Add the possibility of using a dedicated private key

lib/rhc/commands/ssh.rb

@@ -15,6 +15,8 @@ class Ssh < Base
 
       You may run a specific SSH command by passing one or more arguments, or use a
       different SSH executable or pass options to SSH with the '--ssh' option.
+
+      A dedicated private key can be passed to SSH with the '--key' option.
 
       To use the '--ssh' flag with an SSH executable path containing a space, wrap
       the executable path with double quotes:
@@ -24,6 +26,7 @@ class Ssh < Base
     takes_application :argument => true
     argument :command, "Command to run in the application's SSH session", ['--command COMMAND'], :type => :list, :optional => true
     option ["--ssh PATH"], "Path to your SSH executable or additional options"
+    option ["--key KEY"], "Private KEY to use for the SSH connections. Requires a private key."
     option ["--gears"], "Execute this command on all gears in the app.  Requires a command."
     option ["--limit INTEGER"], "Limit the number of simultaneous SSH connections opened with --gears (default: 5).", :type => Integer, :default => 5
     option ["--raw"], "Output only the data returned by each host, no hostname prefix."
@@ -42,8 +45,12 @@ def run(_, command)
         $stderr.puts "Connecting to #{rest_app.ssh_string.to_s} ..." unless command.present?
 
         debug "Using user specified SSH: #{options.ssh}" if options.ssh
-
-        command_line = [RHC::Helpers.split_path(ssh), ('-vv' if debug?), rest_app.ssh_string.to_s, command].flatten.compact
+        debug "Using user specified SSH Private Key: #{options.key}" if options.key
+        if options.key
+          command_line = [RHC::Helpers.split_path(ssh), ('-vv' if debug?), rest_app.ssh_string.to_s, "-i", options.key, command].flatten.compact
+        else
+          command_line = [RHC::Helpers.split_path(ssh), ('-vv' if debug?), rest_app.ssh_string.to_s, command].flatten.compact
+        end
 
         debug "Invoking Kernel.exec with #{command_line.inspect}"
         Kernel.send(:exec, *command_line)

spec/rhc/commands/ssh_spec.rb

@@ -171,6 +171,32 @@
     end
   end
 
+  describe 'app ssh custom private key' do
+    let(:arguments) { ['app', 'ssh', 'app1', '--key', 'valid_private_key'] }
+
+    context 'when custom private key is valid' do
+      before(:each) do
+        @domain = rest_client.add_domain("mockdomain")
+        @domain.add_application("app1", "mock_type")
+        Kernel.should_receive(:exec).with("ssh", "fakeuuidfortestsapp1@127.0.0.1", "-i", "valid_private_key").and_return(0)
+        #subject.class.any_instance.stub(:discover_git_executable).and_return('git')
+      end
+      it { run_output.should match("Connecting to fakeuuidfortestsapp") }
+      it { expect{ run }.to exit_with_code(0) }
+    end
+
+    context 'when custom private key does not exist' do
+      let(:arguments) { ['app', 'ssh', 'app1', '--key', 'nonexistent_private_key'] }
+      it { expect { run }.to exit_with_code(1) } 
+    end
+
+    context 'when custom private key is inaccessible' do
+      let(:arguments) { ['app', 'ssh', 'app1', '--key', 'inaccessible_private_key'] }
+      it { expect { run }.to exit_with_code(1) }
+    end
+
+  end
+
   describe 'app ssh custom ssh with spaces and arguments' do
     let(:arguments) { ['app', 'ssh', 'app1', '--ssh', '"/path/to /ssh" --with_custom_flag'] }
     context 'when custom ssh does not exist as a path' do