Dockerfile Instructions

The Dockerfile manifest specifies how a Docker image is to be built. For all configuration options, see the official Dockerfile documentation. The Dockerfile manifest is specified in the images configuration hash using the manifest option. Cloudpad looks for a manifest in the manifests directory with the file name of <name>.dockerfile.

By default, the manifest is an ERB file, meaning you can use ERB ruby tags to include Cloudpad configuration parameters. In order to reduce redundancy, Cloudpad includes a ERB-available command to run ruby commands directly within your dockerfile as it's being compiled to output dynamic commands.

Usage

The command takes the format of:

<%= dfi :command, [arg-1], [arg-n] %>

Or in a larger example:

# vi:syntax=dockerfile

FROM phusion/baseimage:0.9.12
MAINTAINER Alan G. Graham "alan@productlab.com"

### PRIMARY PACKAGES

RUN apt-get update -q

<%= dfi :install_haproxy_153 %>

### ADDITIONAL PACKAGES

RUN apt-get install -qy git-core

<%= dfi :run, 'bin/setup_box.py', '--core' %>

### APP STUFF

ENV RACK_ENV <%= fetch(:stage) %>

### SERVICES

ADD conf/haproxy.conf.tmpl /root/conf/haproxy.conf.tmpl

### CONTAINER STUFF

ADD bin /root/bin

RUN echo "<%= container_public_key %>" >> /root/.ssh/authorized_keys

EXPOSE 80

CMD ["/sbin/my_init"]

<%= dfi :install_image_services %>

Pre-defined Instructions

Cloudpad comes with a few pre-defined dockerfile instructions.

• install_image_gemfiles - Installs the cache Gemfiles in conf for all the specified image repos.
• install_image_repos - Installs the source code for all the specified image repos.
• install_image_services - Installs available_services and activates services.
• run - [script, args*] Adds and runs the script located in the context.

Custom Instructions

To add your own DFI helper commands, you set the global option dockerfile_helpers with a hash of command blocks:

set :dockerfile_helpers, {
	install_ruby_200: lambda {
		# do logic here
		# must end with a string that adds command to manifest
		# Don't forget newlines for multiple commands
		"RUN string with command..."
	}
}