Convox | Dockerfile

The Dockerfile describes the steps you need to build and run your application.

FROM defines the base image for your application.
COPY moves files from the local directory into the image.
RUN executes a command.
ENTRYPOINT defines a command prefix that should be prepended to any command run on this image.
CMD defines the default command to start application.
ARG allows you to specify build-time variables.

Convox respects the ARG Dockerfile directive, allowing you to specify build-time variables to be populated.

This is useful for creating dynamic build environments, allowing you to do things like:

building differently in production and development environments
specifying environment variables that should be used during a build, but should not be present in the Dockerfile itself or in the resulting image.

You can declare a build argument in the Dockerfile, with either a default value or an empty one:

ARG BUNDLE_WITHOUT="development:test"
ARG RAILS_ENV

You can send a value (or set an empty value, as below) to be applied during remote builds on your Rack by setting it with convox env:

$ convox env set BUNDLE_WITHOUT=none --promote
$ convox deploy

FROM defines the base image for your application.
COPY moves files from the local directory into the image.
RUN executes a command.
ENTRYPOINT defines a command prefix that should be prepended to any command run on this image.
CMD defines the default command to start application.
ARG allows you to specify build-time variables.

Convox respects the ARG Dockerfile directive, allowing you to specify build-time variables to be populated.

This is useful for creating dynamic build environments, allowing you to do things like:

building differently in production and development environments
specifying environment variables that should be used during a build, but should not be present in the Dockerfile itself or in the resulting image.

You can declare a build argument in the Dockerfile, with either a default value or an empty one:

ARG BUNDLE_WITHOUT="development:test"
ARG RAILS_ENV

You can send a value (or set an empty value, as below) to be applied during remote builds on your Rack by setting it with convox env:

$ convox env set BUNDLE_WITHOUT=none --promote
$ convox deploy

See also