CICD semantic versioning foo - bump a repository version based on past tags instead of VERSION file

README.md

bump magic

Principal behind this is that I want to automatically bump the semantic version of a repository, but I don't want to manage a VERSION file, as that requires the CICD tool to commit back to master.

A VERSION file can work, but it has several limitations

• we can't properly configure branch protection if the CICD tool needs to push directly to master
• we have to pull in between each version bump
• the CICD list of jobs fills up with [skip ci] bump version entries
• there is a risk of bump conflict if person A pushes, and then person B pushes before the bump is complete.

This example is for CircleCI (note a read/write deploy key is required), but it should work just as easily for Gitlab, Jenkins etc.

The main magic happens with this line

        @(git tag --sort=-creatordate | grep -E '^\d+\.\d+\.\d+$$' || echo '0.0.0') | head -n 1 > VERSION

it will list all tags sorted by their creatordate, latest to oldest, from that we can grep for whatever regex we want - if nothing is found (e.g. in a new repo), then we output the starting version number 0.0.0 and put it in a version file which the bump tool will parse.

thanks go to @treeder for the very nice and simple bump tool - https://github.com/treeder/dockers/tree/master/bump

circleci.yml

# .config/circleci.yml

version: 2
jobs:
  test:
    ... do stuff
    
  bump:
    docker:
      # use a very simple version bump tool, from
      # https://github.com/treeder/dockers/tree/master/bump
      - image: treeder/bump:1.2.8
    working_directory: ~/repo
    steps:
      - checkout
      - setup_remote_docker
      - add_ssh_keys:
          fingerprints:
            - "blah:blah:blah"
      - run:
          name: install pre-requisites
          command: apk --no-cache add git make openssh-client
      # may or may not be necessary - checkme
      #- run:
      #    name: skip StrictHostKeyChecking for github
      #    command: echo -e "Host github.com\n\tStrictHostKeyChecking no\n" >> ~/.ssh/config
      - run:
          name: bump the version
          command: make bump
          
  build:
    ...
    
  release:
    ...

workflows:
  version: 2
  build:
    jobs:
      - build
      - bump:
          requires:
            - build
          filters:
            branches:
              only: master
            tags:
              ignore: /.*/

  release:
    jobs:
      - release:
          filters:
            branches:
              ignore: /.*/
            tags:
              only: /^\d+\.\d+\.\d+$/

Makefile

.PHONY: bump

# version bump, assumes we're in treeder/bump in CircleCI
bump:
	@git config --global user.email "-"
	@git config --global user.name "CircleCi"
	@(git tag --sort=-creatordate | grep -E '^\d+\.\d+\.\d+$$' || echo '0.0.0') | head -n 1 > VERSION
	@/script/bump $$(git log -1 --pretty=%B)
	@git tag $$(cat VERSION)
	@git push origin $$(cat VERSION)