Change to MongoReplicaSetClient with multiple hosts

- Replace lots of instances of `'localhost'` with `['localhost']`
- Lots of tests hard code this: TODO - change to respect the app.config?

backdrop/admin/app.py

@@ -30,7 +30,7 @@
 app.url_map.converters["bucket"] = BucketConverter
 
 db = database.Database(
-    app.config['MONGO_HOST'],
+    app.config['MONGO_HOSTS'],
     app.config['MONGO_PORT'],
     app.config['DATABASE_NAME']
 )

backdrop/admin/config/development.py

@@ -4,7 +4,7 @@
 SECRET_KEY = "something unique and secret"
 
 DATABASE_NAME = "backdrop"
-MONGO_HOST = 'localhost'
+MONGO_HOSTS = ['localhost']
 MONGO_PORT = 27017
 
 try:

backdrop/admin/config/test.py

@@ -5,7 +5,7 @@
 SECRET_KEY = "something unique and secret"
 
 DATABASE_NAME = "backdrop_test"
-MONGO_HOST = 'localhost'
+MONGO_HOSTS = ['localhost']
 MONGO_PORT = 27017
 
 from test_environment import *

backdrop/core/database.py

@@ -9,9 +9,20 @@
 
 class Database(object):
 
-    def __init__(self, host, port, name):
-        self._mongo = pymongo.MongoReplicaSetClient(host, port,
-                                                    replicaSet='production')
+    def __init__(self, hosts, port, name):
+        """
+        Create a list to feed to the MongoReplicaSetClient in a way it understands
+        e.g. MongoReplicaSetClient(
+            [u'hostname_one:27017', u'hostname_two:27017', u'hostname_three:27017'])
+        See http://api.mongodb.org/python/current/examples/high_availability.html#mongoreplicasetclient for more
+        """
+
+        clientList = []
+        for host in hosts:
+            clientList.append('{0}:{1}'.format(host, port))
+
+        self._mongo = pymongo.MongoReplicaSetClient(
+            ','.join(clientList), replicaSet='production')
         self.name = name
 
     def alive(self):

backdrop/read/api.py

@@ -27,7 +27,7 @@
     "backdrop.read.config.{}".format(GOVUK_ENV))
 
 db = database.Database(
-    app.config['MONGO_HOST'],
+    app.config['MONGO_HOSTS'],
     app.config['MONGO_PORT'],
     app.config['DATABASE_NAME']
 )

backdrop/read/config/development.py

@@ -1,5 +1,5 @@
 DATABASE_NAME = "backdrop"
-MONGO_HOST = 'localhost'
+MONGO_HOSTS = ['localhost']
 MONGO_PORT = 27017
 LOG_LEVEL = "DEBUG"
 RAW_QUERIES_ALLOWED = {

backdrop/read/config/test.py

@@ -1,5 +1,5 @@
 DATABASE_NAME = "backdrop_test"
-MONGO_HOST = 'localhost'
+MONGO_HOSTS = ['localhost']
 MONGO_PORT = 27017
 LOG_LEVEL = "ERROR"
 RAW_QUERIES_ALLOWED = {

backdrop/write/api.py

@@ -27,7 +27,7 @@
     "backdrop.write.config.{}".format(GOVUK_ENV))
 
 db = database.Database(
-    app.config['MONGO_HOST'],
+    app.config['MONGO_HOSTS'],
     app.config['MONGO_PORT'],
     app.config['DATABASE_NAME']
 )

backdrop/write/config/development.py

@@ -1,5 +1,5 @@
 DATABASE_NAME = "backdrop"
-MONGO_HOST = 'localhost'
+MONGO_HOSTS = ['localhost']
 MONGO_PORT = 27017
 LOG_LEVEL = "DEBUG"
 BUCKET_AUTO_ID_KEYS = {

backdrop/write/config/test.py

@@ -1,5 +1,5 @@
 DATABASE_NAME = "backdrop_test"
-MONGO_HOST = 'localhost'
+MONGO_HOSTS = ['localhost']
 MONGO_PORT = 27017
 LOG_LEVEL = "DEBUG"
 CLIENT_ID = "it's not important here"

run_migrations.py

@@ -30,7 +30,8 @@ def load_config(env):
 
 
 def get_database(config):
-    return Database(config.MONGO_HOST, config.MONGO_PORT, config.DATABASE_NAME)
+    return Database(
+        config.MONGO_HOSTS, config.MONGO_PORT, config.DATABASE_NAME)
 
 
 def get_migrations():

tasks.py

@@ -19,7 +19,7 @@ def get_database():
         "backdrop.write.config.%s" % environment()
     )
     return database.Database(
-        app.config['MONGO_HOST'],
+        app.config['MONGO_HOSTS'],
         app.config['MONGO_PORT'],
         app.config['DATABASE_NAME']
     )

tests/core/integration/test_bucket_integration.py

@@ -13,7 +13,7 @@
 from backdrop.read.query import Query
 from tests.support.test_helpers import d_tz
 
-HOST = 'localhost'
+HOST = ['localhost']
 PORT = 27017
 DB_NAME = 'performance_platform_test'
 BUCKET = 'bucket_integration_test'

tests/core/integration/test_database_integration.py

@@ -9,7 +9,7 @@
 from backdrop.read.query import Query
 from tests.support.test_helpers import d, d_tz
 
-HOST = 'localhost'
+HOST = ['localhost']
 PORT = 27017
 DB_NAME = 'performance_platform_test'
 BUCKET = 'test_repository_integration'
@@ -762,7 +762,7 @@ def test_query_map(self):
 
 class TestDatabase(unittest.TestCase):
     def setUp(self):
-        self.db = Database('localhost', 27017, 'backdrop_test')
+        self.db = Database(HOST, PORT, DB_NAME)
         self.db.mongo_database["my_capped_collection"].drop()
 
     def test_alive(self):

tests/core/integration/test_repository.py

@@ -5,7 +5,7 @@
 from backdrop.core.repository import BucketConfigRepository, UserConfigRepository
 from backdrop.core.user import UserConfig
 
-HOST = 'localhost'
+HOST = ['localhost']
 PORT = 27017
 DB_NAME = 'performance_platform_test'
 BUCKET = 'buckets'