kubernetes 服务中的多个外部名称以使用连接字符串访问外部远程托管的 mongodb

Question

我想使用 URI 将我的 Kubernetes 部署连接到远程托管的数据库。

我能够使用 Docker 通过 URI 连接到远程托管的数据库。 现在我想了解如何在 Kubernetes 服务文件中指定多个外部名称。

我有一个带有以下 URL 的MongoDB集群：

mongodb://username:password@mngd-new-pr1-01:27017,mngd-new-pr2-02:27017,mngd-new-pr3-03:27017/

我遵循了Kubernetes 最佳实践：映射外部服务。 当我设置单个外部名称时，它正在工作。

如何在外部名称中指定所有 3 个集群？

kind: Service
apiVersion: v1
metadata:
 name: mongo
spec:
  type: ExternalName
  externalName: mngd-new-pr1-01,mngd-new-pr2-02,mngd-new-pr3-03
  ports:
  - port: 27017

因为我无法创建多个外部名称。

我创建了无头服务，然后为该服务创建了端点。如“场景 1：具有 IP 地址的集群外数据库”所述

从日志中，我认为正在建立连接。 但后来出现了如下异常并且断开了连接。

2019-03-20 11:26:13.941 INFO 1 --- [38.200.19:27038] org.mongodb.driver.connection : Opened connection [connectionId{localValue:1, serverValue:386066}] to .38.200.19:27038
2019-03-20 11:26:13.953 INFO 1 --- [.164.29.4:27038] org.mongodb.driver.connection : Opened connection [connectionId{localValue:2, serverValue:458254}] to .164.29.4:27038
2019-03-20 11:26:13.988 INFO 1 --- [38.200.19:27038] org.mongodb.driver.cluster : Monitor thread successfully connected to server with description ServerDescription{address=.38.200.19:27038, type=REPLICA_SET_PRIMARY, state=CONNECTED, ok=true, version=ServerVersion{versionList=[3, 6, 8]}, minWireVersion=0, maxWireVersion=6, maxDocumentSize=16777216, logicalSessionTimeoutMinutes=30, roundTripTimeNanos=45440955, setName='no-prd-rep', canonicalAddress=mngd-new-pr1-01:27038, hosts=[mngd-new-pr1-01:27038, mngd-new-pr1-02:27038, mngd-new-pr1-03:27038], passives=[], arbiters=[], primary='mngd-new-pr1-01:27038'
2019-03-20 11:26:13.990 INFO 1 --- [38.200.19:27038] org.mongodb.driver.cluster : Adding discovered server mngd-new-pr1-01:27038 to client view of cluster
2019-03-20 11:26:13.992 INFO 1 --- [38.200.19:27038] org.mongodb.driver.cluster : Adding discovered server mngd-new-pr1-02:27038 to client view of cluster
2019-03-20 11:26:13.993 INFO 1 --- [38.200.19:27038] org.mongodb.driver.cluster : Adding discovered server mngd-new-pr1-03:27038 to client view of cluster
2019-03-20 11:26:13.997 INFO 1 --- [38.200.19:27038] org.mongodb.driver.cluster : Server 102.227.4:27038 is no longer a member of the replica set. Removing from client view of cluster.
2019-03-20 11:26:14.001 INFO 1 --- [.164.29.4:27038] org.mongodb.driver.cluster : Monitor thread successfully connected to server with description ServerDescription{address=.164.29.4:27038, type=REPLICA_SET_SECONDARY, state=CONNECTED, ok=true, version=ServerVersion{versionList=[3, 6, 8]}, minWireVersion=0, maxWireVersion=6, maxDocumentSize=16777216, logicalSessionTimeoutMinutes=30, roundTripTimeNanos=47581993, setName='no-prd-rep', canonicalAddress=mngd-new-pr1-01:27038, hosts=[mngd-new-pr1-01:27038, mngd-new-pr1-02:27038, mngd-new-pr1-03:27038], passives=[], arbiters=[], primary='mngd-new-pr1-01:27038',
2019-03-20 11:26:14.001 INFO 1 --- [38.200.19:27038] org.mongodb.driver.cluster : Server 38.200.19:27038 is no longer a member of the replica set. Removing from client view of cluster.
2019-03-20 11:26:14.001 INFO 1 --- [38.200.19:27038] org.mongodb.driver.cluster : Server 164.29.4:27038 is no longer a member of the replica set. Removing from client view of cluster.
2019-03-20 11:26:14.001 INFO 1 --- [38.200.19:27038] org.mongodb.driver.cluster : Canonical address mngd-new-pr1-01:27038 does not match server address. Removing .38.200.19:27038 from client view of cluster
2019-03-20 11:26:34.012 INFO 1 --- [2-prd2-01:27038] org.mongodb.driver.cluster : Exception in monitor thread while connecting to server mngd-new-pr1-01:27038
com.mongodb.MongoSocketException: mngd-new-pr1-01: Name or service not known
at com.mongodb.ServerAddress.getSocketAddress(http://ServerAddress.java:188 ) ~[mongodb-driver-core-3.6.4.jar!/:na]

因此，由于我们使用端点作为 ip 地址，并且它与部署 yaml 连接字符串中指定的连接字符串不匹配，因此可能会失败。 真的让我很困惑:)

PS：为了检查与外部 mongo 集群的连接，我启动了单个 pod

apiVersion: v1
kind: Pod
metadata:
  name: proxy-chk
spec:
  containers:
  - name: centos
    image: centos
    command: ["/bin/sh", "-c", "while : ;do curl -L http://${MONGODBendpointipaddress}:27038/; sleep 10; done"]

在日志中，我可以看到它能够建立连接。

" 看起来您正在尝试通过本地驱动程序端口上的 HTTP 访问 MongoDB。"

所以我认为我之前创建的无头服务能够路由流量

需要你的建议。

Answer 1

一种替代方法是为每个 mongo 主机创建一个服务服务，但如果您将来需要添加更多主机，这会破坏抽象。