Merge pull request #172 from librato/inherit-tags

add ability to inherit tags

Author: mbeale

README.md

@@ -168,11 +168,43 @@ with api.new_queue() as q:
 Queues by default will collect metrics until they are told to submit. You may create a queue
 that autosubmits based on metric volume.
 
+
 ```python
 # Submit when the 400th metric is queued
 q = api.new_queue(auto_submit_count=400)
 ```
 
+## Tag Inheritance
+
+Tags can be inherited from the queue or connection object if `inherit_tags=True` is passed as
+an attribute.  If inherit_tags is not passed, but tags are added to the measurement, the measurement
+tags will be the only tags added to that measurement.  
+
+When there are tag collisions, the measurement, then the batch, then the connection is the order of
+priority.
+
+```python
+api = librato.connect('email', 'token', tags={'company': 'librato', 'service': 'app'})
+
+# tags will be {'city': 'sf'}
+api.submit('temperature', 80, tags={'city': 'sf'})
+
+# tags will be {'city': 'sf', 'company': 'librato', 'service': 'app'}
+api.submit('temperature', 80, tags={'city': 'sf'}, inherit_tags=True)
+
+q = api.new_queue(tags={'service':'api'})
+
+# tags will be {'location': 'downstairs'} 
+q.add('temperature', 22.1, tags={'location': 'downstairs'})
+
+# tags will be {'company': 'librato', 'service':'api'}
+q.add('temperature', 23.1)
+
+# tags will be {'location': 'downstairs', 'company': 'librato', 'service': 'api'}
+q.add('temperature', 22.1, tags={'location': 'downstairs'}, inherit_tags=True)
+q.submit()
+```
+
 ## Updating Metric Attributes
 
 You can update the information for a metric by using the `update` method,

librato/__init__.py

@@ -284,19 +284,26 @@ def submit(self, name, value, type="gauge", **query_props):
 
     def submit_tagged(self, name, value, **query_props):
         payload = {'measurements': []}
+        payload['measurements'].append(self.create_tagged_payload(name, value, **query_props))
+        self._mexe("measurements", method="POST", query_props=payload)
 
-        if self.tags:
-            payload['tags'] = self.tags
-
+    def create_tagged_payload(self, name, value, **query_props):
+        """Create the measurement for forwarding to Librato"""
         measurement = {
             'name': self.sanitize(name),
             'value': value
         }
+        if 'tags' in query_props:
+            inherit_tags = query_props.pop('inherit_tags', False)
+            if inherit_tags:
+                tags = query_props.pop('tags', {})
+                measurement['tags'] = dict(self.get_tags(), **tags)
+        elif self.tags:
+            measurement['tags'] = self.tags
+
         for k, v in query_props.items():
             measurement[k] = v
-
-        payload['measurements'].append(measurement)
-        self._mexe("measurements", method="POST", query_props=payload)
+        return measurement
 
     def get(self, name, **query_props):
         resp = self._mexe("metrics/%s" % self.sanitize(name), method="GET", query_props=query_props)
@@ -561,13 +568,7 @@ def delete_chart(self, chart_id, space_id, **query_props):
     # Queue
     #
     def new_queue(self, **kwargs):
-        tags = self.tags
-        if 'tags' in kwargs:
-            # Supplied tag set takes precedence
-            tags.update(kwargs.pop('tags'))
-
-        q = Queue(self, tags=tags, **kwargs)
-        return q
+        return Queue(self, **kwargs)
 
     #
     # misc

librato/queue.py

@@ -63,10 +63,8 @@ def add_tags(self, d):
         self.tags.update(d)
 
     def add(self, name, value, type='gauge', **query_props):
-        if len(self.tags) > 0:
-            query_props['tags'] = self.tags
-
-        if 'tags' in query_props:
+        """add measurements to the Q"""
+        if 'tags' in query_props or len(self.tags) > 0:
             self.add_tagged(name, value, **query_props)
         else:
             nm = {}  # new measurement
@@ -85,6 +83,13 @@ def add_tagged(self, name, value, **query_props):
         nm['sum'] = value
         nm['count'] = 1
 
+        # must remove the inherit_tags key for compliance with json
+        inherit_tags = query_props.pop('inherit_tags', False)
+        tags = query_props.get('tags', {})
+        if inherit_tags or tags == {}:
+            inheritted_tags = dict(self.connection.get_tags(), **self.get_tags())
+            query_props['tags'] = dict(inheritted_tags, **tags)
+
         for pn, v in query_props.items():
             nm[pn] = v
 
@@ -134,12 +139,8 @@ def submit(self):
             self.connection._mexe("metrics", method="POST", query_props=c)
         self.chunks = []
 
