Bash script to automate the Git Flow tag/release process

release.sh

#!/bin/bash

# current Git branch
branch=$(git symbolic-ref HEAD | sed -e 's,.*/\(.*\),\1,')

# latest version
latestVersion=$(git describe --tags `git rev-list --tags --max-count=1`)

# bump version
bumpVersion=$1

a=( ${latestVersion//./ } )

case $bumpVersion in
major)
  ((a[0]++))
  a[1]=0
  a[2]=0
  ;;
minor)
   ((a[1]++))
  a[2]=0
  ;;
patch)
  ((a[2]++))
  ;;
*)
  echo "Usage: release.sh major|minor|patch"
  exit 1;
esac

versionLabel="${a[0]}.${a[1]}.${a[2]}"

# establish branch and tag name variables
devBranch=develop
masterBranch=master
releaseBranch=release-$versionLabel

# create the release branch from the -develop branch
git checkout -b $releaseBranch $devBranch

# commit version number increment
git commit -am "Incrementing version number to $versionLabel"

# merge release branch with the new version number into master
git checkout $masterBranch
git merge --no-ff $releaseBranch

# create tag for new version from -master
git tag $versionLabel
git push origin

# merge release branch with the new version number back into develop
git checkout $devBranch
git merge --no-ff $releaseBranch

# remove release branch
git branch -d $releaseBranch