Add logging when a server is added to haproxy

Author: pawelcodilime

scripts/haproxy/haproxy.py

@@ -11,13 +11,17 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 ###############################################################################
-
+import csv
 import os
+import random
 import subprocess
 import tempfile
+from StringIO import StringIO
 from contextlib import contextmanager
 
+import time
 from jinja2 import Template
+import requests
 
 from cloudify_rest_client import exceptions as rest_exceptions
 from cloudify import ctx
@@ -58,18 +62,36 @@ def configure(subject=None):
 
 
 def add_backend(port, maxconn, backend_address=None):
+    time.sleep(random.randint(0, 5))
+    backends_before = len(_read_haproxy_stats())
+    ctx.logger.info('backends before adding {} ({})'.format(backends_before, time.time()))
+
     with _backends_update() as backends:
         backends[ctx.source.instance.id] = {
             'address': backend_address or ctx.source.instance.host_ip,
             'port': port,
             'maxconn': maxconn
         }
 
+    time.sleep(10)
+
+    backends_after = len(_read_haproxy_stats())
+    ctx.logger.info('backends after adding {} ({})'.format(backends_after, time.time()))
+
 
 def remove_backend():
+    time.sleep(random.randint(0, 5))
+    backends_before = len(_read_haproxy_stats())
+    ctx.logger.info('backends before removing {} ({})'.format(backends_before, time.time()))
+
     with _backends_update() as backends:
         backends.pop(ctx.source.instance.id, None)
 
+    time.sleep(10)
+
+    backends_after = len(_read_haproxy_stats())
+    ctx.logger.info('backends after removing {} ({})'.format(backends_after, time.time()))
+
 
 @contextmanager
 def _backends_update():
@@ -94,6 +116,21 @@ def _backends_update():
             raise
 
 
+def _read_haproxy_stats():
+    csv_data = requests.get(
+        'http://localhost:9000/haproxy_stats;csv',
+        auth=('admin', 'password')).text
+    buff = StringIO(csv_data)
+    parsed_csv_data = list(csv.reader(buff))
+    headers = parsed_csv_data[0]
+    structured_csv_data = [dict(zip(headers, row))
+                           for row in parsed_csv_data]
+    return dict([(struct['svname'], int(struct['stot']))
+                 for struct in structured_csv_data
+                 if struct['# pxname'] == 'servers' and
+                 struct['svname'] != 'BACKEND'])
+
+
 def start():
     _service('start')