-        for c in self.tagged_chunks:
-            if 'tags' in c:
-                c['tags'] = dict(self.tags).update(c['tags'])
-            elif self.tags:
-                c['tags'] = dict(self.tags)
-            self.connection._mexe("measurements", method="POST", query_props=c)
+        for chunk in self.tagged_chunks:
+            self.connection._mexe("measurements", method="POST", query_props=chunk)
         self.tagged_chunks = []
 
     def __enter__(self):

tests/test_metrics.py

@@ -197,6 +197,20 @@ def test_add_in_gauge(self):
         assert len(gauge.measurements[src]) == 2
         assert gauge.measurements[src][-1]['value'] == 1
 
+    def test_md_inherit_tags(self):
+        self.conn.set_tags({'company': 'Librato', 'hi': 'four'})
+
+        measurement = self.conn.create_tagged_payload('user_cpu', 20.2, tags={'hi': 'five'}, inherit_tags=True)
+
+        assert measurement['tags'] == {'hi': 'five', 'company': 'Librato'}
+
+    def test_md_donot_inherit_tags(self):
+        self.conn.set_tags({'company': 'Librato', 'hi': 'four'})
+
+        measurement = self.conn.create_tagged_payload('user_cpu', 20.2, tags={'hi': 'five'})
+
+        assert measurement['tags'] == {'hi': 'five'}
+
     def test_md_submit(self):
         mt1 = int(time.time()) - 5
 
@@ -223,7 +237,7 @@ def test_merge_tags(self):
 
         self.conn.set_tags({'company': 'Librato'})
         tags = {'hostname': 'web-1'}
-        self.conn.submit_tagged('user_cpu', 20.2, time=mt1, tags=tags)
+        self.conn.submit_tagged('user_cpu', 20.2, time=mt1, tags=tags, inherit_tags=True)
 
         # Ensure 'company' and 'hostname' tags made it through
         for tags_search in ["hostname=web-1", "company=Librato"]:

tests/test_queue.py

@@ -43,6 +43,56 @@ def test_inherited_tags(self):
         assert len(measurements) == 1
         assert measurements[0]['value'] == 10
 
+    def test_inherit_connection_level_tags(self):
+        """test if top level tags are ignored when passing measurement level tags"""
+        conn = librato.connect('user_test', 'key_test', tags={'sky': 'blue'})
+
+        q = conn.new_queue()
+        q.add_tagged('user_cpu', 10, tags={"hi": "five"}, inherit_tags=True)
+
+        measurements = q.tagged_chunks[0]['measurements']
+
+        assert len(measurements) == 1
+        assert measurements[0].get('tags', {}) == {'sky': 'blue', 'hi': 'five'}
+
+    def test_ignore_connection_queue_level_tags(self):
+        """test if queue level tags are ignored when passing measurement level tags"""
+        conn = librato.connect('user_test', 'key_test', tags={'sky': 'blue'})
+
+        q = conn.new_queue(tags={"service": "api"})
+        q.add_tagged('user_cpu', 10, tags={"hi": "five"})
+        measurements = q.tagged_chunks[0]['measurements']
+
+        assert len(measurements) == 1
+        assert measurements[0].get('tags', {}) == {'hi': 'five'}
+
+        q.submit()
+
+        resp = self.conn.get_tagged('user_cpu', duration=60, tags_search="sky=blue")
+        assert len(resp['series']) == 0
+
+    def test_inherit_queue_connection_level_tags(self):
+        """test if queue level tags are ignored when passing measurement level tags"""
+        conn = librato.connect('user_test', 'key_test', tags={'sky': 'blue', 'company': 'Librato'})
+
+        q = conn.new_queue(tags={"service": "api", "hi": "four", "sky": "red"})
+        q.add_tagged('user_cpu', 100, tags={"hi": "five"}, inherit_tags=True)
+        measurements = q.tagged_chunks[0]['measurements']
+
+        assert len(measurements) == 1
+        assert measurements[0].get('tags', {}) == {'sky': 'red', 'service': 'api', 'hi': 'five', 'company': 'Librato'}
+
+    def test_inherit_queue_level_tags(self):
+        """test if queue level tags are ignored when passing measurement level tags"""
+        conn = librato.connect('user_test', 'key_test')
+
+        q = conn.new_queue(tags={"service": "api", "hi": "four"})
+        q.add_tagged('user_cpu', 100, tags={"hi": "five"}, inherit_tags=True)
+        measurements = q.tagged_chunks[0]['measurements']
+
+        assert len(measurements) == 1
+        assert measurements[0].get('tags', {}) == {'service': 'api', 'hi': 'five'}
+
     def test_constructor_tags(self):
         conn = librato.connect('user_test', 'key_test', tags={'sky': 'blue'})
         q = conn.new_queue(tags={'sky': 'red', 'coal': 'black'})
@@ -243,7 +293,7 @@ def test_md_measurement_level_tag(self):
         q.set_tags({'hostname': 'web-1'})
 
         mt1 = int(time.time()) - 5
-        q.add_tagged('system_cpu', 33.22, time=mt1, tags={"user": "james"})
+        q.add_tagged('system_cpu', 33.22, time=mt1, tags={"user": "james"}, inherit_tags=True)
         q.submit()
 
         # Ensure both tags get submitted