Run commands remotely through `git push` - example with 1 level deployment

branch2command.sh

#! /usr/bin/env sh
# This script accepts 1 mandatory argument:
# COMMAND
#
# It's run by git repo hook and current
# workign directory is the bare repo path
#
# Global variables accessible:
# $WORKTREE (points to the working tree)
# 
command=$1

if [ ! $command ]
then
  echo "   ___                  _ "
  echo "  / _ \  ___  _ __  ___| |"
  echo " | | | |/ _ \| '_ \/ __| |"
  echo " | |_| | (_) | |_) \__ \_|"
  echo "  \___/ \___/| .__/|___(_)"
  echo "             |_|         "
  echo "--------------------------------------------"
  echo "--------------------------------------------"
  echo "--------------------------------------------"
  echo " Wrong arguments passed to branch2command.sh"
  echo "--------------------------------------------"
  echo " USAGE: branch2command.sh <command>"
  echo "--------------------------------------------"
  echo "--------------------------------------------"
  echo "--------------------------------------------"
  exit 1
fi

###############################
#### Match command
###############################
case $command in
  # Deploy master branch to nodes
  deploy)
    script="$WORKTREE/deploy.sh"
    if [ -e $script ]
    then
      . $script master
      matched=1
    else
      echo "script could not found"
      exit 1
    fi
  ;;
  rollback)
    git --work-tree=$WORKTREE reset --hard HEAD~
    matched=1
  ;;
esac


######
# END
######
if [ $matched ]
then
   echo " _ .-') _                    .-') _   ('-.   "
  echo "( (  OO) )                  ( OO ) )_(  OO)  "
   echo " \     .'_  .-'),-----. ,--./ ,--,'(,------. "
   echo " ,\`'--..._)( OO'  .-.  '|   \ |  |\ |  .---' "
   echo " |  |  \  '/   |  | |  ||    \|  | )|  |     "
   echo " |  |   ' |\_) |  |\|  ||  .     |/(|  '--.  "
   echo " |  |   / :  \ |  | |  ||  |\    |  |  .--'  "
   echo " |  '--'  /   \`'  '-'  '|  | \   |  |  \`---. "
   echo " \`-------'      \`-----' \`--'  \`--'  \`------' "
  echo "--------------------------------------------"
  echo "--------------------------------------------"
  echo "--------------------------------------------"
  echo " Command was executed. Ignore errors below"
  echo "--------------------------------------------"
  echo "---------------------------------------^----"
  echo "---------------------------------------|----"
  echo "-But verify there are no errors above--|----"
  echo "--------------------------------------------"
  exit 1
fi

pre-receive

#! /usr/bin/env sh
#
# This hook is placed in a Bare repository.
#
# It executes a script inside working tree (so it's part of repo)
# that contains some logic on "what to do" if such "branch name"
# was pushed. If it finds it, it does an action and exits
# So, we actually are using git to run commands remotely from withing
# repo hook which gives our script direct access to the repo for free
#
# Assuming following file structure:
# .
# |-- myproject
# |-- myproject.git
# set WORKTREE=../myproject
#
# Where myproject.git - current bare repo and myproject - working directory
# To enable this hook, rename this file to "pre-receive" and make sure it is executable
#
 
WORKTREE=../myproject

while read oldrev newrev ref
do
  branch=$(echo $ref | awk -F'/' '{print $3}')

  # Convert branch name into a command
  branch2command_script="$WORKTREE/branch2command.sh"
  if [ -e "$branch2command_script" ]
  then
    . $branch2command_script $branch
  fi

  if [ "$branch" != "master" ] && [ "$branch" != "docs" ]
  then
    echo Unrecognized branch name
    exit 1
  fi
done