Reviewers: mp+202299_code.launchpad.net,

Message:
Please take a look.

Description:
Support the new juju switch behavior.

Quickstart is now able to retrieve the
default environment name in newer
versions of juju-core.

Tests: `make check`.
No QA required.

https://code.launchpad.net/~frankban/juju-quickstart/new-juju-switch/+merge/202299

(do not edit description out of merge proposal)


Please review this at https://codereview.appspot.com/54560043/

Affected files (+25, -15 lines):
   A [revision details]
   M quickstart/models/envs.py
   M quickstart/tests/models/test_envs.py


Index: [revision details]
=== added file '[revision details]'
--- [revision details]	2012-01-01 00:00:00 +0000
+++ [revision details]	2012-01-01 00:00:00 +0000
@@ -0,0 +1,2 @@
+Old revision:  
<email address hidden>
+New revision:  
<email address hidden>

Index: quickstart/models/envs.py
=== modified file 'quickstart/models/envs.py'
--- quickstart/models/envs.py	2014-01-16 12:41:47 +0000
+++ quickstart/models/envs.py	2014-01-20 12:02:10 +0000
@@ -111,19 +111,22 @@
      env_name = os.getenv('JUJU_ENV', '').strip()
      if env_name:
          return env_name
-    # XXX 2013-10-16 frankban bug=1193244:
-        # Support the new behavior of juju-switch, currently under  
development:
-        # the command will just output the environment name, or exit with  
an
-        # error if no default environment is configured.
      # The "juju switch" command parses ~/.juju/current-environment file.  
If the
      # environment name is not found there, then it tries to retrieve the  
name
      # from the "default" section of the ~/.juju/environments.yaml file.
      retcode, output, _ = utils.call('juju', 'switch')
+    # Before juju-core 1.17, the "juju switch" command returns a human  
readable
+    # output. Newer releases just output the environment name, or exit  
with an
+    # error if no default environment is configured.
      if retcode:
          return None
+    # Use a regular expression to check if "juju switch" returned a human
+    # readable output.
      match = _juju_switch_expression.match(output)
      if match is not None:
          return match.groups()[0]
+    # At this point we can safely assume we are using the newer "juju  
switch".
+    return output.strip()


  def create_empty_env_db():


Index: quickstart/tests/models/test_envs.py
=== modified file 'quickstart/tests/models/test_envs.py'
--- quickstart/tests/models/test_envs.py	2014-01-16 12:41:47 +0000
+++ quickstart/tests/models/test_envs.py	2014-01-20 12:02:10 +0000
@@ -58,9 +58,10 @@
                  env_name = envs.get_default_env_name()
          self.assertIsNone(env_name)

-    def test_juju_switch(self):
-        # The environment name is successfully returned if previously set  
using
-        # the "juju switch" command.
+    def test_juju_switch_old_behavior(self):
+        # The environment name is successfully returned if retrievable  
using
+        # the "juju switch" command. This test exercises the old "juju  
switch"
+        # returning a human readable output.
          output = 'Current environment: "hp"\n'
          with self.patch_call(0, output=output) as mock_call:
              with mock.patch('os.environ', {}):
@@ -68,6 +69,18 @@
          self.assertEqual('hp', env_name)
          mock_call.assert_called_once_with('juju', 'switch')

+    def test_juju_switch_new_behavior(self):
+        # The environment name is successfully returned if retrievable  
using
+        # the "juju switch" command. This test exercises the new "juju  
switch"
+        # returning a machine readable output (just the name of the env).
+        # This new behavior has been introduced in juju-core 1.17.
+        output = 'ec2\n'
+        with self.patch_call(0, output=output) as mock_call:
+            with mock.patch('os.environ', {}):
+                env_name = envs.get_default_env_name()
+        self.assertEqual('ec2', env_name)
+        mock_call.assert_called_once_with('juju', 'switch')
+
      def test_juju_switch_failure(self):
          # The environment name is not found if "juju switch" returns an  
error.
          with self.patch_call(1) as mock_call:
@@ -76,14 +89,6 @@
          self.assertIsNone(env_name)
          mock_call.assert_called_once_with('juju', 'switch')

-    def test_juju_switch_nonsense(self):
-        # The environment name is not found if "juju switch" goes crazy.
-        with self.patch_call(0, output='Exterminate!') as mock_call:
-            with mock.patch('os.environ', {}):
-                env_name = envs.get_default_env_name()
-        self.assertIsNone(env_name)
-        mock_call.assert_called_once_with('juju', 'switch')
-

  class TestCreateEmptyEnvDb(unittest.TestCase):