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Docker Container Options

New

Introduced in 0.3.17

Pass options to Docker during Dokku's build, deploy and run phases

docker-options:add <app> <phase(s)> OPTION    # Add Docker option to app for phase (comma-separated phase list)
docker-options:remove <app> <phase(s)> OPTION # Remove Docker option from app for phase (comma-separated phase list)
docker-options:report [<app>] [<flag>]        # Displays a docker options report for one or more apps

Info

When specifying multiple phases, they must be comma-separated without spaces in between each phase, like so:

dokku docker-options:add node-js-app deploy,run "-v /var/log/node-js-app:/app/logs"

About Dokku phases

Dokku deploys your application in multiple "phases" and the docker-options plugin allows you to pass arguments to their underlying docker container:

  • build: the container that executes the appropriate buildpack
  • deploy: the container that executes your running/deployed application
  • run: the container that executes any arbitrary command via dokku run

Examples

Add Docker options

Add some options for the deployed/running app and when executing dokku run:

# Mount a host volume in a Docker container: "-v /host/path:/container/path"
dokku docker-options:add node-js-app deploy "-v /var/log/node-js-app:/app/logs"
dokku docker-options:add node-js-app run "-v /var/log/node-js-app:/app/logs"

Note

When mounting a host directory in a Dokku app you should first create that directory as user dokku and then mount the directory under /app in the container using docker-options as above. Otherwise the app will lack write permission in the directory.

Remove a Docker option

dokku docker-options:remove node-js-app run "-v /var/log/node-js-app:/app/logs"

Displaying docker-options reports for an app

New

Introduced in 0.8.1

You can get a report about the app's docker-options status using the docker-options:report command:

dokku docker-options:report

=====> node-js-app docker options information
       Docker options build:
       Docker options deploy: -v /var/log/node-js-app:/app/logs
       Docker options run:  -v /var/log/node-js-app:/app/logs
=====> python-sample docker options information
       Docker options build:
       Docker options deploy:
       Docker options run:
=====> ruby-sample docker options information
       Docker options build:
       Docker options deploy:
       Docker options run:

You can run the command for a specific app also.

dokku docker-options:report node-js-app

=====> node-js-app docker options information
       Docker options build:
       Docker options deploy: -v /var/log/node-js-app:/app/logs
       Docker options run:  -v /var/log/node-js-app:/app/logs

You can pass flags which will output only the value of the specific information you want. For example:

dokku docker-options:report node-js-app --docker-options-build

Advanced usage

In your applications folder /home/dokku/app_name create a file called DOCKER_OPTIONS_RUN (or DOCKER_OPTIONS_BUILD or DOCKER_OPTIONS_DEPLOY).

Inside this file list one Docker option per line. For example:

--link container_name:alias
-v /host/path:/container/path
-v /another/container/path

The above example will result in the following options being passed to Docker during dokku run:

--link container_name:alias -v /host/path:/container/path -v /another/container/path

You may also include comments (lines beginning with a #) and blank lines in the DOCKER_OPTIONS file.

More information on Docker options can be found here: https://docs.docker.com/engine/reference/commandline/run/.