json | json dependencies)
  if [ $? -ne 0 ]
  then
    echo "*** package diff failed"
    exit 1
  fi
}

build() {
  local repo_dirname="$1"
  local d=$(diff_deps $repo_dirname)

  cd $repo_dirname

  echo ">>> copying node modules from v$(json -f ../jsbin/package.json version)..."
  cp -R ../jsbin/node_modules .

  if [ $? -ne 0 ]
  then
    echo "*** copy previous version of modules failed"
    exit 1
  fi

  if [ -z "$d" ]; then
    echo ">>> no update required"
  else
    echo ">>> updating npm modules"
    npm install &> /dev/null

    if [ $? -ne 0 ]
    then
      echo "*** npm install failed"
      exit 1
    fi
  fi


  echo ">>> running build..."
  grunt build &> /dev/null

  if [ $? -ne 0 ]
  then
    echo "*** grunt build failed"
    exit 1
  fi
}

symlink_repo_to_name() {
  local repodir="$1"
  local project_name="$2"

  echo ">>> symlinking $repodir"
  ln -nfs /WWW/$repodir /WWW/$project_name
}

get_latest_tag() {
  local repo="$1"
  curl -s https://api.github.com/repos/$repo/tags | json 0.name
}

restart_jsbin() {
  echo ">>> restarting..."
  sudo restart jsbin
}

update_repo_and_symlinks() {
  local cwd=$(pwd)
  local args="$@"

  cd /WWW/
  local current_version=$(json -f jsbin/package.json version)
  # read the arg first, or get it from the environment value
  local repo=${1:-$REPO}
  local tag=$(get_latest_tag $repo)
  local project_name=$(echo $repo | awk -F'/' '{print $2}')

  clone_repo_at_tag $repo $tag $project_name
  cd $cwd

  symlink_repo_to_name "$project_name-$tag" $project_name
}

run_as_deploy_user() {
  echo "*** launching deploy as $DEPLOY_USER"
  sudo -Hu "$DEPLOY_USER" -- sh -c "$0 $ARGS"
  if [ $? -ne 0 ]
  then
    echo "*** deploy failed"
    exit 1
  fi
}

main() {
  if [ "$USER" != $DEPLOY_USER ]
  then
    run_as_deploy_user
    restart_jsbin
    echo ">>> deploy complete"
    exit 0
  else
    update_repo_and_symlinks $ARGS
    exit 0
  fi
}

main $ARGS