Enable dynamic creation of uwsgi pyargv option

Specifying hard-coded config files via the uwsgi pyargv option
caused failures when a file didn't exist.

This patch enables dynamic creation of the pyargv option. This
value is pushed onto the context for templated file generation
which is now supported as a subelement of an entry point as
well as a top level global option.

Change-Id: I1d0fae42b2e43fe8808fda3de83e122502233a4c

snap_openstack/base.py

@@ -131,6 +131,7 @@ class OpenStackSnap(object):
 
     def execute(self, argv):
         '''Execute snap command building out configuration and log options'''
+        renderer = SnapFileRenderer()
         utils = SnapUtils()
 
         entry_point = self.configuration['entry_points'].get(argv[1])
@@ -180,16 +181,56 @@ class OpenStackSnap(object):
             cmd = ["{snap}/bin/uwsgi".format(**utils.snap_env)]
             defaults = [d.format(**utils.snap_env) for d in DEFAULT_UWSGI_ARGS]
             cmd.extend(defaults)
+            pyargv = []
 
             uwsgi_dir = entry_point.get('uwsgi-dir')
             if uwsgi_dir:
                 uwsgi_dir = uwsgi_dir.format(**utils.snap_env)
                 cmd.append(uwsgi_dir)
 
+            uwsgi_log = entry_point.get('uwsgi-log')
+            if uwsgi_log:
+                uwsgi_log = uwsgi_log.format(**utils.snap_env)
+                cmd.extend(['--logto', uwsgi_log])
+
+            for cfile in entry_point.get('config-files', []):
+                cfile = cfile.format(**utils.snap_env)
+                if os.path.exists(cfile):
+                    pyargv.append('--config-file={}'.format(cfile))
+                else:
+                    LOG.debug('Configuration file {} not found'
+                              ', skipping'.format(cfile))
+
+            for cdir in entry_point.get('config-dirs', []):
+                cdir = cdir.format(**utils.snap_env)
+                if os.path.exists(cdir):
+                    pyargv.append('--config-dir={}'.format(cdir))
+                else:
+                    LOG.debug('Configuration directory {} not found'
+                              ', skipping'.format(cdir))
+
             log_file = entry_point.get('log-file')
             if log_file:
                 log_file = log_file.format(**utils.snap_env)
-                cmd.extend(['--logto', log_file])
+
+                pyargv.append('--log-file={}'.format(log_file))
+
+            # NOTE(jamespage): Pass dynamically built pyargv into
+            #                  context for template generation.
+            snap_env = utils.snap_env
+            if pyargv:
+                snap_env['pyargv'] = ' '.join(pyargv)
+
+            for template in entry_point.get('templates', []):
+                target = entry_point['templates'][template]
+                target_file = target.format(**utils.snap_env)
+                utils.ensure_dir(target_file, is_file=True)
+                if not os.path.isfile(target_file):
+                    LOG.debug('Rendering {} to {}'.format(template,
+                                                          target_file))
+                    with open(target_file, 'w') as tf:
+                        os.fchmod(tf.fileno(), 0o640)
+                        tf.write(renderer.render(template, snap_env))
 
         elif cmd_type == NGINX_EP_TYPE:
             cmd = ["{snap}/usr/sbin/nginx".format(**utils.snap_env)]

snap_openstack/tests/data/snap-openstack.yaml

@@ -28,7 +28,14 @@ entry_points:
   keystone-uwsgi:
     type: uwsgi
     uwsgi-dir: "/etc/uwsgi"
-    log-file: "/var/log/uwsgi/keystone.log"
+    uwsgi-log: "/var/log/uwsgi/keystone.log"
+    config-files:
+      - "/etc/keystone/keystone.conf"
+    config-dirs:
+      - "/etc/keystone/conf.d"
+    log-file: "/var/log/keystone/keystone.log"
+    templates:
+      "admin.ini.j2": "/etc/uwsgi/admin.ini"
   keystone-nginx:
     type: nginx
     config-file: "/etc/nginx/keystone/nginx.conf"

snap_openstack/tests/test_snap_openstack.py

@@ -51,9 +51,11 @@ class TestOpenStackSnapExecute(test_base.TestCase):
         snap_utils.snap_env = MOCK_SNAP_ENV
         snap_utils.drop_privileges.return_value = None
 
