Python cleanup: make nosetests the default test runner, coverage, fla…

…ke8 (#417)

* Upstream seems to prefer nosetests

* Make requirements-dev.txt include requirements.txt

* Report coverage after builds

* Run flake8 after builds

* test_marathon_lb_haproxy_options: Remove unused imports

* Fix simple flake8 violations

* Fix ip_cache size setting

* flake8 now passes

README.md

@@ -359,8 +359,8 @@ PRs are welcome, but here are a few general guidelines:
  - Update/include tests for new functionality. To install dependencies and run tests:
 
    ```
-   pip install -r requirements.txt -r requirements-dev.txt
-   pytest --pep8 --cov
+   pip install -r requirements-dev.txt
+   nosetests
    ```
  - Use the pre-commit hook to automatically generate docs:
 

build.bash

@@ -8,6 +8,10 @@ else
   PIPCMD='pip3'
 fi
 
-$PIPCMD install -r requirements.txt -r requirements-dev.txt nose
+$PIPCMD install -r requirements-dev.txt
 
-PYTHONPATH=. nosetests
+PYTHONPATH=. coverage run "$(which nosetests)"
+
+coverage report
+
+flake8 .

config.py

@@ -1199,6 +1199,7 @@ def __init__(self, name, func, description, perServicePort=True):
         self.func = func
         self.description = description
 
+
 labels = []
 labels.append(Label(name='AUTH',
                     func=set_auth,

haproxy_wrapper.py

@@ -34,6 +34,7 @@ def wait_on_haproxy_pipe(pipefd):
             return False
     return True
 
+
 pipefd = create_haproxy_pipe()
 
 pid = os.fork()

marathon_lb.py

@@ -41,14 +41,13 @@
 
 import dateutil.parser
 import requests
-from six.moves.urllib import parse
 
 from common import (get_marathon_auth_params, set_logging_args,
                     set_marathon_auth_args, setup_logging)
 from config import ConfigTemplater, label_keys
 from lrucache import LRUCache
-from utils import (CurlHttpEventStream, get_task_ip_and_ports,
-                   ServicePortAssigner, set_ip_cache)
+from utils import (CurlHttpEventStream, get_task_ip_and_ports, ip_cache,
+                   ServicePortAssigner)
 
 
 logger = logging.getLogger('marathon_lb')
@@ -1213,6 +1212,7 @@ def get_health_check(app, portIndex):
             return check
     return None
 
+
 healthCheckResultCache = LRUCache()
 
 
@@ -1719,7 +1719,7 @@ def process_sse_events(marathon, processor):
     # initialize health check LRU cache
     if args.health_check:
         healthCheckResultCache = LRUCache(args.lru_cache_capacity)
-    set_ip_cache(LRUCache(args.lru_cache_capacity))
+    ip_cache.set(LRUCache(args.lru_cache_capacity))
 
     # Marathon API connector
     marathon = Marathon(args.marathon,

requirements-dev.txt

@@ -1,4 +1,5 @@
+-r requirements.txt
+coverage
+flake8
 mock
-pytest
-pytest-cov
-pytest-pep8
+nose

tests/test_marathon_lb_haproxy_options.py

@@ -1,9 +1,5 @@
-import copy
-import json
-import unittest
 import os
 
-import marathon_lb
 from tests.test_marathon_lb import TestMarathonUpdateHaproxy
 
 

utils.py

@@ -221,7 +221,7 @@ def iter_lines(self):
 
     @staticmethod
     def _split_lines_from_chunks(chunks):
-        #same behaviour as requests' Response.iter_lines(...)
+        # same behaviour as requests' Response.iter_lines(...)
 
         pending = None
         for chunk in chunks:
@@ -243,22 +243,33 @@ def _split_lines_from_chunks(chunks):
 
 
 def resolve_ip(host):
-    cached_ip = ip_cache.get(host, None)
+    cached_ip = ip_cache.get().get(host, None)
     if cached_ip:
         return cached_ip
     else:
         try:
             logger.debug("trying to resolve ip address for host %s", host)
             ip = socket.gethostbyname(host)
-            ip_cache.set(host, ip)
+            ip_cache.get().set(host, ip)
             return ip
         except socket.gaierror:
             return None
-ip_cache = LRUCache()
 
 
-def set_ip_cache(new_ip_cache):
-    ip_cache = new_ip_cache
+class LRUCacheSingleton(object):
+    def __init__(self):
+        self.lru_cache = None
+
+    def get(self):
+        if self.lru_cache is None:
+            self.lru_cache = LRUCache()
+        return self.lru_cache
+
+    def set(self, lru_cache):
+        self.lru_cache = lru_cache
+
+
+ip_cache = LRUCacheSingleton()
 
 
 def is_ip_per_task(app):