sync down the content of a postgresql database used by a rails application using mina.

sync-postgres-mina.rb

RYAML = <<-BASH
function ryaml {
  ruby -ryaml -e 'puts ARGV[1..-1].inject(YAML.load(File.read(ARGV[0]))) {|acc, key| acc[key] }' "$@"
};
BASH

namespace :sync do
  task :db do
    isolate do
      invoke :environment

      queue RYAML
      queue "USERNAME=$(ryaml #{deploy_to}/shared/config/database.yml #{rails_env} username)"
      queue "PASSWORD=$(ryaml #{deploy_to}/shared/config/database.yml #{rails_env} password)"
      queue "DATABASE=$(ryaml #{deploy_to}/shared/config/database.yml #{rails_env} database)"
      queue "PGPASSWORD=$PASSWORD pg_dump -U $USERNAME $DATABASE -c -f #{deploy_to}/dump.sql"
      queue "gzip -f #{deploy_to}/dump.sql"

      mina_cleanup!
    end

    %x[scp #{user}@#{domain}:#{deploy_to}/dump.sql.gz .]
    %x[gunzip -f dump.sql.gz]
    %x[#{RYAML} psql -d $(ryaml config/database.yml development database) -f dump.sql]
    %x[rm dump.sql]
  end
end