docker_builder.md

Docker builder

When building a Docker image, you are by default now allowed to reference different locations in a file system. This can be very problematic if you a re building an application with several custom dependencies in private repos. symphony.DockerBuilder provides a easy solution to this problem.

Settings

Each docker build contains a setting. Here is an example in yaml format.

temp_directory: ~/symph_temp/cpu
verbose: true # (prints docker cmdline output)
dockerfile: ~/surreal/Surreal/container/DockerfileCPU
context_directories: # These paths will be copied to temp_directory before build
  - name: surreal # Directory will be under folder @name in the build context
    path: ~/surreal/Surreal
    force_update: true # Copy a new version every time
  - name: mjkey.txt
    path: ~/.mujoco/mjkey.txt
    force_update: false

• temp_directory is the location where we construct the build context for docker. To ensure we don't accidentally include a lot of file, the docker builder will create a sub-folder where docker build is run in.
• verbose controls how much output is showed. It is True by default.
• dockerfile points to the dockerfile of the build
• context_directories is a list of dictionaries. Specifying what files or directories to fetch for the build process.
• Each dictionary in the context_directories list has three attributes:
  • name: What the name of the file or directories in the build context.
  • path: Where to copy from. If it is a file, it is moved to name in the build folder. If it is a directory, the entire tree is copied.
  • force_update: If the file or directory already exists in the build context (e.g. from the last build), force_update=True will remove the existing files and copy from the file system again. force_update=False will use the cached versions. This is used to help speed up the build process when there are several custom libraries but only one is being actively worked on.

Using the docker builder

You can load the settings in a dictionary and use it to initialize the docker builder. This builder can then build, tag and push the image.

from symphony import DockerBuilder

dockerfile = '~/surreal/symphony/test/test_docker_Dockerfile'
context_directories = [
    {
        'name': 'surreal',
        'path': '~/surreal/Surreal',
        'force_update': False,
    },
    {
        'name': 'tensorplex',
        'path': '~/surreal/Tensorplex',
        'force_update': True,
    }
]
temp_directory = '~/symph_tmp/'
repo = 'my_repo'
tag = 'latest'

builder = DockerBuilder(dockerfile, context_directories, temp_directory, verbose=True)

builder.build()

builder.tag(repo, tag)

builder.push(repo, tag)