Deploy a Jekyll site to a non-bare repository via git push

jekyll-git-push.sh

#!/bin/bash

#
# Utility script which can be used to trigger rebuild of a jekyll site that is
# managed via a git repository.  Most often, you would call this script in the
# post-receive hook of a full (non-bare) git repository, such that the rebuild
# happens after a push.
#
# Run with no arguments for usage.
#
# CAVEATS:
#
# 1. The git, jekyll, and pygmentize executables must be in the PATH.
# 2. receive.denycurrentbranch should be set to 'warn' or 'ignore' in the
#    target repository. From within the target repository:
#      git config receive.denycurrentbranch warn
# 3. If you're foolish enough leave uncommitted changes lying around in the
#    target repository, this script will wipe them out!
#

# Source the .bashrc file if present, this allows for a non-standard location
# of executables, such as via RVM/pyenv.
if [ -f ~/.bashrc ]; then
  . ~/.bashrc
fi

GIT=`which git`
JEKYLL=`which jekyll`
TIMESTAMP=`date`

REPO_DIR=$1
LOG_FILE=$2

function usage() {
  echo "
Usage: jekyll-git-push.sh <repo_dir> [log_file]

  repo_dir: Full path to the working tree of the jekyll site repository.
  log_file: Optional file to log results to.

  Ex. jekyll-git-push.sh /home/me/repo /tmp/jekyll.log

"
}

function log() {
  message=$1
  log_message="$TIMESTAMP - $REPO_DIR - $message"
  echo "$log_message"
  if [ "$LOG_FILE" != "" ]; then
    echo "$log_message" >> $LOG_FILE
  fi
}

if [ "$REPO_DIR" = "" ]; then
  log "ERROR: no repository configured"
  usage
  exit 1
fi

$GIT --work-tree=${REPO_DIR} --git-dir=${REPO_DIR}/.git reset --hard
if [ $? = 0 ]; then
  $JEKYLL build -s $REPO_DIR -d ${REPO_DIR}/_site
  if [ $? = 0 ]; then
    log "site rebuild successful"
    exit 0
  else
    log "ERROR: could not rebuild site"
    usage
  fi
else
  log "ERROR: could not reset the git working tree"
  usage
fi

exit 1