#!/bin/bash
#############################################################################
# Purpose:
#   Deploys a tagged version of the code onto the PROD site.
#
# Usage:
#   deploy-drupal-code-prod GIT_RELEASE_TAG_ID
#
# Requirements:
#   1) SSH must have access to an SSH key you've uploaded to the Git server
#      so the code repository can be read.
#   2) Passwordless SSH access (key-based) to the Varnish VMs is necessary to
#      clear the Varnish caches.
#   3) Configure the first section as per your project architecture.
#############################################################################

## Configuration section START ##############################################

# Set log file.
LOGFILE="/var/log/deployments/$(date +%FT%T)"

# Set the Drush site alias for Production.
SITE=@prod

# Set the hostname for the Varnish server.
VARNISH=varnish.prod.example.com

# Set command paths.
DRUSH=/usr/bin/drush
GIT=/usr/bin/git
ECHO=/bin/echo
UMASK=umask

## Configuration section END ################################################

# Fill in some other variables.
WEBDIR=$($DRUSH dd $SITE)
TAG=$1

# Ensure that the script was called appropriately.
if [ "X$TAG" == "X" ]; then
  echo "Usage: $0 <tagname>" 1>&2
  exit 1
fi

# Stop executing the script if any command fails.
# See http://stackoverflow.com/a/4346420/442022 for details.
set -e
set -o pipefail

# Start redirecting output to log file.
{

$ECHO "Setting umask..."
$UMASK 002

$ECHO "Switching to the Web directory..."
cd $WEBDIR

$ECHO "Purging local modifications..."
$GIT reset --hard HEAD

$ECHO "Purging local untracked files..."
$GIT clean -f -d

$ECHO "Grabbing the latest code from the repository..."
$GIT fetch --tags

$ECHO "Switch to appropriate tag (${TAG})..."
$GIT checkout tags/$TAG

$ECHO "Rebuilding the registry in case file locations have changed..."
$DRUSH pm-download registry_rebuild -y
$DRUSH registry-rebuild

$ECHO "Updating the database schema..."
$DRUSH updatedb -y

$ECHO "Reverting all features to those in code..."
# The cache clearing is necessary for https://drupal.org/node/1822278.
$DRUSH cache-clear all
$DRUSH features-revert-all -y

$ECHO "Reverting any views that aren't featurized..."
$DRUSH views-revert --all

$ECHO "Clearing all caches..."
# Drupal.
$DRUSH cache-clear all
# Varnish.
# This will block at a password prompt unless key access has been set up.
ssh $VARNISH varnishadm "ban req.url \~ /"
ssh $VARNISH varnishadm "ban req.url \~ /"

$ECHO "All done!"

} 2>&1 | tee ${LOGFILE}