This guide describes how to build a docker image and publish the docker image to AWS Elastic Container Registry (AWS ECR). ECR is a service to host private Docker images in AWS.
- This guides assumes that there is a
Dockerfilein the root folder of the project
- An AWS account
- An AWS user with programmatic access. Remember to note down the access key and the secret for the user
- An Azure DevOps project
Step 1: Create an AWS ECS Repository
Go to the ECR service in AWS and create a new repository. Remember to note the repository url. The repository url will consist of your account number, region, AWS ECR service url and your repository name. E.g:
Step 2: Create the Azure DevOps Pipeline Build File
By storing the Azure DevOps Pipeline configuration one can have versions control of the build pipeline. That makes it a lot easier to spot errors and changes to the build pipeline. Create a new file called
build-pipline.yml. In the steps below the contents of the build file are explained.
Triggers are used to tell Azure DevOps when the build pipeline should run. The snippet below defines that the pipeline should run each time the master branch gets new changes.
trigger: branches: include: - master
The following lines tells the pipeline to pick the latest available Ubuntu image as the VM image.
pool: vmImage: 'ubuntu-latest'
Variables should not be stored in the build file. This can be avoided by storing the variables and secrets in a library, which can be found at
Piplines -> Library. The following variables are needed for this guide to work:
The variables are made available by adding the group name. In this example the group is called
dev. Additionally one inline variable named
DOCKER_REPOSITORY is defined, which stores the docker repository url.
variables: - group: dev - name: DOCKER_REPOSITORY value: $(AWS_ACCOUNT_ID).dkr.ecr.$(AWS_REGION).amazonaws.com/$(DOCKER_REPOSITORY_NAME)
The Docker registry requires authentication before any images can be pushed. Authentication can be done using a bash script. The AWS CLI is available by default. It is not possible login directly into AWS ECR using the Docker CLI. Authentication is done using a one time password obtained running the AWS ECR CLI command
get-login-password. The ECR command uses the API keys to authenticate. After obtaining the one time password, the password is piped into the Docker CLI command. Logging in to the registry can then be done with a user named
AWS and with the one time password piped from the previous step. The option
--password-stdin is needed for the command to pickup the password. The Docker registry url is added at the end of the login command.
steps: - script: | aws ecr get-login-password --region $(AWS_REGION) | docker login --username AWS --password-stdin $(AWS_ACCOUNT_ID).dkr.ecr.$(AWS_REGION).amazonaws.com displayName: 'Login to AWS' env: AWS_ACCESS_KEY_ID: $(AWS_ACCESS_KEY_ID) AWS_SECRET_ACCESS_KEY: $(AWS_SECRET_ACCESS_KEY)
Docker Build and Push
Azure DevOps has a built in task for Docker which can be used to build and push the image in one task. The Docker task requires a few inputs to work:
repository- the repository url for the image
buildAndPushis the combined command to use to build and push in one task
Dockerfile- add the location of the Dockerfile
tags- an array of the tags
- task: Docker@2 displayName: Build docker image inputs: repository: $(DOCKER_REPOSITORY) command: buildAndPush Dockerfile: Dockerfile tags: | latest
trigger: branches: include: - master pool: vmImage: 'ubuntu-latest' variables: - group: dev - name: DOCKER_REPOSITORY value: $(AWS_ACCOUNT_ID).dkr.ecr.$(AWS_REGION).amazonaws.com/$(DOCKER_REPOSITORY_NAME) steps: - script: | aws ecr get-login-password --region $(AWS_REGION) | docker login --username AWS --password-stdin $(AWS_ACCOUNT_ID).dkr.ecr.$(AWS_REGION).amazonaws.com displayName: 'Login to AWS' env: AWS_ACCESS_KEY_ID: $(AWS_ACCESS_KEY_ID) AWS_SECRET_ACCESS_KEY: $(AWS_SECRET_ACCESS_KEY) - task: Docker@2 displayName: Build docker image inputs: repository: $(DOCKER_REPOSITORY) command: buildAndPush Dockerfile: Dockerfile tags: | latest
Step 3: Create a Pipline in Azure DevOps
Go to the
Piplines tab in Azure DevOps and create a new pipeline. If the code is hosted in Azure DevOps select
Azure Repos Git and select the git repository in the next step. Under the
Confgure your pipeline step, select the option
Existing Azure Pipelines YAML file. Then choose the git branch and the location of the pipeline config file created in the beginning of this guide. In the
Review step click save to publish the pipeline.
You are now all setup! The pipeline should build and deploy your Docker image each time you push new code to the master branch in your git repository.
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