Crib Sheet: Important Docker commands

Start the Docker deamon on your machine (ECMWF):

which is actually:    sudo /usr/bin/systemctl status docker

Which images are on my machine:

Which containers are running:

Build docker image:

At ECMWF:    docker build -t oifs --build-arg http_proxy="$http_proxy" --build-arg ftp_proxy="$ftp_proxy" --build-arg https_proxy="$https_proxy" --build-arg no_proxy="$no_proxy" .

Run docker images in container:

Use Harbor online container registry:

Do this first:   docker login eccr.ecmwf.int

The build command below makes an image that can be pushed to harbor:   docker build -t eccr.ecmwf.int/openifs/oifs:0.0.1 -f --build-arg http_proxy="$http_proxy" --build-arg ftp_proxy="$ftp_proxy" --build-arg https_proxy="$https_proxy" --build-arg no_proxy="$no_proxy"

Then push it to harbor, manually specifying version number.  Careful: Existing version numbers are overwritten!     docker push eccr.ecmwf.int/openifs/oifs:0.0.1

Pull image from repository into memory:    docker pull eccr.ecmwf.int/openifs/oifs:0.0.1

Dockerfiles

The Dockerfile describe the build process for the Docker image. Examples for several of these files are provided in the OpenIFS git repository.

The naming convention for Dockerfiles is as such:

Example:    Dockerfile.oifs40r1v2.41537.user.x86_64.bld

Example Build Process

The following describes the build process of a container image from the Dockerfile. You need the following files in your build directory:

The Dockerfile can be obtained from the git repository. As described through the naming convention it will generate an image of OpenIFS 40r1 version 2. The partial git hash relates the Dockerfile (and image) to a specific git commit in the OpenIFS repository (in this case it relates to 415374d which is tagged as model release v2 ). The note 'root' indicates that when the image is loaded as a container the user will have root privileges. This will allow us to explore the directory structure of the container image. For convenience it is recommended to create a symbolic link to the generic name Dockerfile.

The tar archive oifs40r1v2.41537.tar.gz is created from the model sources after they have been checked out from the git repository (again the partial commit is specified). The Dockerfile will expect the tar archive in the same directory and the file name is specified.

The following command builds the image oifs40r1v2.415374d.root. The generic command is  docker build -t <image_name>  however at ECMWF four variables need to be set for network proxies in order to access the internet from within the container.

This starts the generation process of the image which contains the minimum of software that is required to run OpenIFS. The image is based on a Ubuntu Linux LTS version and in a first step the necessary developer tools are installed (e.g. GNU compiler, MPI and maths libraries). Afterwards the ecCodes library is obtained via download from the web and compiled with minimum settings. Then the OpenIFS sources are added from the tar archive, required environment variables are set and the model binaries are compiled. During a last step various file permissions are set and the model executable is moved to a globally accessible location.

At the end of the build process the successful image creation is shown as: 
Successfully tagged oifs40r1v2.415374d.root:latest

Now we can verify the that the image is available and load it into a container:

Our command line prompt has changed as we are now 'root' inside the container. With the command 'exit' the container is removed and all file changes in the container are lost. A file listing shows the directory structure inside the container. The OpenIFS model is installed in /oifs.