+    @patch.object(base, 'SnapFileRenderer')
     @patch('snap_openstack.base.SnapUtils')
     @patch.object(base, 'os')
-    def test_base_snap_config(self, mock_os, mock_utils):
+    def test_base_snap_config(self, mock_os, mock_utils,
+                              mock_renderer):
         '''Ensure wrapped binary called with full args list'''
         self.mock_snap_utils(mock_utils)
         snap = base.OpenStackSnap(os.path.join(TEST_DIR,
@@ -69,9 +71,11 @@ class TestOpenStackSnapExecute(test_base.TestCase):
              '--log-file=/var/log/nova/scheduler.log']
         )
 
+    @patch.object(base, 'SnapFileRenderer')
     @patch('snap_openstack.base.SnapUtils')
     @patch.object(base, 'os')
-    def test_base_snap_config_no_logging(self, mock_os, mock_utils):
+    def test_base_snap_config_no_logging(self, mock_os, mock_utils,
+                                         mock_renderer):
         '''Ensure wrapped binary called correctly with no logfile'''
         self.mock_snap_utils(mock_utils)
         snap = base.OpenStackSnap(os.path.join(TEST_DIR,
@@ -88,9 +92,11 @@ class TestOpenStackSnapExecute(test_base.TestCase):
              'db', 'sync']
         )
 
+    @patch.object(base, 'SnapFileRenderer')
     @patch('snap_openstack.base.SnapUtils')
     @patch.object(base, 'os')
-    def test_base_snap_config_missing_entry_point(self, mock_os, mock_utils):
+    def test_base_snap_config_missing_entry_point(self, mock_os, mock_utils,
+                                                  mock_renderer):
         '''Ensure ValueError raised for missing entry_point'''
         self.mock_snap_utils(mock_utils)
         snap = base.OpenStackSnap(os.path.join(TEST_DIR,
@@ -101,9 +107,11 @@ class TestOpenStackSnapExecute(test_base.TestCase):
                           ['snap-openstack',
                            'nova-api'])
 
+    @patch.object(base, 'SnapFileRenderer')
     @patch('snap_openstack.base.SnapUtils')
     @patch.object(base, 'os')
-    def test_base_snap_config_uwsgi(self, mock_os, mock_utils):
+    def test_base_snap_config_uwsgi(self, mock_os, mock_utils,
+                                    mock_renderer):
         '''Ensure wrapped binary of uwsgi called with correct arguments'''
         self.mock_snap_utils(mock_utils)
         snap = base.OpenStackSnap(os.path.join(TEST_DIR,
@@ -119,9 +127,11 @@ class TestOpenStackSnapExecute(test_base.TestCase):
              '--logto', '/var/log/uwsgi/keystone.log']
         )
 
+    @patch.object(base, 'SnapFileRenderer')
     @patch('snap_openstack.base.SnapUtils')
     @patch.object(base, 'os')
-    def test_base_snap_config_nginx(self, mock_os, mock_utils):
+    def test_base_snap_config_nginx(self, mock_os, mock_utils,
+                                    mock_renderer):
         '''Ensure wrapped binary of nginx called with correct arguments'''
         self.mock_snap_utils(mock_utils)
         snap = base.OpenStackSnap(os.path.join(TEST_DIR,
@@ -135,9 +145,11 @@ class TestOpenStackSnapExecute(test_base.TestCase):
              'daemon on; master_process on;']
         )
 
+    @patch.object(base, 'SnapFileRenderer')
     @patch('snap_openstack.base.SnapUtils')
     @patch.object(base, 'os')
-    def test_base_snap_config_invalid_ep_type(self, mock_os, mock_utils):
+    def test_base_snap_config_invalid_ep_type(self, mock_os, mock_utils,
+                                              mock_renderer):
         '''Ensure endpoint types are correctly validated'''
         self.mock_snap_utils(mock_utils)
         snap = base.OpenStackSnap(os.path.join(TEST_DIR,