From e863046bcef9a7c909d177a93b933e7574317e0c Mon Sep 17 00:00:00 2001
From: Pratyus Patnaik <pratyus.patnaik@gmail.com>
Date: Wed, 18 Oct 2017 13:40:47 -0700
Subject: [PATCH 1/3] Added ability to access mongo oplog via mongos
 router/proxy

---
 mongo_connector/connector.py | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/mongo_connector/connector.py b/mongo_connector/connector.py
index 7465b6d4..ebdf10c9 100644
--- a/mongo_connector/connector.py
+++ b/mongo_connector/connector.py
@@ -124,6 +124,9 @@ def __init__(self, mongo_address, doc_managers=None, **kwargs):
         # Timezone awareness
         self.tz_aware = kwargs.get('tz_aware', False)
 
+        # If connecting to mongos router for oplog access
+        self.is_oplog_proxy= kwargs.get('is_oplog_proxy', False)
+
         # SSL keyword arguments to MongoClient.
         ssl_certfile = kwargs.pop('ssl_certfile', None)
         ssl_ca_certs = kwargs.pop('ssl_ca_certs', None)
@@ -215,7 +218,8 @@ def from_config(cls, config):
             ssl_keyfile=config['ssl.sslKeyfile'],
             ssl_ca_certs=config['ssl.sslCACerts'],
             ssl_cert_reqs=config['ssl.sslCertificatePolicy'],
-            tz_aware=config['timezoneAware']
+            tz_aware=config['timezoneAware'],
+            is_oplog_proxy=config['isOplogProxy']
         )
         return connector
 
@@ -374,12 +378,12 @@ def run(self):
                 )
                 return
 
-            # Establish a connection to the replica set as a whole
-            self.main_conn.close()
-            self.main_conn = self.create_authed_client(
-                replicaSet=is_master['setName'])
-
-            self.update_version_from_client(self.main_conn)
+            if not self.is_oplog_proxy:
+                # Establish a connection to the replica set as a whole
+                self.main_conn.close()
+                self.main_conn = self.create_authed_client(
+                    replicaSet=is_master['setName'])
+                self.update_version_from_client(self.main_conn)
 
             # non sharded configuration
             oplog = OplogThread(
@@ -486,6 +490,16 @@ def add_option(*args, **kwargs):
         " would be a valid argument to `-m`. Don't use"
         " quotes around the address.")
 
+    is_oplog_proxy = add_option(
+        config_key="isOplogProxy",
+        default=False,
+        type=bool)
+
+    is_oplog_proxy.add_cli(
+        "--is_oplog_proxy", dest="is_oplog_proxy", help=
+        "True if passing uri to mongos router/proxy with access"
+        "to mongo oplog.rs.")
+
     oplog_file = add_option(
         config_key="oplogFile",
         default="oplog.timestamp",

From da7bb64f7bd3055d8278188d7409207dcdac1bd0 Mon Sep 17 00:00:00 2001
From: Pratyus Patnaik <pratyus.patnaik@gmail.com>
Date: Wed, 18 Oct 2017 16:01:49 -0700
Subject: [PATCH 2/3] Added check to verify local.oplog.rs is readable

---
 mongo_connector/connector.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/mongo_connector/connector.py b/mongo_connector/connector.py
index ebdf10c9..6fdf8019 100644
--- a/mongo_connector/connector.py
+++ b/mongo_connector/connector.py
@@ -384,6 +384,13 @@ def run(self):
                 self.main_conn = self.create_authed_client(
                     replicaSet=is_master['setName'])
                 self.update_version_from_client(self.main_conn)
+            else:
+                try:
+                    # Check if local.oplog.rs is readable
+                    self.main_conn.local.oplog.rs.find_one()
+                except pymongo.errors.OperationFailure:
+                    LOG.error('Could not read local.oplog.rs!')
+                    sys.exit(1)
 
             # non sharded configuration
             oplog = OplogThread(

From 50f02cb5906cb6dbcc4c2e04a0b5c9ee5c0faaca Mon Sep 17 00:00:00 2001
From: Pratyus Patnaik <pratyus.patnaik@gmail.com>
Date: Thu, 19 Oct 2017 13:37:46 -0700
Subject: [PATCH 3/3] Updated comment wording

---
 mongo_connector/connector.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mongo_connector/connector.py b/mongo_connector/connector.py
index 6fdf8019..bb516598 100644
--- a/mongo_connector/connector.py
+++ b/mongo_connector/connector.py
@@ -124,7 +124,7 @@ def __init__(self, mongo_address, doc_managers=None, **kwargs):
         # Timezone awareness
         self.tz_aware = kwargs.get('tz_aware', False)
 
-        # If connecting to mongos router for oplog access
+        # If oplog access is via the proxy
         self.is_oplog_proxy= kwargs.get('is_oplog_proxy', False)
 
         # SSL keyword arguments to MongoClient.
@@ -504,8 +504,8 @@ def add_option(*args, **kwargs):
 
     is_oplog_proxy.add_cli(
         "--is_oplog_proxy", dest="is_oplog_proxy", help=
-        "True if passing uri to mongos router/proxy with access"
-        "to mongo oplog.rs.")
+        "True if passed uri is a proxy with access to mongo"
+        "oplog.rs.")
 
     oplog_file = add_option(
         config_key="oplogFile",