Default to lsb_release for detecting the Linux distro

lib/knife-solo/bootstraps/linux.rb

@@ -1,8 +1,13 @@
 module KnifeSolo::Bootstraps
   class Linux < Base
-
     def issue
-      prepare.run_command("cat /etc/issue").stdout.strip || prepare.run_command("lsb_release -d -s").stdout.strip
+      commands = [
+        'lsb_release -d -s',
+        'cat /etc/redhat-release',
+        'cat /etc/issue'
+      ]
+      result = prepare.run_with_fallbacks(commands)
+      result.success? ? result.stdout.strip : nil
     end
 
     def x86?
@@ -83,7 +88,7 @@ def distro
       when %r{This is \\n\.\\O \(\\s \\m \\r\) \\t}
         {:type => "emerge_gem"}
       else
-        raise "Distro not recognized from looking at /etc/issue. Please fork https://github.com/matschaffer/knife-solo and add support for your distro."
+        raise "Distribution not recognized. Please run again with `-VV` option and file an issue: https://github.com/matschaffer/knife-solo/issues"
       end
       Chef::Log.debug("Distro detection yielded: #{@distro}")
       @distro

lib/knife-solo/ssh_command.rb

@@ -154,7 +154,8 @@ def startup_script
     class ExecResult
       attr_accessor :stdout, :stderr, :exit_code
 
-      def initialize
+      def initialize(exit_code = nil)
+        @exit_code = exit_code
         @stdout = ""
         @stderr = ""
       end
@@ -208,7 +209,7 @@ def processed_command(command, options = {})
       command
     end
 
-    def run_command(command, options={})
+    def run_command(command, options = {})
       defaults = {:process_sudo => true}
       options = defaults.merge(options)
 
@@ -254,6 +255,17 @@ def run_command(command, options={})
       result
     end
 
+    # Runs commands from the specified array until successful.
+    # Returns the result of the successful command or an ExecResult with
+    # exit_code 1 if all fail.
+    def run_with_fallbacks(commands, options = {})
+      commands.each do |command|
+        result = run_command(command, options)
+        return result if result.success?
+      end
+      ExecResult.new(1)
+    end
+
     # TODO:
     # - move this to a dedicated "portability" module?
     # - use ruby in all cases instead?

test/ssh_command_test.rb

@@ -112,6 +112,33 @@ def test_barks_without_atleast_a_hostname
     assert_exits { cmd.validate_ssh_options! }
   end
 
+  def test_run_with_fallbacks_returns_first_successful_result
+    cmds = sequence("cmds")
+    cmd = command
+    cmd.expects(:run_command).with("first", {}).returns(result(1, "fail")).in_sequence(cmds)
+    cmd.expects(:run_command).with("second", {}).returns(result(0, "w00t")).in_sequence(cmds)
+    cmd.expects(:run_command).never
+
+    res = cmd.run_with_fallbacks(["first", "second", "third"])
+    assert_equal "w00t", res.stdout
+    assert res.success?
+  end
+
+  def test_run_with_fallbacks_returns_error_if_all_fail
+    cmd = command
+    cmd.expects(:run_command).twice.returns(result(64, "fail"))
+
+    res = cmd.run_with_fallbacks(["foo", "bar"])
+    assert_equal "", res.stdout
+    assert_equal 1, res.exit_code
+  end
+
+  def result(code, stdout = "")
+    res = KnifeSolo::SshCommand::ExecResult.new(code)
+    res.stdout = stdout
+    res
+  end
+
   def command(*args)
     Net::SSH::Config.stubs(:default_files)
     knife_command(DummySshCommand, *args)