Added KVM Metric plugin (#2)

This plugin will pull metrics and meta-data from a KVM host.

Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>

AUTHORS

@@ -1,2 +1,2 @@
-Kevin Carter <kevin.carter@rackspace.com>
+Kevin Carter <kevin@cloudnull.com>
 Major Hayden <major@mhtx.net>

ChangeLog

@@ -1,6 +1,7 @@
 CHANGES
 =======
 
+* Added KVM Metric plugin
 * Couple of updates: telegraf line protocol, dynamic imports, metadata
 * Proof of concept
 * Initial commit

monitorstack/plugins/kvm.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+# Copyright 2017, Kevin Carter <kevin@cloudnull.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import platform
+import socket
+
+import click
+
+from monitorstack.cli import pass_context
+
+
+DOC = """Get metrics from a KVM hypervisor"""
+
+
+@click.command('kvm', short_help=DOC.split('\n')[0])
+@pass_context
+def cli(ctx):
+    setattr(cli, '__doc__', DOC)
+
+    # Lower level import because we only want to load this module
+    #  when this plugin is called.
+    try:
+        import libvirt
+    except ImportError:
+        raise SystemExit('The "kvm plugin requires libvirt-python to be'
+                         ' installed".')
+
+    output = {
+        'measurement_name': 'kvm',
+        'meta': {
+            'platform': platform.platform(),
+            'kvm_host_id': abs(hash(socket.getfqdn()))
+        }
+    }
+    conn = libvirt.openReadOnly()
+    try:
+        variables = output['variables'] = dict()
+        domains = conn.listDomainsID()
+        variables['kvm_vms'] = len(domains)
+        variables['kvm_total_vcpus'] = conn.getCPUMap()[0]
+        variables['kvm_scheduled_vcpus'] = 0
+        for domain in domains:
+            variables['kvm_scheduled_vcpus'] += conn.lookupByID(
+                domain
+            ).maxVcpus()
+
+    except Exception as exp:
+        output['exit_code'] = 1
+        output['message'] = 'kvm failed -- Error: {}'.format(exp)
+    else:
+        output['exit_code'] = 0
+        output['message'] = 'kvm is ok'
+    finally:
+        conn.close()
+        return output

tests/test_kvm.py

@@ -0,0 +1,71 @@
+# Copyright 2017, Kevin Carter <kevin@cloudnull.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests for the base class."""
+
+import json
+import sys
+
+from click.testing import CliRunner
+
+from monitorstack.cli import cli
+
+
+class LibvirtStub(object):
+    """Stubbed libvirt class."""
+
+    class openReadOnly(object):  # noqa
+        """Stubbed openReadOnly class."""
+
+        def close(self, *args, **kwargs):  # noqa
+            pass
+
+        def listDomainsID(self, *args, **kwargs):  # noqa
+            return ['a', 'b', 'c']
+
+        def getCPUMap(self, *args, **kwargs):  # noqa
+            return [1, 1, 1]
+
+        class lookupByID(object):  # noqa
+            """Stubbed lookupByID class."""
+            def __init__(self, *args, **kwargs):
+                pass
+
+            def maxVcpus(self):  # noqa
+                return 2
+
+
+class TestKvm(object):
+    """Tests for the uptime monitor class."""
+
+    def test_run(self):
+        """Ensure the run() method works."""
+
+        sys.modules['libvirt'] = LibvirtStub
+
+        runner = CliRunner()
+        result = runner.invoke(cli, ['-f', 'json', 'kvm'])
+        result_json = json.loads(result.output)
+
+        variables = result_json['variables']
+        meta = result_json['meta']
+        assert 'kvm_vms' in variables
+        assert variables['kvm_vms'] == 3
+        assert 'kvm_total_vcpus' in variables
+        assert variables['kvm_total_vcpus'] == 1
+        assert 'kvm_scheduled_vcpus' in variables
+        assert variables['kvm_scheduled_vcpus'] == 6
+        assert 'platform' in meta
+        assert 'kvm_host_id' in meta
+        assert result.exit_code == 0