Add graphite metrics API

Author: countsudoku

docs/source/text/data_access.rst

@@ -8,6 +8,7 @@ Graphite
 
 .. autoclass:: GraphiteReader
     :members:
+    :inherited-members:
 
 PNP4nagios
 ----------

pandas_metricsreader/graphite/graphite.py

@@ -9,9 +9,10 @@
 from pandas import read_csv, MultiIndex, concat, DataFrame, to_datetime
 from pandas.compat import StringIO, string_types
 
-from pandas_metricsreader.BaseReader import BaseReader, MetricsReaderError
+from pandas_metricsreader.BaseReader import MetricsReaderError
+from .metricsAPI import GraphiteMetricsAPI
 
-class GraphiteReader(BaseReader):
+class GraphiteReader(GraphiteMetricsAPI):
     """
     Creates a GraphiteDataReader object, which you can use to read different
     metrics in a pandas DataFrame

pandas_metricsreader/graphite/metricsAPI.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+""" A class, which implements the metric API of graphite """
+
+from __future__ import print_function, absolute_import
+
+import os
+import urlparse
+
+from pandas_metricsreader.BaseReader import BaseReader
+
+class GraphiteMetricsAPI(BaseReader):
+    """
+    Creates a GraphiteMetricAPI object, which you can use to request, which
+    metrics are available in the graphite cluster
+
+    Arguments:
+        url: string
+            the base url to the Graphite host
+        tls_verify: string or bool
+            enable or disable certificate validation. You can als specify the
+            path to a certificate or a directory, which must have been
+            processed using the c_rehash utily supplied with OppenSSL
+            (default: True)
+        session: a requests.Session object (default None)
+        timeout: float or tuple
+    """
+
+    def __init__(self,
+                 url,
+                 tls_verify='/etc/ssl/certs/',
+                 session=None,
+                 timeout=30,
+                ):
+        self._metrics_api = '/metrics'
+
+        super(GraphiteMetricsAPI, self).__init__(
+            url=url,
+            tls_verify=tls_verify,
+            session=session,
+            timeout=timeout,
+            )
+
+    def find(self, target, start=None, end=None):
+        """
+        Finds metrics under a given path.
+        """
+        url_path = os.path.join(self._metrics_api, 'find')
+        url = urlparse.urljoin(self.url, url_path)
+        params = { 'query': target,
+                   'formater': 'treejson',
+                   'from': start,
+                   'until': end,
+                   'wildcards': 0,
+                 }
+        r = self._get(url, params=params)
+        return r.json()
+
+    def expand(self, targets, group_by_expr=False, leaves_only=False):
+        """
+        Expands the given query with matching paths.
+        """
+        if not isinstance(group_by_expr, bool):
+            raise TypeError('group_by_expr has to be of type bool')
+        if not isinstance(leaves_only, bool):
+            raise TypeError('leaves_only has to be of type bool')
+
+        if group_by_expr:
+            group_by_expr = 1
+        else:
+            group_by_expr = 0
+
+        if leaves_only:
+            leaves_only = 1
+        else:
+            leaves_only = 0
+
+        url_path = os.path.join(self._metrics_api, 'expand')
+        url = urlparse.urljoin(self.url, url_path)
+        params = { 'query': targets,
+                   'groupByExpr':group_by_expr,
+                   'leavesOnly':leaves_only,
+                 }
+        r = self._get(url, params=params)
+        return r.json()['results']
+
+    def index(self):
+        """
+        Walks the metrics tree and returns every metric found as a sorted JSON
+        array.
+        """
+        raise NotImplementedError
+
+if __name__ == "__main__":
+    print(__doc__)