Docker Compose Override

docker_compose_override

Generates a supplementary docker-compose.yml file, utilized for some of the more advanced just features.

Arguments:: See docker_compose_override generate_docker_compose_override

Note

docker_compose_override can be sourced so that individual functions can be called

See also

docker_compose_override generate_docker_compose_override: The main docker compose override function

_docker_compose_override_var_sub string

Arguments:

1 - String of variable name, such as '${var}'

Output:

stdout - Variable name

Internal Use:

Yes

Unwraps a bash style basic variables name in a string. Assumes the string is a variable expression, so the first letter is assumed to be a $, and is not checked

Example

indirect=$(_docker_compose_override_var_sub '${foo}')
# indirect=var
indirect=$(_docker_compose_override_var_sub '$bar')
# indirect=bar

Deprecated since version 0.0.4.

_env_echo

Arguments:

[1 …] - arguments to echo

Output:

stdout - Yaml excerpt * new_environment - Value is “1” if _env_echo has been called already

Simple helper function for echoing environment variables in the docker-compose.yml file

In docker compose, the environment: section can only be added once, and can only be added if there is at least one environment variable set. In case there are none, nothing should be added. This helper only echoes environment: the first time it is called.

generate_docker_compose_override

Arguments:

1 - Prefix used in many of the just features, such as ${1}_.*_DOCKER/HOST variables, etc…
[2 …] - List of services to process (see docker_compose_service_names)

Output:

stdout - The docker compose override yaml file

Create a docker override yaml file and extend the current docker compose configuration with:

Volume features:
- Volumes can be added to the services listed in $2…
  - Volumes listed in ${1}_VOLUMES are added to every service
  - Volumes in ${1}_VOLUME_1, ${1}_VOLUME_2, … are added to every service
  - Volumes listed in ${1}_<upper(service_name)>_VOLUMES are added only to that service.
  - Volumes listed in ${1}_<upper(service_name)>_VOLUME_1, ${1}_<upper(service_name)>_VOLUME_2, … are added only to that service.
  - Note: If the yaml file uses anchors, this will not be reflected in this auto generated file. You will have to set the value of ${1}_<upper(other_service_name)>_VOLUMES as well
Environment features:
- For volumes that couldn’t be mounted in their expected locations (mostly due to nfs limitations), the variable JUST_DOCKER_ENTRYPOINT_LINKS is set to a colon delimited string (used by docker_entrypoints.bsh/docker_link_mounts).
- Keep a // separated list of docker data volumes in JUST_DOCKER_ENTRYPOINT_INTERNAL_VOLUMES.
- Environment variables ${1}_.*_HOST are added to the docker environment exactly as is.
- Transparently swap environment variables as they are added to the docker environment (default):
  - For every environment variable, ${1}_.*_DOCKER, and optionally its corresponding un-suffix’ed version ${1}_.*
    - ${1}_.* variable is copied as ${1}_.*_HOST
    - ${1}_.*_DOCKER variable is copied as ${1}_.*
    - VIP_FOO=/opt/foo is copied to VIP_FOO_HOST=/opt/foo and VIP_FOO_DOCKER=/foo is copied to VIP_FOO=/foo
  - This is a transparency feature. Only _DOCKER variables should use the _DOCKER suffix.
- The transparency swap feature can be disabled by setting JUST_DISABLE_ENVIRONMENT_SWAP=1. In which case:
  - For every environment variable ${1}_.*_DOCKER
    - ${1}_.*_DOCKER is copied exactly as is
    - ${1}_.* is copied exactly as is if it exists
NVIDIA GPU features:
- NVIDIA GPU support can be added to the services listed in $2…
  - GPU support in docker compose is specified in https://docs.docker.com/compose/gpu-support/
  - ${1}_NVIDIA_VISIBLE_DEVICES a space or comma delimited string controls which GPUs are mounted into the container
    - GPU index ordering is as reported by nvidia-smi --list-gpus
    - An empty or unset ${1}_NVIDIA_VISIBLE_DEVICES results in no GPU support
    - A list of available indices can be obtained using nvidia_tools.bsh nvidia_device_indices
  - ${1}_NVIDIA_DRIVER_CAPABILITIES a space or comma delimited string controls which driver libraries/binaries will be mounted inside the container
    - Driver capabilities default to gpu as per the docker compose specification
    - https://docs.nvidia.com/datacenter/cloud-native/container-toolkit/user-guide.html#driver-capabilities

COMPOSE_VERSION

Default:: Unset. Version tag will not be added to compose file.
Optional:: True

Docker compose version used.

JUST_DISABLE_ENVIRONMENT_SWAP

Default:: 0
Optional:: True

Disables the transparent variable swap feature.

EXPORT_DOCKER

Default:: 0
Optional:: True

Also exports the ${1}_.*_DOCKER version of the variable when using the transparent environment variable swap feature (the swap effectively becomes a copy).

MOUNT_PREFIX

Default:: /host_mnt
Optional:: True

Some mounted file systems will not allow subdirectories to be mounted by root, such as nfs with squash root turned on. In this case, generate_docker_compose_override will mount the root of an nfs mount point in a secondary location, and then symlink the subdirectory to its original mount point. This may be slightly less than ideal, but this is the best that can be done with these file systems. The MOUNT_PREFIX is the secondary location where these mount points are mounted. Apps running in a container should use the expected mount point, not these secondary mount points.

DOCKER_COMPOSE_FILES

Default:: ()
Optional:: True

Array of docker compose yaml files to parse for volumes

Note

There is no way to use the _VOLUMES features from the CLI, as arrays cannot be exported. However the _VOLUME_1 feature will work