deploy.sh

#!/bin/bash
#
# Builds html static pages and deploys them into gh-pages github repo branch.
#
# by Alexander Borsuk <me@alex.bio> from Minsk, Belarus.
#
# Useful debug options:
# -e aborts if any command has failed.
# -u aborts on using unset variable.
# -x prints all executed commands.
# -o pipefail aborts if on any failed pipe operation.
set -euo pipefail

# Publish directory where static html content is generated.
# TODO: Share it between scripts, or use one script with different commands.
OUT_DIR=docs

# Pre-requisites check.
[ -f ./deploy.sh ] || { echo "ERROR: It is not the root repo directory."; exit 1; }
[ -d ./.git ] || { echo "ERROR: It is not a git repository."; exit 1; }
git check-ignore -q $OUT_DIR || { echo "ERROR: Please git rm $OUT_DIR; git commit -a; and add $OUT_DIR to .gitignore."; exit 1; }
# Sanity check.
[[ "$OUT_DIR" != "/" ]] || { echo "Invalid OUT_DIR? $OUT_DIR"; exit 1; }

# Setup cloned git repo in the generated directory.
if [ ! -d "$OUT_DIR/.git" ]; then
  echo "Initializing $OUT_DIR directory and binding it to gh-pages branch of the same repository."
  if [ ! -d "$OUT_DIR"  ]; then
    mkdir "$OUT_DIR"
  else
    rm -rf "$OUT_DIR/*"
  fi
  # Repo should be up-to-date before copying it.
  git remote update
  cp -r .git "$OUT_DIR/.git"
fi

# Initialize and switch to gh-pages branch in the $OUT_DIR/.git repo.
pushd "$OUT_DIR"
# Clear all local changes to avoid pull merge conflicts.
git reset --hard HEAD
git checkout gh-pages > /dev/null 2>&1 && git clean -f && git pull || { git checkout --orphan gh-pages; git rm -rf .; }
popd

# Rebuild everything before deployment.
# Need to save and restore $OUT_DIR/.git directory because generator can delete everything in $OUT_DIR.
mv "$OUT_DIR/.git" .git.backup
source build.sh
mv .git.backup "$OUT_DIR/.git"

# Check if there are any changes to publish.
pushd "$OUT_DIR"
if [[ $(git status --porcelain | wc -l) -eq 0 ]]; then
  echo "There is nothing to publish. Have you made any changes?"
  popd
  exit 0
fi

# Publish web site to Github Pages.
git add -A
git commit -m "Regenerated by deployment script."
git push -u origin gh-pages
popd
echo "Successfully published changes to GitHub Pages."