Get rid from some stupid logic with options=True/False

And some other tricks with overriding handle_one_request and finish
methods from the parent class which were necessary only to make OPTIONS
request from haproxy work with python2, but in fact it was still not
working with python3. Instead of doing all the magic we should simply
give to haproxy what it wants to get: HTTP response code and nothing
more.

patroni/api.py

@@ -3,7 +3,6 @@ import fcntl
 import json
 import logging
 import psycopg2
-import socket
 import time
 import dateutil
 import datetime
@@ -36,14 +35,13 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
     def _write_response(self, status_code, body, content_type='text/html', headers=None):
         self.send_response(status_code)
-        if body is not None:
-            headers = headers or {}
-            if content_type:
-                headers['Content-Type'] = content_type
-            for name, value in headers.items():
-                self.send_header(name, value)
-            self.end_headers()
-            self.wfile.write(body.encode('utf-8'))
+        headers = headers or {}
+        if content_type:
+            headers['Content-Type'] = content_type
+        for name, value in headers.items():
+            self.send_header(name, value)
+        self.end_headers()
+        self.wfile.write(body.encode('utf-8'))
 
     def _write_json_response(self, status_code, response):
         self._write_response(status_code, json.dumps(response), content_type='application/json')
@@ -52,23 +50,12 @@ class RestApiHandler(BaseHTTPRequestHandler):
         headers = {'WWW-Authenticate': 'Basic realm="' + self.server.patroni.__class__.__name__ + '"'}
         self._write_response(401, body, headers=headers)
 
-    def finish(self):
-        try:
-            if not self.wfile.closed:
-                self.wfile.flush()
-                self.wfile.close()
-        except socket.error:
-            pass
-        self.rfile.close()
-
     def check_auth_header(self):
         auth_header = self.headers.get('Authorization')
         status = self.server.check_auth_header(auth_header)
         return not status or self.send_auth_request(status)
 
-    def _write_status_response(self, status_code, response, only_status_code=False):
-        if only_status_code:
-            return self._write_response(status_code, None)
+    def _write_status_response(self, status_code, response):
         patroni = self.server.patroni
         response.update({'tags': patroni.tags} if patroni.tags else {})
         if patroni.postgresql.sysid:
@@ -78,7 +65,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
         response['patroni'] = {'version': patroni.version, 'scope': patroni.postgresql.scope}
         self._write_json_response(status_code, response)
 
-    def do_GET(self, only_status_code=False):
+    def do_GET(self, write_status_code_only=False):
         """Default method for processing all GET requests which can not be routed to other methods"""
 
         path = '/master' if self.path == '/' else self.path
@@ -104,10 +91,15 @@ class RestApiHandler(BaseHTTPRequestHandler):
             status_code = 200
         else:
             status_code = 503
-        self._write_status_response(status_code, response, only_status_code)
+
+        if write_status_code_only:  # when haproxy sends OPTIONS request it reads only statue code and nothing more
+            message = self.responses[status_code][0]
+            self.wfile.write(("%s %d %s\r\n" % (self.protocol_version, status_code, message)).encode('utf-8'))
+        else:
+            self._write_status_response(status_code, response)
 
     def do_OPTIONS(self):
-        self.do_GET(only_status_code=True)
+        self.do_GET(write_status_code_only=True)
 
     def do_GET_patroni(self):
         response = self.get_postgresql_status(True)
@@ -285,12 +277,6 @@ class RestApiHandler(BaseHTTPRequestHandler):
                 self.command = mname
         return ret
 
-    def handle_one_request(self):
-        try:
-            BaseHTTPRequestHandler.handle_one_request(self)
-        except socket.error:
-            pass
-
     def query(self, sql, *params, **kwargs):
         if not kwargs.get('retry', False):
             return self.server.query(sql, *params)

tests/test_api.py

@@ -1,5 +1,4 @@
 import psycopg2
-import socket
 import unittest
 
 from mock import Mock, patch
@@ -7,7 +6,6 @@ from patroni.api import RestApiHandler, RestApiServer
 from patroni.dcs import ClusterConfig, Member
 from six import BytesIO as IO
 from six.moves import BaseHTTPServer
-from six.moves.BaseHTTPServer import BaseHTTPRequestHandler
 from test_postgresql import psycopg2_connect, MockCursor
 
 
@@ -111,17 +109,6 @@ class TestRestApiHandler(unittest.TestCase):
     def test_do_OPTIONS(self):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'OPTIONS / HTTP/1.0'))
 
-        with patch.object(BaseHTTPRequestHandler, 'handle_one_request') as mock_handle_request:
-            mock_handle_request.side_effect = socket.error("foo")
-            MockRestApiServer(RestApiHandler, 'OPTIONS / HTTP/1.0')
-
-        # make sure socket.error gets propagated via wfile object in finalize()
-        with patch.object(MockRequest, 'makefile') as makefile:
-            makefile.return_value.closed = False
-            makefile.return_value.readline = Mock(return_value=b'foo')
-            makefile.return_value.flush = Mock(side_effect=socket.error('foo'))
-            MockRestApiServer(RestApiHandler, 'OPTIONS / HTTP/1.0')
-
     def test_do_GET_patroni(self):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /patroni'))