Docker Build & Push Action

Builds a Docker image and pushes it to the private registry of your choosing.

Basic usage

• Ensure you run the checkout action before using this action
• Add the following to a workflow .yml file in the /.github directory of your repo

steps:
  - uses: actions/checkout@v1.0

  - uses: mr-smithers-excellent/docker-build-push@v2
    with:
      image: repo/image
      tag: latest
      registry: registry-url.io
      dockerfile: Dockerfile.ci
      username: ${{ secrets.DOCKER_USERNAME }}
      password: ${{ secrets.DOCKER_PASSWORD }}

Inputs

Name	Description	Required
image	Docker image name	Yes
tag	Docker image tag (see Tagging the image with GitOps)	No
registry	Docker registry host	Yes
dockerfile	Location of Dockerfile (defaults to Dockerfile)	No
buildArgs	Docker build arguments in format KEY=VALUE,KEY=VALUE	No
username	Docker registry username	No
password	Docker registry password or token	No

Examples

Docker Hub

• Save your Docker Hub username (DOCKER_USERNAME) and password (DOCKER_PASSWORD) as secrets in your GitHub repo
• Modify sample below and include in your workflow .github/workflows/*.yml file

uses: mr-smithers-excellent/docker-build-push@v2
with:
  image: docker-hub-repo/image-name
  registry: docker.io
  username: ${{ secrets.DOCKER_USERNAME }}
  password: ${{ secrets.DOCKER_PASSWORD }}

Google Container Registry (GCR)

• Create a service account with the ability to push to GCR (see configuring access control)
• Create and download JSON key for new service account
• Save content of .json file as a secret called DOCKER_PASSWORD in your GitHub repo
• Modify sample below and include in your workflow .github/workflows/*.yml file
• Ensure you set the username to _json_key

uses: mr-smithers-excellent/docker-build-push@v2
with:
  image: gcp-project/image-name
  registry: gcr.io
  username: _json_key 
  password: ${{ secrets.DOCKER_PASSWORD }} 

AWS Elastic Container Registry (ECR)

• Create an IAM user with the ability to push to ECR (see example policies)
• Create and download access keys
• Save AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY as secrets in your GitHub repo
• Modify sample below and include in your workflow .github/workflows/*.yml file

uses: mr-smithers-excellent/docker-build-push@v2
with:
  image: image-name
  registry: [aws-account-number].dkr.ecr.[region].amazonaws.com
env:
  AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
  AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}

Tagging the image using GitOps

By default, if you do not pass a tag input this action will use an algorithm based on the state of your git repo to determine the Docker image tag. This is designed to enable developers to more easily use GitOps in their CI/CD pipelines. Below is a table detailing how the GitHub trigger (branch or tag) determines the Docker tag.

Trigger	Commit SHA	Docker Tag
/refs/tags/v1.0	N/A	v1.0
/refs/heads/master	1234567	dev-1234567
/refs/heads/SOME-feature	1234567	some-feature-1234567