Deploy to only one role / server with capistrano

I'm trying to set up multiple roles, one for live, and another for dev. They look like this:

role :live, "example.com"
role :dev, "dev.example.com"

When I run cap deploy, however, it executes for both servers. I've tried the following and it always executes on both.

cap deploy live
cap RO开发者_Python百科LE=live deploy

What am I missing? I know I can write a custom task that only responds to one role, but I don't want to have to write a whole bunch of tasks just to tell it to respond to one role or another. Thanks!

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Capistrano Multistage is definitely the solution to the example you posted for deploying to environments. In regard to your question of deploying to roles or servers, Capistrano has command-line solutions for that too.

To deploy to a single role (notice ROLES is plural):

cap ROLES=web deploy

To deploy to multiple roles:

cap ROLES=app,web deploy

To deploy to particular server (notice HOSTS is plural):

cap HOSTS=web1.myserver.com deploy

To deploy to several servers:

cap HOSTS=web1.myserver.com,web2.myserver.com deploy

To deploy to a server(s) with a role(s):

cap HOSTS=web1.myserver.com ROLES=db deploy

---

You can do something like this:

task :dev do
    role :env, "dev.example.com"
end

task :prod do
    role :env, "example.com"
end

Then use:

cap dev deploy
cap prod deploy

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Just one more hint: if you use multistage remember to put ROLES constant before cap command.

ROLES=web cap production deploy

or after environment

cap production ROLES=web deploy

If you put as first parameter, multistage will treat it as stage name and replace with default one:

cap ROLES=web production deploy

* [...] executing `dev'
* [...] executing `production'

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Try capistrano multistage:

http://weblog.jamisbuck.org/2007/7/23/capistrano-multistage

Roles are intended to deploy different segments on different servers, as apposed to deploying the whole platform to just one set of servers.