Passing parameters to Capistrano
git clone johndoe@gitsrv.domain:app
cd app
git checkout r2s1

desc "Parameter Testing"
task :parameter do
  puts "Parameter test #{configuration[:branch]} #{configuration[:tag]}"
end

cap test:parameter -s branch=master -s tag=1.0.0

desc "Parameter Testing"
task :parameter do
  system("whoami", user)
  puts "Parameter test #{user} #{configuration[:branch]} #{configuration[:tag]}"
end

$ GIT_REPO="johndoe@gitsrv.domain:app" GIT_BRANCH="r2s1" cap testing

#deploy.rb:
task :testing, :roles => :app do
  puts ENV['GIT_REPO']
  puts ENV['GIT_BRANCH']
end

# deploy from git repo
set :repository, "git@git.mygitserver.com:mygitrepo.git"
# tells cap to use git
set :scm, :git

set :repository, "#{scm_user}@gitsrv.domain:app"

set :scm_user, 'someuser'