Merge ~cjwatson/ols-charm-deps:wsgi-restart-on-version-info-change into ols-charm-deps:master

[Colin Watson]

Restart gunicorn if version-info.txt changes

If we're in symlink-switch mode, then we need to restart gunicorn when a new payload has been deployed; but this may not correspond to any of the configuration changes that ols-wsgi detects. Since services generally want to ship a version-info.txt anyway, add that to the list of files that trigger a hard restart if they're changed.

[Guillermo Gonzalez (verterok)]

+1
nice way to handle it

review: Approve

diff --git a/layer/ols-wsgi/reactive/ols_wsgi.py b/layer/ols-wsgi/reactive/ols_wsgi.py
index 7ca340b..123bff1 100644
--- a/layer/ols-wsgi/reactive/ols_wsgi.py
+++ b/layer/ols-wsgi/reactive/ols_wsgi.py
@@ -37,7 +37,8 @@ def configure_gunicorn():
 def needs_restart():
 
     restart = None
-    if helpers.any_file_changed([wsgi.environment_file()]):
+    if helpers.any_file_changed(
+            [wsgi.environment_file(), base.version_info_path()]):
         restart = 'hard'
     elif helpers.any_file_changed(wsgi.config_files()):
         restart = 'soft'
diff --git a/layer/ols/lib/ols/base.py b/layer/ols/lib/ols/base.py
index df9d984..d7955fd 100644
--- a/layer/ols/lib/ols/base.py
+++ b/layer/ols/lib/ols/base.py
@@ -115,6 +115,10 @@ def payload_dir():
     return os.path.join(hookenv.charm_dir(), 'files')
 
 
+def version_info_path():
+    return os.path.join(code_dir(), 'version-info.txt')
+
+
 def logs():
     return _layer_options().get('logs', {})
 
diff --git a/layer/ols/reactive/ols.py b/layer/ols/reactive/ols.py
index dcc9b01..b8f2735 100644
--- a/layer/ols/reactive/ols.py
+++ b/layer/ols/reactive/ols.py
@@ -17,6 +17,7 @@ from ols.base import (
     payload_name,
     logs,
     service_name,
+    version_info_path,
 )
 
 from charmhelpers.core import hookenv
@@ -32,7 +33,7 @@ def install_service():
     install_payload(payload_name(), code_dir(), 'root')
     hookenv.status_set('waiting',
                        'Service installed, but not configured.')
-    version_info = os.path.join(code_dir(), 'version-info.txt')
+    version_info = version_info_path()
     if os.path.exists(version_info):
         with open(version_info) as version_file:
             hookenv.application_version_set(version_file.read().strip())
diff --git a/layer/ols/unit_tests/test_ols.py b/layer/ols/unit_tests/test_ols.py
index adef577..0a9ec90 100644
--- a/layer/ols/unit_tests/test_ols.py
+++ b/layer/ols/unit_tests/test_ols.py
@@ -122,6 +122,10 @@ class BaseTest(TestCase):
         self.assertEqual(base.payload_dir(),
                          os.path.join(self.charm_dir, 'files'))
 
+    def test_version_info_path(self):
+        self.assertEqual(base.version_info_path(),
+                         '/srv/testservice/code/version-info.txt')
+
     def test_logs(self):
         expected = {
             '/var/log/celery.log': {'type': 'talisker'},