Remote

Remote is a small tool for running bash scripts on a collection of remote servers. It consists of a small library which handles compiling and running bash scripts on remote servers, a "task" library which can be used inside of rake tasks which adds some conventions, and a handful of common tasks.

This is all pretty experimental and non-flushed-out, so expect the API to change wildly :)

Remote is heavily inspired by relay and tele.

Usage

To use the remote rake tasks, in your rakefile:

$:.unshift("vendor/remote/lib")
Dir["vendor/remote/lib/tasks/**/*.rake"].each{ |r| import File.expand_path(r) }

Using the remote lib:

~/Sites/my_app/config/ssh_config:

Host development
  Hostname 33.33.33.144
  User vagrant
  
Host production-1
  Hostname 127.0.0.1
  User root
  
Host production-2
  Hostname 127.0.0.2
  User root

remote = Remote.new "~/Sites/my_app/deploy/ssh_config", verbose: true
remote.run %w( production-1 production-2 ), %w( ~/Sites/my_app/deploy/recipes/env.sh ~/Sites/my_app/deploy/recipes/provision.sh )

Provisioning & Deployment

Remote comes with a remote:deploy task which can be used to provision a set of servers and/or deploy code to them. The setup is similar to tele:

/deploy/layout.json describes the environments, servers, and roles you will be deploying to:

{
  "roles": {
    "dev": [ "env", "admin", "ruby", "unicorn", "nginx", "gems", "deploy", "development" ],
    "app": [ "env", "admin", "ruby", "unicorn", "nginx", "gems", "deploy" ],
    "db": [ "env", "admin", "postgresql" ]
  },
  "environments": {
    "development": {
      "dev": "development"
    }
    "staging": {
      "app": "staging",
      "db": "staging"
    },
    "production": {
      "app": [
        "production-1",
        "production-2",
        "production-3",
        "production-4"
      ],
      "db": "production-db"
    }
  }
}

deploy/ssh_config contains an application-specific SSH configuration for your servers:

Host development
  Hostname 33.33.33.144
  User vagrant

Host staging
  Hostname 192.0.43.20
  User root

Host production-db
  Hostname 192.0.43.10
  User root
Host production-1
  Hostname 192.0.43.11
  User root
Host production-2
  Hostname 192.0.43.12
  User root
Host production-3
  Hostname 192.0.43.13
  User root
Host production-4
  Hostname 192.0.43.14
  User root

Finally, the "roles" in layout.json define the names of recipes to be run in deploy/recipes. So tying it all together, running rake remote:deploy ENV=production would run the scripts (in the order defined):

deploy/recipes/env.sh
deploy/recipes/admin.sh
deploy/recipes/ruby.sh
deploy/recipes/unicorn.sh
deploy/recipes/nginx.sh
deploy/recipes/gems.sh
deploy/recipes/deploy.sh

On the production-1, production-2, production-3 & production-4 servers. Then it would run the scripts:

deploy/recipes/env.sh
deploy/recipes/admin.sh
deploy/recipes/postgresql.sh

On the production-db server.

See remote-recipes for an example collection of bash scripts.

Writing Recipes

Remote compiles all the bash scripts into a single script before running them on the remote servers. This way they all run in a single session and can share an environment (provided you pass the environment via -E any time you use sudo).