This template deploys a Ruby on Rails application from a git repo under either unicorn & nginx, or mod_passenger & Apache 2 on multiple Linux servers with OpenStack Heat on the Rackspace Cloud, with either a Postgres or MySQL back end. This template uses the chef-solo provider to configure the servers.

• A Heat provider that supports the Rackspace OS::Heat::ChefSolo plugin.
• An OpenStack username, password, and tenant id.
• python-heatclient >= v0.2.8:

pip install python-heatclient

We recommend installing the client within a Python virtual environment.

Here is an example of how to deploy this template using the python-heatclient:

heat --os-username <OS-USERNAME> --os-password <OS-PASSWORD> --os-tenant-id \
  <TENANT-ID> --os-auth-url https://identity.api.rackspacecloud.com/v2.0/ \
  stack-create myrailsapp -f rails-app-multi.yaml \
  -P rails_rake_tasks=kandan:bootstrap -P rails_app_server_count=5 \
  -P rails_db_type=mysql -P rails_db_adapter=mysql2 \
  -P ruby_version=1.9.3-p547 -P app_git_url=https://github.com/myorg/myapp

• For UK customers, use https://lon.identity.api.rackspacecloud.com/v2.0/ as the --os-auth-url.

Optionally, set environment variables to avoid needing to provide these values every time a call is made:

export OS_USERNAME=<USERNAME>
export OS_PASSWORD=<PASSWORD>
export OS_TENANT_ID=<TENANT-ID>
export OS_AUTH_URL=<AUTH-URL>

Parameters can be replaced with your own values when standing up a stack. Use the -P flag to specify a custom parameter.

• server_hostnames: Hostname to give the Cloud Servers (Default: rails-%index%, note %index% is replaced with the resource index ID for each application node (0, 1, 2, ... n)))
• image: Operating system to use for all servers in this deployment. (Default: Ubuntu 12.04 LTS (Precise Pangolin))
• flavor: Server size to use for the application servers. (Default: 4 GB Performance)
• db_flavor: Server size to use for the database server. (Default: 4 GB Performance)
• additional_packages: Space delimited list of additional system packages to install. List any packages here required for your Gems to build. (Default: none)
• domain: Domain to be used with the rails app site, this will be used when setting up web services. (Default: rails.example.com)
• ruby_version: Version of Ruby to install (Default: 2.1.2)
• rails_environment: String to use as the rails environment name (Default: production)
• rails_db_type: Type of database to install, either postgresql or mysql. (Default: mysql)
• rails_db_adapter: Database adapter override. If supplied, this string will be used in the database.yml file to specify the adapter. By default rails_db_type will be used. You will need to use this for alternate adapters such as mysql2.
• rails_rake_tasks: a space-delimited list of additional rake tasks to run after db:migrate & assets:precompile (Default: none)
• rails_app_server: Application server to host your Rails application. unicorn implies nginx. Passenger implies apache. (Default: unicorn)
• rails_app_server_count: The number of Rails application servers to build. (Default: 2)
• app_git_url: Specifies a git URL from which to deploy the app (Default: none)
• app_git_revision: Git branch, tag, or commit hash of the application revision to deploy (Default: master)
• app_git_deploy_key: Key for deployment from a private git repo. (Default: none)
• database_name: Database name to use for the Rails application. (Default: railsapp_db)
• database_username: Username to use for the Rails application. (Default: railsapp_user)
• child_template: Location of the template to use for creating all Rails servers. (Default: https://raw.githubusercontent.com/rackspace-orchestration-templates/rails-app-multi/master/rails-app-server.yaml)
• kitchen: URL for the kitchen to clone with git. The Chef Solo run will copy all files in this repo into the kitchen for the chef run. (Default: https://github.com/rackspace-orchestration-templates/rails-app-multi)
• chef_version: Chef client version to install for the chef run. (Default: 11.12.8)
• load_balancer_hostname: Hostname to give the Cloud Load Balancer (Default: Rails-app-load-balancer)

Once a stack comes online, use heat output-list to see all available outputs. Use heat output-show <OUTPUT NAME> to get the value fo a specific output.

• private_key: SSH private that can be used to login as root to the servers.
• server_public_ips: List of Rails application server IPs.
• database_server_ip: Database Server IP.
• load_balancer_ip: IP of the Load Balancer created with this deployment.
• db_admin_password: Database administrator password.
• rails_app_url: URL to access your Rails application via the load balancer

For multi-line values, the response will come in an escaped form. To get rid of the escapes, use echo -e '<STRING>' > file.txt. For vim users, a substitution can be done within a file using %s/\\n/\r/g.

The application is deployed Capistrano-style in the home directory of the rails user in a directory based on the name of the git repo.

Gems dependencies are installed by running a bundle install --deployment in the application directory. This requires a Gemfile.lock in the application repo.

Two rake tasks are run at deployment time: rake db:migrate followed by rake assets:precompile

If you are using unicorn it must be declared in the application's Gemfile.

A unicorn.rb file is generated and placed in the application's config directory along with a database.yml file configured to reference the deployment's database server.

There are substantial changes still happening within the OpenStack Heat project. Template contribution guidelines will be drafted in the near future.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.