deploy.rb

class SSHKit::Backend::Netssh
  alias_method :command_orig, :command

  def command(*a)
    @user = 'test2' # TODO replace with user to sudo to
    command_orig(*a)
  ensure
    @user = nil
  end
end

# Replace capistrano tasks
stages.each do |stage|
  after stage, :hack do
    Rake::Task[:'deploy:log_revision'].clear
    namespace :deploy do
      desc 'Log details of the deploy'
      task :log_revision do
        on release_roles(:all) do
          within releases_path do
            # HACK execute with string doesn't respect @user ?
            # execute %{echo "#{revision_log_message}" >> #{revision_log}}
            execute :echo, "'#{revision_log_message}' >> #{revision_log}"
          end
        end
      end
    end

    Rake::Task[:'git:wrapper'].clear
    namespace :git do
      desc 'Upload the git wrapper script, this script guarantees that we can script git without getting an interactive prompt'
      task :wrapper do
        on release_roles :all do
          execute :mkdir, "-p", "#{fetch(:tmp_dir)}/#{fetch(:application)}/"
          # HACK upload doesn't respect @user
          # (known issue, see https://github.com/capistrano/sshkit/blob/master/EXAMPLES.md#upload-a-file-from-disk )
          # upload! StringIO.new("#!/bin/sh -e\nexec /usr/bin/ssh -o PasswordAuthentication=no -o StrictHostKeyChecking=no \"$@\"\n"), "#{fetch(:tmp_dir)}/#{fetch(:application)}/git-ssh.sh"
          code = "#!/bin/sh -e\nexec /usr/bin/ssh -o PasswordAuthentication=no -o StrictHostKeyChecking=no \"$@\"\n"
          execute :echo, "'#{code}' > #{fetch(:tmp_dir)}/#{fetch(:application)}/git-ssh.sh"
          execute :chmod, "+x", "#{fetch(:tmp_dir)}/#{fetch(:application)}/git-ssh.sh"
        end
      end
    end
  end
end