post-recieve hook to automatically deploy a git branch to either staging or production. (or do nothing)

post-receive

#!/bin/bash
# git/hooks/post-receive
# add this script to a git repo on a 'remote' server 
# to automatically deploy a git branch to either staging or production (or do nothing)

WORK_TREE_PROD=$HOME/production  # assumes logged in user HOME/production path is webroot
WORK_TREE_STAGE=$HOME/staging    # assumes logged in user HOME/staging    path is webroot
GIT_DIR=$HOME/git                # assumes remote git repo is in HOME/git  (no dot - not hidden)


# The post-receive hook can receive multiple branches at once (for example if someone does a git push --all), so we also need to wrap the read in a while loop.
while read oldrev newrev ref
do
    branch=`echo $ref | cut -d/ -f3`
    case $branch in
      "production")
          echo "Production ref received.  Deploying production branch to $WORK_TREE_PROD ..."
          [ -d "$WORK_TREE_PROD" ] && git --work-tree="$WORK_TREE_PROD" checkout -f && echo "success"  
        ;;
      "master")
          echo "Master ref received.  Deploying staging branch to $WORK_TREE_STAGE ..."
          [ -d "$WORK_TREE_STAGE" ] && git --work-tree="$WORK_TREE_STAGE" checkout -f && echo "success"
        ;;
      "")
        echo "Branch (=${branch}) is empty.  hmm.  that ain't right.  time to debug"
        ;;
      *)
        echo "Ref $branch successfully received.  Nothing to do since only the production branch may be deployed on this server."
        ;;
    esac
done