minimal build version tracking

bump.sh

#!/bin/bash

# This is a simple script that increments the integer in a the 'build-version'
# file, and makes a new commit. The new commit will be tagged with the branch
# and version
#
# You may specify a path. If no path is specified, the working directory will be
# used.
#
# Eventually we might want to replace this with a proper CI pipline, but this
# is a reasonable placeholder for now.

# check if the user supplied a path to cd into
if [ $# -eq 0 ]
then
    echo "No argument supplied. using current dir: `pwd`"
else
    cd $1 || exit 1
fi

# Check if git working dir is clean
#
# We do not want to proceed if there are changes, because we will add and commit
# the new build-version file.
if [[ `git status --porcelain` ]] # double braces ok in bash, may not work in sh
then
    echo "Working dir is not clean. Aborting."
    exit 1
fi

# ensure that the build-version file exists
if [ ! -e build-version ]
then
    echo "Creating build-version file"
    echo "0" > build-version
    git add build-version
fi

# Get the current version from the file
V=$(head -1 build-version)

# Validate build-version
if [ "$V" ! -eq "$V" ] 2>/dev/null
then
    echo "Previous version: $V"
    echo "Previous version must be an integer"
    exit 1
fi

# Increment build-version
V_NEXT=$(($V + 1))
echo "Updated ver: $V_NEXT"
echo $V_NEXT > build-version

# Build that updated tag name.
BRANCH=$(git symbolic-ref --short -q HEAD)
TAG="$BRANCH-v$V_NEXT"
echo "Updated tag: $TAG"
echo

# commit the updated build-version
echo "Committing and tagging..."
git add build-version
git commit -m "Update build version to $V_NEXT" || exit 1
git tag $TAG