Merge lp:~xfactor973/charm-helpers/ceph-keystore into lp:charm-helpers

[Chris Holcombe]

This change adds functionality to the ceph contrib library to allow using the ceph monitor cluster as a generic key/value store.

[James Page (james-page)]

Hi Chris

Generally this looks OK - but please could you add some unit tests around monitor_key_exists.

Other than that LGTM

review: Needs Fixing

[lp:~xfactor973/charm-helpers/ceph-keystore]

535. By Chris Holcombe on 2016-03-02

Add more unit tests and fix the CalledProcessError message

=== modified file 'charmhelpers/contrib/storage/linux/ceph.py'
--- charmhelpers/contrib/storage/linux/ceph.py	2016-02-22 15:18:38 +0000
+++ charmhelpers/contrib/storage/linux/ceph.py	2016-03-02 18:16:59 +0000
@@ -24,6 +24,8 @@
 #  Adam Gandelman <[e-mail]>
 #
 import bisect
+import errno
+import hashlib
 import six
 
 import os
@@ -163,7 +165,7 @@
         :return: None
         """
         # read-only is easy, writeback is much harder
-        mode = get_cache_mode(cache_pool)
+        mode = get_cache_mode(self.service, cache_pool)
         if mode == 'readonly':
             check_call(['ceph', '--id', self.service, 'osd', 'tier', 'cache-mode', cache_pool, 'none'])
             check_call(['ceph', '--id', self.service, 'osd', 'tier', 'remove', self.name, cache_pool])
@@ -259,6 +261,134 @@
        Returns json formatted output"""
 
 
+def get_mon_map(service):
+    """
+    Returns the current monitor map.
+    :param service: six.string_types. The Ceph user name to run the command under
+    :return: json string. :raise: ValueError if the monmap fails to parse.
+      Also raises CalledProcessError if our ceph command fails
+    """
+    try:
+        mon_status = check_output(
+            ['ceph', '--id', service,
+             'ceph', 'mon_status', '--format=json'])
+        try:
+            return json.loads(mon_status)
+        except ValueError as v:
+            log("Unable to parse mon_status json: {}. Error: {}".format(
+                mon_status, v.message))
+            raise
+    except CalledProcessError as e:
+        log("mon_status command failed with message: {}".format(
+            e.message))
+        raise
+
+
+def hash_monitor_names(service):
+    """
+    Uses the get_mon_map() function to get information about the monitor
+    cluster.
+    Hash the name of each monitor.  Return a sorted list of monitor hashes
+    in an ascending order.
+    :param service: six.string_types. The Ceph user name to run the command under
+    :rtype : dict.   json dict of monitor name, ip address and rank
+    example: {
+        'name': 'ip-172-31-13-165',
+        'rank': 0,
+        'addr': '172.31.13.165:6789/0'}
+    """
+    try:
+        hash_list = []
+        monitor_list = get_mon_map(service=service)
+        if monitor_list['monmap']['mons']:
+            for mon in monitor_list['monmap']['mons']:
+                hash_list.append(
+                    hashlib.sha224(mon['name'].encode('utf-8')).hexdigest())
+            return sorted(hash_list)
+        else:
+            return None
+    except (ValueError, CalledProcessError):
+        raise
+
+
+def monitor_key_delete(service, key):
+    """
+    Delete a key and value pair from the monitor cluster
+    :param service: six.string_types. The Ceph user name to run the command under
+    Deletes a key value pair on the monitor cluster.
+    :param key: six.string_types.  The key to delete.
+    """
+    try:
+        check_output(
+            ['ceph', '--id', service,
+             'ceph', 'config-key', 'del', str(key)])
+    except CalledProcessError as e:
+        log("Monitor config-key put failed with message: {}".format(
+            e.output))
+        raise
+
+
+def monitor_key_set(service, key, value):
+    """
+    Sets a key value pair on the monitor cluster.
+    :param service: six.string_types. The Ceph user name to run the command under
+    :param key: six.string_types.  The key to set.
+    :param value: The value to set.  This will be converted to a string
+        before setting
+    """
+    try:
+        check_output(
+            ['ceph', '--id', service,
+             'ceph', 'config-key', 'put', str(key), str(value)])
+    except CalledProcessError as e:
+        log("Monitor config-key put failed with message: {}".format(
+            e.output))
+        raise
+
+
+def monitor_key_get(service, key):
+    """
+    Gets the value of an existing key in the monitor cluster.
+    :param service: six.string_types. The Ceph user name to run the command under
+    :param key: six.string_types.  The key to search for.
+    :return: Returns the value of that key or None if not found.
+    """
+    try:
+        output = check_output(
+            ['ceph', '--id', service,
+             'ceph', 'config-key', 'get', str(key)])
+        return output
+    except CalledProcessError as e:
+        log("Monitor config-key get failed with message: {}".format(
+            e.output))
+        return None
+
+
+def monitor_key_exists(service, key):
+    """
+    Searches for the existence of a key in the monitor cluster.
+    :param service: six.string_types. The Ceph user name to run the command under
+    :param key: six.string_types.  The key to search for
+    :return: Returns True if the key exists, False if not and raises an
+     exception if an unknown error occurs. :raise: CalledProcessError if
+     an unknown error occurs
+    """
+    try:
+        check_call(
+            ['ceph', '--id', service,
+             'config-key', 'exists', str(key)])
+        # I can return true here regardless because Ceph returns
+        # ENOENT if the key wasn't found
+        return True
+    except CalledProcessError as e:
+        if e.returncode == errno.ENOENT:
+            return False
+        else:
+            log("Unknown error from ceph config-get exists: {} {}".format(
+                e.returncode, e.output))
+            raise
+
+
 def get_erasure_profile(service, name):
     """
     :param service: six.string_types. The Ceph user name to run the command under

