Two-Phase Deployment for Capistrano 3.1

This gem provides two-phase deployment capabilities to capistrano 3.

The deployment process is split into two phases: the first generates a tar.gz file of the content to be deployed via cap deploy:prepare_release and uploads it to an intermediary server. This intermediary server should ideally be located in the network infrastructure of your application servers.

In the second phase (cap deploy), the frontend servers pull the current release from the intermediary server and install it locally.

This allows the servers to not require an installed SCM (e.g. git), and saves network bandwith, because the new release is no longer transmitted to all servers from an external source.

Add the following to your Capfile:

require 'capistrano/intermediate_host'

Add the following to your deploy.rb file:

set :scm, :intermediate_host
set :intermediate_host, "host.example.com"

These recipes will use the same capistrano directory structure on the intermediary host as on the application servers.

The tar Archives are stored as {deploy_to}/releases/{timestamp}.tar.gz with a {deploy_to}/current_tgz symlink pointing to the release tarfile that should be pulled in the second phase of the deployment process. This also allows your intermediary host to be a regular application server.

Unlike the default capistrano release path name, the release path will now consist of two timestamps: {deploy_to}/releases/{deployment_timestamp_of_phase2}_#{timestamp_of_release_preparation}/

Using this directory name format, you can deploy the same intermediary archive multiple times without conflicting with an existing deployment of the same version. This can come in handy in case you generate additional files during your deployment that are not part of the tar archive (e.g. rendering configuration file templates, locally compiled assets during deployment etc.).

# Host which acts as intermediary for the deployment files
# NOTE: only the primary host is currently evaluated
role :intermediate_host, "host.example.com"

# Which format git archive should output as. See the git archive manual page.
# Defaults to tar.gz
set :archive_format, "tar.gz"

# Where to output the generated git archive locally before uploading.
# Will use Tempfile.new by default to create non-static filename.
# The tempfile will be deleted after capistrano terminates.
set :archive_output, "myfile"

# Which branch git archive should generate the tar file from.
set :branch, "production"

• Only supports git at the moment
• Will only evaluate the primary intermediary host