github.com/pquerna/agent@v2.1.8+incompatible/packaging/linux/scripts/after-install-and-upgrade.sh

# $1 will be the version being upgraded from if this is an upgrade
if [ "$1" = "" ] ; then
  OPERATION="install"
else
  OPERATION="upgrade"
fi

# Find out whether or not the buildkite-agent user exists
if [ -z "$(getent passwd buildkite-agent)" ]; then
  BK_USER_EXISTS="false"
else
  BK_USER_EXISTS="true"
fi

# Add the buildkite user if it doesn't exist on installation
if [ "$OPERATION" = "install" ] ; then
  if [ "$BK_USER_EXISTS" = "false" ]; then
    # Create the buildkite system user and set it's home to /var/lib/buildkite
    useradd --system --no-create-home -d /var/lib/buildkite-agent buildkite-agent

    # The user exists now!
    BK_USER_EXISTS=true
  fi

  # We create it's home folder in a seperate command so it doesn't blow up if
  # the folder already exists
  mkdir -p /var/lib/buildkite-agent
fi

# Create the /etc/buildkite-agent folder if it's not there
if [ ! -d /etc/buildkite-agent ]; then
  mkdir -p /etc/buildkite-agent
fi

# Install the config template if it's not there
if [ ! -f /etc/buildkite-agent/buildkite-agent.cfg ]; then
  cp /usr/share/buildkite-agent/buildkite-agent.cfg /etc/buildkite-agent/buildkite-agent.cfg

  # Set the default permission to 0600 so only the owning user can read/write to the file
  chmod 0600 /etc/buildkite-agent/buildkite-agent.cfg
fi

# Copy the hooks if they aren't there
if [ ! -d /etc/buildkite-agent/hooks ]; then
  cp -r /usr/share/buildkite-agent/hooks /etc/buildkite-agent
fi

# Check if systemd exists
command -v systemctl > /dev/null
BK_SYSTEMD_EXISTS=$?

# Check if the system is Ubuntu 14.10. Systemd is broken on this release, so if
# even if systemd exists on that system, skip using it.
command -v lsb_release > /dev/null && lsb_release -d | grep -q "Ubuntu 14.10"
BK_IS_UBUNTU_14_10=$?

# Check if upstart exists
command -v initctl > /dev/null
BK_UPSTART_EXISTS=$?

# Check if the system is Amazon linux which has an old and broken upstart.
[ -f /etc/system-release ] && grep -qi "Amazon Linux" /etc/system-release
BK_IS_AMAZON_LINUX=$?

# Install the relevant system process
if [ $BK_SYSTEMD_EXISTS -eq 0 ] && [ $BK_IS_UBUNTU_14_10 -eq 1 ]; then
  if [ ! -f /lib/systemd/system/buildkite-agent.service ]; then
    cp /usr/share/buildkite-agent/systemd/buildkite-agent.service /lib/systemd/system/buildkite-agent.service
  fi

  START_COMMAND="sudo systemctl enable buildkite-agent && sudo systemctl start buildkite-agent"
elif [ $BK_UPSTART_EXISTS -eq 0 ] && [ $BK_IS_AMAZON_LINUX -eq 1 ]; then
  if [ ! -f /etc/init/buildkite-agent.conf ]; then
    # If the system has the old .env file, install the old upstart script, and
    # let them know they should upgrade. Because the upstart script is no
    # longer considered a `config` file in the debian package, when you upgrade
    # the agent, it rm's it from /etc/init, boo. So we need to put it back.
    if [ -f /etc/buildkite-agent/buildkite-agent.env ]; then
      echo "======================= IMPORTANT UPGRADE NOTICE =========================="
      echo ""
      echo "Hey!"
      echo ""
      echo "Sorry to be a pain, but we've deprecated use of the"
      echo "/etc/buildkite-agent/buildkite-agent.env ENV file as a way of configuring the agent."
      echo "It's had some issues and the approach wasn't very cross platform."
      echo ""
      echo "We've switched to using a proper config file that you can find here:"
      echo ""
      echo "/etc/buildkite-agent/buildkite-agent.cfg"
      echo ""
      echo "Everything should continue to work as is (we'll still use the .env file for now)."
      echo "To upgrade, all you need to do is edit the new config file and copy across the settings"
      echo "your .env file, then run:"
      echo ""
      echo "sudo service buildkite-agent stop"
      echo "sudo rm /etc/buildkite-agent/buildkite-agent.env"
      echo "sudo cp /usr/share/buildkite-agent/upstart/buildkite-agent.conf /etc/init/buildkite-agent.conf"
      echo "sudo service buildkite-agent start"
      echo ""
      echo "Then next time you upgrade, you won't see this annoying message :)"
      echo ""
      echo "If you have any questions, feel free to email me at: keith@buildkite.com"
      echo ""
      echo "~ Keith"
      echo ""
      echo "=========================================================================="
      echo ""