=== modified file 'tests/contrib/storage/test_linux_ceph.py'
--- tests/contrib/storage/test_linux_ceph.py	2016-02-22 15:18:38 +0000
+++ tests/contrib/storage/test_linux_ceph.py	2016-03-02 18:16:59 +0000
@@ -81,6 +81,32 @@
 }
 """
 
+MONMAP_DUMP = """{
+    "name": "ip-172-31-13-119", "rank": 0, "state": "leader",
+    "election_epoch": 18, "quorum": [0, 1, 2],
+    "outside_quorum": [],
+    "extra_probe_peers": [],
+    "sync_provider": [],
+    "monmap": {
+        "epoch": 1,
+        "fsid": "9fdc313c-db30-11e5-9805-0242fda74275",
+        "modified": "0.000000",
+        "created": "0.000000",
+        "mons": [
+            {
+                "rank": 0,
+                "name": "ip-172-31-13-119",
+                "addr": "172.31.13.119:6789\/0"},
+            {
+                "rank": 1,
+                "name": "ip-172-31-24-50",
+                "addr": "172.31.24.50:6789\/0"},
+            {
+                "rank": 2,
+                "name": "ip-172-31-33-107",
+                "addr": "172.31.33.107:6789\/0"}
+        ]}}"""
+
 CEPH_CLIENT_RELATION = {
     'ceph:8': {
         'ceph/0': {
@@ -386,6 +412,71 @@
         self.check_call.assert_called_with(cmd)
         self.assertEqual(True, profile_exists)
 
+    def test_set_monitor_key(self):
+        cmd = ['ceph', '--id', 'admin',
+               'ceph', 'config-key', 'put', 'foo', 'bar']
+        ceph_utils.monitor_key_set(service='admin', key='foo', value='bar')
+        self.check_output.assert_called_with(cmd)
+
+    def test_get_monitor_key(self):
+        cmd = ['ceph', '--id', 'admin',
+               'ceph', 'config-key', 'get', 'foo']
+        ceph_utils.monitor_key_get(service='admin', key='foo')
+        self.check_output.assert_called_with(cmd)
+
+    def test_get_monitor_key_failed(self):
+        self.check_output.side_effect = CalledProcessError(
+            returncode=2,
+            cmd='ceph',
+            output='key foo does not exist')
+        output = ceph_utils.monitor_key_get(service='admin', key='foo')
+        self.assertEqual(None, output)
+
+    def test_monitor_key_exists(self):
+        cmd = ['ceph', '--id', 'admin',
+               'config-key', 'exists', 'foo']
+        ceph_utils.monitor_key_exists(service='admin', key='foo')
+        self.check_call.assert_called_with(cmd)
+
+    def test_monitor_key_doesnt_exist(self):
+        self.check_call.side_effect = CalledProcessError(
+            returncode=2,
+            cmd='ceph',
+            output='key foo does not exist')
+        output = ceph_utils.monitor_key_exists(service='admin', key='foo')
+        self.assertEqual(False, output)
+
+    def test_delete_monitor_key(self):
+        ceph_utils.monitor_key_delete(service='admin', key='foo')
+        cmd = ['ceph', '--id', 'admin',
+               'ceph', 'config-key', 'del', 'foo']
+        self.check_output.assert_called_with(cmd)
+
+    def test_delete_monitor_key_failed(self):
+        self.check_output.side_effect = CalledProcessError(
+            returncode=2,
+            cmd='ceph',
+            output='deletion failed')
+        self.assertRaises(CalledProcessError, ceph_utils.monitor_key_delete,
+                          service='admin', key='foo')
+
+    def test_get_monmap(self):
+        self.check_output.return_value = MONMAP_DUMP
+        cmd = ['ceph', '--id', 'admin',
+               'ceph', 'mon_status', '--format=json']
+        ceph_utils.get_mon_map(service='admin')
+        self.check_output.assert_called_with(cmd)
+
+    @patch.object(ceph_utils, 'get_mon_map')
+    def test_hash_monitor_names(self, monmap):
+        expected_hash_list = [
+            '010d57d581604d411b315dd64112bff832ab92c7323fa06077134b50',
+            '8e0a9705c1aeafa1ce250cc9f1bb443fc6e5150e5edcbeb6eeb82e3c',
+            'c3f8d36ba098c23ee920cb08cfb9beda6b639f8433637c190bdd56ec']
+        monmap.return_value = json.loads(MONMAP_DUMP)
+        hashed_mon_list = ceph_utils.hash_monitor_names(service='admin')
+        self.assertEqual(expected=expected_hash_list, observed=hashed_mon_list)
+
     def test_get_cache_mode(self):
         self.check_output.return_value = OSD_DUMP
         cache_mode = ceph_utils.get_cache_mode(service='admin', pool_name='rbd')