capistrano_multiconfig_parallel

DEMO

Description

CapistranoMulticonfigParallel is a simple ruby implementation that allows you to run multiple tasks in parallel for multiple applications and uses websockets for inter-process communication and has a interactive menu

IMPORTANT! The whole reason for this gem was for using Caphub in a more easy way and allowing you to run tasks in parallel for multiple aplications . However this can be used for normal applications also, if you want for example to deploy your app to multiple sandboxes on development environment or even deploy in parallel to multiple stages.

CAUTION!! PLEASE READ CAREFULLY!! Capistrano is not thread-safe. However in order to work around this problem, each of the task is executing inside a thread that spawns a new process in order to run capistrano tasks The thread monitors the process. This works well, however if the tasks you are executing is working with files, you might get into deadlocks because multiple proceses try to access same resource. Instead of using files , please consider using StringIO instead.

Requirements

Compatibility

Rails >3.0 only. MRI 1.9.x, 2.x

Ruby 1.8 is not officially supported. We will accept further compatibilty pull-requests but no upcoming versions will be tested against it.

Rubinius and Jruby support temporarily dropped due to Rails 4 incompatibility.

Installation Instructions

Add the following to your Gemfile:

  gem "capistrano_multiconfig_parallel"

Add the following to your Capfile after requiring capistrano and capistrano-multiconfig

  require 'capistrano_multiconfig_parallel'

Please read Release Details if you are upgrading. We break backward compatibility between large ticks but you can expect it to be specified at release notes.

Default Configuration:

---
multi_debug: true
multi_secvential: false
websocket_server:
  enable_debug: false

development_stages:
  - development
  - webdev

apply_stage_confirmation:
  - production  
task_confirmations:
  - deploy:symlink:release

application_dependencies: []
---

Available command line options when executing a command

--multi-debug
- if option is present and has value TRUE , will enable debugging of workers
--multi-secvential
- If parallel executing does not work for you, you can use this option so that each process is executed normally and ouputted to the screen. However this means that all other tasks will have to wait for each other to finish before starting
--websocket_server.enable_debug
- if option is present and has value TRUE, will enable debugging of websocket communication between the workers
--development_stages
- if option is present and has value an ARRAY of STRINGS, each of them will be used as a development stage
--apply_stage_confirmation
- If option is present and has value an ARRAY of STRING, each string should be the name of a stage. The confirmations will only be applied if the workers are executing tasks to one of that stage.
--task_confirmations:
- if option is present and has value an ARRAY of Strings (Task Names), then will require a confirmation from user before executing the task. This will syncronize all workers to wait before executing that task, then a confirmation will be displayed, and when user will confirm , all workers will resume their operation.
--application_dependencies
- This should be used only for Caphub-like applications , in order to deploy dependencies of an application in parallel and is described at section 2.) Multiple applications

Usage Instructions

In order to override default configurations, you can either specify them at runtime using command-line , or you can create a file in location config/multi_cap.yml . This settings will be overriden by command line arguments( if any)

1) Single Apps ( normal Rails or rack applications)

CapistranoMulticonfigParallel recognizes only "development" and "webdev" as stages for development if you use other stages for development, you need to configure it like this

---
development_stages:
  - development
  - webdev
  - something_custom
----

1.1) Deploying the application to multiple sandboxes ( works only with development environments)

# <box_name>     - the name of a sandbox
#<development_stage> - the name of one of the stages you previously configured
#<task_name> - the capistrano task that you want to execute ( example: 'deploy' )

bundle exec multi_cap  <development_stage> <task_name>   BOX=<box_name>,<box_name>

If a branch is specified using BRANCH=name it will deploy same branch to all sandboxes The branch environment variable is then passed to the capistrano task

Also the script will ask if there are any other environment variables that user might want to pass to each of the sandboxes separately.

1.2) Deploying the application to multiple stages ( Using the customized command "deploy_multi_stages")


bundle exec multi_cap deploy_multi_stages  STAGES=development, staging, production

NOTE: IF you want to execute a different command on all stages, you can specify environment variable ACTION=task_name either when you specify the STAGES, or can be done individually for each task when prompted about additional ENV options

If a branch is specified using BRANCH=name it will deploy same branch to all stages.The branch environment variable is then passed to the capistrano task

Also the script will ask if there are any other environment variables that user might want to pass to each of the stages separately.

If you use capistrano-gitflow, the workers will first deploy to all the other stages and only after staging is tagged , will trigger a new worker to start deploying to production

2.) Multiple Apps ( like Caphub )

Configuration for this types of application is more complicated

---
application_dependencies:
    - app: foo'
      priority: 1
      dependencies: []
    - app: bar
      priority: 1
      dependencies:
        - foo
    - app: foo2
      priority: 1
      dependencies:
        - foo
        - bar
---

The "development_stages" options is used so that the gem can know if sandboxes are allowed for those environments.

The dependencies are being kept in the option "application_dependencies" This is an array of hashes. Each hash has only the keys "app" ( app name), "priority" and "dependencies" ( an array of app names that this app is dependent to)

In this example, if we execute this command:

bundle exec multi_cap foo2:development deploy

Will ask user if he wants to deploy the apps "foo" and "bar" , since they appear in the dependencies list for the application "foo2"

1.2) Deploying multiple application to multiple stages ( Using the customized command "deploy_multi_stages")


bundle exec multi_cap deploy_multi_stages  STAGES=development, staging, production

If a branch is specified using BRANCH=branch_name it will deploy same branch to all stages.The branch environment variable is then passed to the capistrano task If you want different branches , capistrano will ask for additional ENV options for each stage, and can be specified then for each stage

If you use capistrano-gitflow, the workers will first deploy to all the other stages and only after staging is tagged , will trigger a new worker to start deploying to production

Known Limitations

Currently it works only if Celluloid.cores >= 2

Testing

To test, do the following:

cd to the gem root.
bundle install
bundle exec rake

Contributions

Please log all feedback/issues via Github Issues. Thanks.

Contributing to capistrano_multiconfig_parallel

Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.
Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.
Fork the project.
Start a feature/bugfix branch.
Commit and push until you are happy with your contribution.
Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.
You can read more details about contributing in the Contributing document