Google Cloud Build with pseudo semver

cloudbuild.yaml

steps:
  - name: gcr.io/cloud-builders/git
    args: ["fetch", "--unshallow"]
  - name: gcr.io/cloud-builders/git
    entrypoint: /bin/bash
    args:
      [
        "-c",
        "echo ${_MAJOR}.${_MINOR}.$(git rev-list --count ${BRANCH_NAME}) > ${_VERSION_FILE}",
      ]
  - name: "gcr.io/cloud-builders/docker"
    entrypoint: /bin/bash
    args:
      [
        "-c",
        "docker build --cache-from ${_IMAGE}:latest -t ${_IMAGE}:latest -t ${_IMAGE}:${SHORT_SHA} -t ${_IMAGE}:$(cat ${_VERSION_FILE}) .",
      ]
  - name: gcr.io/cloud-builders/docker
    entrypoint: /bin/bash
    args: ["-c", "docker push ${_IMAGE}:$(cat ${_VERSION_FILE})"]
images: ["${_IMAGE}:latest", "${_IMAGE}:${SHORT_SHA}"]

substitutions:
  _IMAGE: "gcr.io/${PROJECT_ID}/${_REPO_PREFIX}/${_REPO_PROJECT}"
  _VERSION_FILE: "./commits-version.txt"
  # _MAJOR - set in Trigger
  # _MINOR - set in Trigger
  # _REPO_PREFIX - set in Trigger
  # _REPO_PROJECT - set in Trigger

Inspired by https://nieldw.medium.com/get-a-pseudo-sequential-build-number-in-google-cloud-build-85ae591cf86