support custom admin user and user auth

In order to support cases where pools and keys are pre-created and
ceph-proxy just proxies this data to client applications this change
introduces support for:

* having custom "admin" users which may not actually have admin
privileges on the target cluster (client.admin is probably occupied by
real admins in this case);
* using cephx keys provided via charm config.

Change-Id: I01014b6986f92bf0ad8147a08afa1d61fdd5c088
Closes-bug: #1793991

config.yaml

@@ -59,3 +59,18 @@ options:
       .
       Valid options are "cephx" and "none". If "none" is specified, keys will
       still be created and deployed so that it can be enabled later.
+  user-keys:
+    type: string
+    default: ""
+    description: |
+      A space-separated list of <username>:<cephx-base64-key> pairs used to
+      lookup authentication keys for a specific user instead of trying to
+      create a user and a key via ceph-mon.
+  admin-user:
+    type: string
+    default: "client.admin"
+    description: |
+      A configurable admin user name. Used for scenarios where pools are
+      pre-created and the user given to charm-ceph-proxy simply needs to
+      check the existence of a given pool and error out if one does not
+      exist. Can be used in conjunction with user-keys.

hooks/ceph.py

@@ -31,6 +31,7 @@ from charmhelpers.core.hookenv import (
     cached,
     status_set,
     WARNING,
+    config,
 )
 from charmhelpers.fetch import (
     apt_cache
@@ -369,14 +370,30 @@ def get_upgrade_key():
     return get_named_key('upgrade-osd', _upgrade_caps)
 
 
+def _config_user_key(name):
+    user_keys_list = config('user-keys')
+    if user_keys_list:
+        for ukpair in user_keys_list.split(' '):
+            uk = ukpair.split(':')
+            if len(uk) == 2:
+                user_type, k = uk
+                t, u = user_type.split('.')
+                if u == name:
+                    return k
+
+
 def get_named_key(name, caps=None):
+    config_user_key = _config_user_key(name)
+    if config_user_key:
+        return config_user_key
+
     caps = caps or _default_caps
     cmd = [
         "sudo",
         "-u",
         ceph_user(),
         'ceph',
-        '--name', 'client.admin',
+        '--name', config('admin-user'),
         '--keyring',
         '/var/lib/ceph/mon/ceph-{}/keyring'.format(
             get_unit_hostname()

hooks/ceph_hooks.py

@@ -86,11 +86,16 @@ def emit_cephconf():
     render('ceph.conf', charm_ceph_conf, cephcontext, perms=0o644)
     install_alternative('ceph.conf', '/etc/ceph/ceph.conf',
                         charm_ceph_conf, 100)
-    keyring = 'ceph.client.admin.keyring'
+
+    keyring_template = 'ceph.keyring'
+    keyring = 'ceph.{}.keyring'.format(config('admin-user'))
     keyring_path = '/etc/ceph/' + keyring
-    ctx = {'admin_key': config('admin-key')}
+    ctx = {
+        'admin_key': config('admin-key'),
+        'admin_user': config('admin-user'),
+    }
     user = ceph.ceph_user()
-    render(keyring, keyring_path, ctx, owner=user, perms=0o600)
+    render(keyring_template, keyring_path, ctx, owner=user, perms=0o600)
 
