crails-deploy

crails-deploy is a deployment tool designed to deploy web services on a remote Linux or FreeBSD server. The packages are designed to be extracted at the root of the remote server, using the Fileststem Hierarchy Standard. On top of extracting the content of the package to the root of the remote server, the deployment service will create:

• A directory in /var/lib for the application to have a place to write files to,
• A directory in /var/log for the application to store its logs
• A user and a group to run your webservice with
• An environment file
• A service file, designed for systemctl or rc (the former for Linux targets, the latter for FreeBSD targets) used to enable, start, stop or restart your service.
• Restrictive permissions to prevent your application from modifying itself in case of security breach, or any other user of the server to read the application's configuration files.

Installing

crails-deploy uses the build2 build system, and you may use this git repository as a build2 package.

We also provide an install script which should take care of everything. Just run the following command:

bash <(curl -s "https://raw.githubusercontent.com/crails-framework/crails-deploy/master/install.sh")

You will need to install libssh (libssh-dev for Debian, libssh-devel for Fedora) before installing crails-deploy.

Usage

Here's an example, deploying the package archive.tar.gz to [email protected], to be run by the webapp user:

$ crails-deploy \
  --package archive.tar.gz \
  --app-name myapp \
  --hostname 192.168.0.15 \
  --deploy-user ubuntu \
  --pubkey \
  --sudo \
  --user webapp \
  --group webapp \
  --start "/usr/local/bin/application" \
  --stop "/usr/local/bin/application-stop"

Using the app-name option to set our application name to myapp means that the runtime directory for our webservice will be /var/lib/myapp, a log folder will be created at /var/log/myapp, and the service will be named myapp in your service manager (systemctl or rc, depending on your system).

The start option is mandatory, and gives the entry point of your application. Similarly, the stop option allows you to set a script to be executed when stopping the service.

There are a few more options at your disposal, you may explore these using:

$ crails-deploy --help

Environment variables

crails-deploy creates an environment file for your application in the /usr/share/crails-deploy directory. The default environment file provides the following variables:

APPLICATION_NAME # value of the --app-name option
APPLICATION_HOST # value of the --app-host option, or 0.0.0.0 if unspecified
APPLICATION_PORT # value of the --app-port option, or 80 if unspecified
VAR_DIRECTORY    # value of the --runtime-path option, or /var/lib/$APPLICATION_NAME if unspecified 

These environment variables will be automatically loaded when running your start and stop executables. If you need to use your application's environment from another context, you can load it such as:

$ set -o allexport
$ . /usr/share/crails-deploy/myapp
$ set +o allexport

You may also add your own variables to this environment file using the --env option:

$ crails-deploy \
  ... \
  --env 'APPLICATION_DATABASE=postgres://user:password@localhost:5432' 'PRODUCTION=1'

You can also store these variables into a file and send them with the same --env option:

$ crails-deploy \
  ... \
  --env my.env

Environment files should use the following format to define variables:

APPLICATION_DATABASE="postgres://user:password@localhost:5432"
PRODUCTION=1