      cp /usr/share/buildkite-agent/upstart/buildkite-agent-using-env.conf /etc/init/buildkite-agent.conf
    else
      cp /usr/share/buildkite-agent/upstart/buildkite-agent.conf /etc/init/buildkite-agent.conf
    fi
  fi

  START_COMMAND="sudo service buildkite-agent start"
elif [ -d /etc/init.d ]; then
  if [ ! -f /etc/init.d/buildkite-agent ]; then
    cp /usr/share/buildkite-agent/lsb/buildkite-agent.sh /etc/init.d/buildkite-agent
  fi

  START_COMMAND="sudo /etc/init.d/buildkite-agent start"
else
  # If all the others fails, warn them and just let them run it the old
  # fasioned way.
  echo "============================== WARNING ==================================="
  echo ""
  echo "The Buildkite Agent could not find a suitable system service to install."
  echo "Please open an issue at https://github.com/buildkite/agent and let us know"
  echo ""
  echo "=========================================================================="
  echo ""

  START_COMMAND="sudo /usr/bin/buildkite-agent start"
fi

# Nice welcome message on install
if [ "$OPERATION" = "install" ] ; then
  cat <<"TXT"
 _           _ _     _ _    _ _                                _
| |         (_) |   | | |  (_) |                              | |
| |__  _   _ _| | __| | | ___| |_ ___    __ _  __ _  ___ _ __ | |_
| '_ \| | | | | |/ _` | |/ / | __/ _ \  / _` |/ _` |/ _ \ '_ \| __|
| |_) | |_| | | | (_| |   <| | ||  __/ | (_| | (_| |  __/ | | | |_
|_.__/ \__,_|_|_|\__,_|_|\_\_|\__\___|  \__,_|\__, |\___|_| |_|\__|
                                               __/ |
                                              |___/

TXT

  echo "You now need to add your agent token to \"/etc/buildkite-agent/buildkite-agent.cfg\""
  echo "and then you can start your agent by running \"$START_COMMAND\""
fi

# Crude method of causing all the agents to restart
if [ "$OPERATION" = "upgrade" ] ; then
  # Restart agents that have a process name of "buildkite-agent v1.2.3.4"
  for KILLPID in `ps ax | grep 'buildkite-agent v' | awk ' { print $1;}'`; do
    kill $KILLPID > /dev/null 2>&1 || true
  done

  # Restart agents that have a process name of "buildkite-agent start"
  for KILLPID in `ps ax | grep 'buildkite-agent start' | awk ' { print $1;}'`; do
    kill $KILLPID > /dev/null 2>&1 || true
  done
fi

# Make sure all the the folders created are owned by the buildkite-agent user #
# on install
if [ "$OPERATION" = "install" ] ; then
  if [ "$BK_USER_EXISTS" = "true" ]; then
    # Make sure /etc/buildkite-agent is owned by the user
    chown -R buildkite-agent:buildkite-agent /etc/buildkite-agent

    # Only chown the /var/lib/buildkite-agent folder if it was created
    if [ -d /var/lib/buildkite-agent ]; then
      chown -R buildkite-agent:buildkite-agent /var/lib/buildkite-agent
    fi
  fi
fi

exit 0