> For the complete documentation index, see [llms.txt](https://docs.duplocloud.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.duplocloud.com/docs/automation-platform/introduction-to-ci-cd/gitlab-ci-cd/build-a-docker-image.md). # Build a Docker image ## Case: Build and Push to DockerHub The goal of this section is to show how you can build a docker image and push it to DockerHub. It does three basic things: * Logs in to DockerHub * Builds and tags your docker image, with the tag based on the git commit SHA. * Pushes your docker image ### Example Workflow Here is an example gitlab workflow that builds a docker image and pushes it to DockerHub. To use it you will need to change: * `DOCKERHUB_USERNAME`variable * `DOCKERHUB_REPO`variable * `DUPLO_HOST`variable * `DUPLO_SERVICE_NAME`variable * `TENANT_NAME`variable ```yaml variables: DOCKERHUB_USERNAME: duplocloud # CHANGE ME! DOCKERHUB_REPO: mydockerhubid/myrepo # CHANGE ME! DUPLO_HOST: https://mysystem.duplocloud.net # CHANGE ME! DUPLO_SERVICE_NAME: myservice # CHANGE ME! TENANT_NAME: mytenant # CHANGE ME! docker-build: # Use the official docker image. image: docker:latest stage: build services: - docker:dind before_script: - docker login -u "$DOCKERHUB_USERNAME" -p "$DOCKERHUB_PASSWORD" script: - | tag=":$CI_COMMIT_SHA" echo "Running on branch '$CI_COMMIT_BRANCH': tag = $tag" - docker build --pull -t "$DOCKERHUB_REPO${tag}" . - docker push "$DOCKERHUB_REPO${tag}" # Run this job in a branch where a Dockerfile exists rules: - if: $CI_COMMIT_BRANCH exists: - Dockerfile ``` ## Case: Build and Push to Amazon ECR (Elastic Container Registry) The goal of this section is to show how you can build a docker image and push it to Amazon ECR. It does three basic things: * Logs in to Amazon ECR * Builds and tags your docker image, with the tag based on the GitLab CI Pipeline execution id. * Pushes your docker image to ECR *Prerequisite - A repository in ECR must have been created before proceeding with the next steps.* This process uses DuploCloud API Token (refer [DuploCloud API Token](https://docs.duplocloud.com/docs/administrators/access-control/api-tokens#permanent-api-tokens)) to gain access to AWS ECR. Go to GitLab > Settings > CI CD > Variables > Expand and ensure that DUPLO\_TOKEN variable is set and has correct value. Check the Protect Variable and Masked options for security purposes. You can refer to [Configuring GitLab](https://docs.duplocloud.com/docs/ci-cd/github-actions-1/configuring-github) for the steps to setup a service account and to create a token for the newly configured account. The service account must have admin role. The script uses amazon/aws-cli image as the base running image and uses Docker-in-Docker (docker/dind) to run the Docker commands. It uses duplo\_utils.sh script from DuploCloud to get configuration from the DuploCloud instance. ### Example Workflow Here is an example gitlab workflow that builds a docker image and pushes it to DockerHub. To use it you will need to change: * `DOCKER_REGISTRY`variable * `DOCKER_REPO` variable * `DUPLO_HOST` variable * `DUPLO_SERVICE_NAME` variable * `TENANT_NAME` variable * `AWS_DEFAULT_REGION`variable * `APP_NAME`variable ```yaml variables: DOCKER_REGISTRY: .dkr.ecr..amazonaws.com DOCKER_REPO: .dkr.ecr..amazonaws.com/xxx-yyy AWS_DEFAULT_REGION: AWS_ECR_REGION: APP_NAME: DUPLO_HOST: https://.duplocloud.net DUPLO_SERVICE_NAME: TENANT_NAME: DOCKER_HOST: tcp://docker:2375 stages: - build - deploy build-and-push-job: stage: build image: name: amazon/aws-cli entrypoint: [""] services: - docker:dind before_script: - yum install -y wget jq - amazon-linux-extras install docker - wget https://raw.githubusercontent.com/duplocloud/demo-npm-service/master/.circleci/duplo_utils.sh - chmod +x duplo_utils.sh - source duplo_utils.sh - with_aws>tmp.txt #Get secrets using with_aws script from source duplo_utils.sh - cat tmp.txt - cat tmp.txt|grep -i AWS_>tmp1.txt - cat tmp1.txt - source tmp1.txt - export $(cut -d= -f1 tmp1.txt) - aws ecr get-login-password --region $AWS_ECR_REGION | docker login --username AWS --password-stdin $DOCKER_REGISTRY - rm tmp.txt tmp1.txt #remove the secrets from the runner script: - | tag="$CI_PIPELINE_IID" echo "Running on branch '$CI_COMMIT_BRANCH': tag = $tag" - docker build -t "$DOCKER_REGISTRY/$APP_NAME:${tag}" ./nginx/ - docker push "$DOCKER_REGISTRY/$APP_NAME:${tag}" - docker logout #For security ``` --- # Agent Instructions This documentation is published with GitBook. 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