     keyring = 'keyring'
     keyring_path = (

templates/ceph.keyring

@@ -1,3 +1,3 @@
-[client.admin]
+[{{ admin_user }}]
 	key = {{admin_key}}
 

templates/mon.keyring

@@ -1,3 +1,3 @@
-[client.admin]
+[{{ admin_user }}]
   key = {{admin_key}}
 

unit_tests/test_ceph.py

@@ -0,0 +1,95 @@
+import unittest
+
+import mock
+
+import ceph
+
+
+class CephTestCase(unittest.TestCase):
+    def setUp(self):
+        super(CephTestCase, self).setUp()
+
+    @staticmethod
+    def populated_config_side_effect(key):
+        return {
+            'user-keys':
+            'client.cinder-ceph:AQAij2tbMNjMOhAAqInpXQLFrltDgmYid6KXbg== '
+            'client.glance:AQCnjmtbuEACMxAA7joUmgLIGI4/3LKkPzUy8g== '
+            'client.gnocchi:AQDk7qJb0csAFRAAQqPU6HchVW3PT6ymgXdI/A== '
+            'client.nova-compute-kvm:'
+            'AQBkjmtb1hWxLxAA3UhxSblgFSCtHVoZ8W6rNQ== '
+            'client.radosgw.gateway:'
+            'AQBljmtb65mrHhAAGy9VRkfsatWVLb9EpoWDfw==',
+            'admin-user': 'client.myadmin'
+        }[key]
+
+    @staticmethod
+    def empty_config_side_effect(key):
+        return {
+            'user-keys': '',
+            'admin-user': 'client.myadmin'
+        }[key]
+
+    @mock.patch('ceph.config')
+    def test_config_user_key_populated(self, mock_config):
+        user_name = 'glance'
+        user_key = 'AQCnjmtbuEACMxAA7joUmgLIGI4/3LKkPzUy8g=='
+
+        mock_config.side_effect = self.populated_config_side_effect
+        named_key = ceph._config_user_key(user_name)
+        self.assertEqual(user_key, named_key)
+
+    @mock.patch('ceph.config')
+    def test_config_empty_user_key(self, mock_config):
+        user_name = 'cinder-ceph'
+
+        mock_config.side_effect = self.empty_config_side_effect
+        named_key = ceph._config_user_key(user_name)
+        self.assertEqual(named_key, None)
+
+    @mock.patch('ceph.config')
+    def test_get_named_key_populated(self, mock_config):
+        user_name = 'glance'
+        user_key = 'AQCnjmtbuEACMxAA7joUmgLIGI4/3LKkPzUy8g=='
+
+        mock_config.side_effect = self.populated_config_side_effect
+        named_key = ceph.get_named_key(user_name)
+
+        self.assertEqual(user_key, named_key)
+
+    @mock.patch('subprocess.check_output')
+    @mock.patch('ceph.get_unit_hostname')
+    @mock.patch('ceph.ceph_user')
+    @mock.patch('ceph.config')
+    def test_get_named_key_empty(self, mock_config, mock_ceph_user,
+                                 mock_get_unit_hostname, mock_check_output):
+        user_name = 'cinder-ceph'
+        user_type = 'client'
+        admin_user = 'client.myadmin'
+        user_spec = '{}.{}'.format(user_type, user_name)
+        expected_key = 'AQCnjmtbuEACMxAA7joUmgLIGI4/3LKkPzUy8g=='
+        expected_output = ('[client.testuser]\n        key = {}'
+                           .format(expected_key))
+        caps = {
+            'mon': ['allow rw'],
+            'osd': ['allow rwx']
+        }
+        ceph_user = 'ceph'
+        ceph_proxy_host = 'cephproxy'
+        mock_get_unit_hostname.return_value = ceph_proxy_host
+
+        def check_output_side_effect(cmd):
+            return {
+                ' '.join(['sudo', '-u', ceph_user, 'ceph', '--name',
+                          admin_user,
+                          '--keyring',
+                          '/var/lib/ceph/mon/ceph-{}/keyring'.format(
+                              ceph_proxy_host),
+                          'auth', 'get-or-create', user_spec, 'mon',
+                          'allow rw', 'osd', 'allow rwx']): expected_output
+            }[' '.join(cmd)]
+        mock_check_output.side_effect = check_output_side_effect
+        mock_config.side_effect = self.empty_config_side_effect
+        mock_ceph_user.return_value = ceph_user
+        named_key = ceph.get_named_key(user_name, caps)
+        self.assertEqual(named_key, expected_key)

unit_tests/test_ceph_hooks.py

@@ -76,6 +76,7 @@ class TestHooks(test_utils.CharmTestCase):
         self.test_config.set('monitor-hosts', '127.0.0.1:1234')
         self.test_config.set('fsid', 'abc123')
         self.test_config.set('admin-key', 'key123')
+        self.test_config.set('admin-user', 'client.myadmin')
 
         def c(k):
             x = {'radosgw': ['rados:1'],
@@ -105,10 +106,15 @@ class TestHooks(test_utils.CharmTestCase):
                                                     '/etc/ceph/ceph.conf',
                                                     '%s/ceph.conf' % dirname,
                                                     100)
-        keyring = 'ceph.client.admin.keyring'
+        keyring_template = 'ceph.keyring'
-        context = {'admin_key': self.test_config.get('admin-key')}
+        keyring_name = 'ceph.{}.keyring'.format(
-        self.render.assert_any_call(keyring,
+            self.test_config.get('admin-user'))
-                                    '/etc/ceph/' + keyring,
+        context = {
+            'admin_key': self.test_config.get('admin-key'),
+            'admin_user': self.test_config.get('admin-user'),
+        }
+        self.render.assert_any_call(keyring_template,
+                                    '/etc/ceph/' + keyring_name,
                                     context, owner='ceph-user', perms=0o600)
 
         mock_rgw_rel.assert_called_with(relid='rados:1', unit='rados/1')