Docker


Prerequisites A `Dockerfile` that defines the Docker image is stored in the project sources. Eligible images Not required. A `docker` step runs in a special custom image.

Prerequisites

A Dockerfile that defines the Docker image is stored in the project sources.

Eligible images

Not required. A docker step runs in a special custom image.

We suppose two main CI/CD scenarios for Docker:

Automated Docker builds: All image dependencies already exist and all you need is to build and publish a Docker image.
Creating dependencies before the build: An Automation job must create image dependencies before building and publishing the image.

Space Automation DSL provides a special docker keyword that simplifies working with Docker builds.

Build and publish a Docker image

For example, the job below first builds and then publishes the image defined in the Dockerfile located in the project's docker directory.

            job("Build and push Docker") {
                docker {
                    build {
                        context = "docker"
                        file = "./docker/Dockerfile"
                        args["HTTP_PROXY"] = "http://10.20.30.2:1234"
                        labels["vendor"] = "mycompany"
                    }

                    push("mycompany.registry.jetbrains.space/p/projectkey/mydocker/myimage") {
                        // use current job run number as a tag - '0.0.run_number'
                        tag = "0.0.\$JB_SPACE_EXECUTION_NUMBER"
                        // see [[[example|https://www.jetbrains.com/help/space/automation-environment-variables.html#example]]] on how to use branch name in a tag
                    }
                }
            }
        

docker: is a special step used to build and publish Docker images. In fact, it's a special type of container with Docker on board.
build: runs the docker build command with the following arguments
- context: a path to Docker context (by default, it's a working directory ). The build process can refer to any of the files in the context.
- file: a path to Dockerfile.
- args: sets build-time variables.
- labels: sets labels for the image.
push: runs the docker push command with the following arguments
- "mycompany.registry.jetbrains.space/mydocker/myimage": image name including the repository URL. Note that to be able to push to a Space Packages Container registry, your script doesn't require authentication.
- tag: specifies the image tag.

Create an image dependency, build, and publish a Docker image

Quite often, you may need to first generate some artifact (say, a .jar file) and then put it into an image. Such cases require running two steps: The first generates the artifact and the second one runs docker build and docker push.

            job("Build and push Docker") {
                container(displayName = "Run gradle build", image = "openjdk") {
                    shellScript {
                        content = """
                                ./gradlew build
                                cp output mnt/space/share
                            """
                    }
                }

                docker {
                    resources {
                        cpu = 1.cpu
                        memory = 2000.mb
                    }
                    beforeBuildScript {
                        content = "cp mnt/space/share docker"
                    }
                    build {
                        context = "docker"
                    }
                    push("mycompany.registry.jetbrains.space/mydocker/myimage") {
                        tag = "0.\$JB_SPACE_EXECUTION_NUMBER"
                    }
                }
            }
        

The container step uses gradlew build to generate some artifacts and put them to the file share.
In the docker step:
- resources specifies system resources as in a regular container.
- beforeBuildScript is a sub-step that runs before build. Here we use beforeBuildScript to copy the Gradle output from the file share to the context directory.
- build and push build and push the image correspondingly.

Last modified: 16 April 2021