Question

I’m trying to configure Capistrano to do the same task on two different servers, each of them having different credentials. I’d like to do something simmilar to:

namespace :deploy do
  role :db,  "192.168.1.1", :credentials => "db1.yml"
  role :db,  "192.168.1.1", :credentials => "db2.yml"

  task :mytask, :roles => :db do
    credentials = YAML.load_file(something)
    ...

Is that possible? What should I substitute something with, in order to access the current server configuration?

Answer 1

OK, I finally had some time to solve this. Hopefully someone else will find this answer useful. Here’s how i eventually solved the problem:

role :db, "db1" ,{ :credentials => 'db1-credentials'}                     
role :db, "db2" ,{ :credentials => 'db2-credentials'}                     
role :db, "db3"

namespace :stackoverflow do

  # Don't run this task on host that don't have credentials defined
  task :default, {:role => :db, :except => {:credentials => nil } } do
    servers = find_servers_for_task(current_task)
    servers.each do |server|
      credentials = server.options[:credentials]

      puts credentials # actual task

    end
  end
end

I see now that I may had stated the question in a confusing way – that’s because I hadn’t understood, that task are run concurrently.

This will in fact execute the task (here puts credentials) once for each server, which was what I was trying to do.

Output:

$ cap stackoverflow
  * executing `stackoverflow'
db1-credentials
db2-credentials

It’s a good idea to add a filter to a task so it won’t run if the server has no credentials.

That being said, making everybody in the team maintain current (and for security reasons non-versioned) credentials to all servers turned out to be too much hassle (thus defeating the idea of using Capistrano). Now instead of keeping the external configuration on the disks of users I’m going to keep the data on the servers affected (mostly in form of runnable scripts with all credentials hidden inside). Like this:

task :dump {:role => :db} do
  run "/root/dump_db.sh | gzip > /tmp/dump.sql.gz"
  download "/tmp/dump.sql.gz", "somewhere"
end