如何在 kubernetes 中连接无头 Mongo 服务

Question

apiVersion: v1
kind: Service
metadata:
name: mongo
labels:
name: mongo
spec:
ports:
- port: 27017
targetPort: 27017
clusterIP: None
selector:
name: mongo
---
apiVersion: apps/v1beta1
kind: StatefulSet
metadata:
name: mongo
spec:
serviceName: "mongo"
replicas: 1
template:
metadata:
labels:
name: mongo
#    environment: test
spec:
terminationGracePeriodSeconds: 10
volumes:
- name: mongo-pv-storage
persistentVolumeClaim:
claimName: mongo-pv-claim
containers:
- name: mongo
image: mongo:4.0.12-xenial
command:
- mongod
- "--bind_ip"
- 0.0.0.0
- "--smallfiles"
- "--noprealloc"
ports:
- containerPort: 27017
name: mongo
volumeMounts:
- name: mongo-pv-storage
mountPath: /data/db

我已经使用了上面的yaml。Mongo Db正在运行，使用kubectl exec命令进行了良好检查。下面 yaml 用于部署 spring 启动应用程序。

apiVersion: apps/v1
kind: Deployment
metadata:
name: imageprocessor-app-backend
labels:
app: imageprocessor-app-backend
spec:
# modify replicas according to your case
selector:
matchLabels:
tier: imageprocessor-app-backend
template:
metadata:
labels:
tier: imageprocessor-app-backend
spec:
containers:
- name: imageprocessor-app-backend
image: imageprocessor-app-backend:v1
ports:
- containerPort: 8099
env:
- name: spring.data.mongodb.host
value: mongo-0.mongo
- name: spring.data.mongodb.port
value: "27017"
- name: spring.data.mongodb.database
value: testdb
---
apiVersion: v1
kind: Service
metadata:
name: imageprocessor-app-backend
spec:
type: NodePort
ports:
- port: 8099
nodePort: 31471
selector:
tier: imageprocessor-app-backend

我得到的例外是

2019-09-24 12:27:04.902  INFO 1 --- [o-0.mongo:27017] org.mongodb.driver.cluster               : Exception in monitor thread while connecting to server mongo-0.mongo:27017
com.mongodb.MongoSocketException: mongo-0.mongo: Try again
at com.mongodb.ServerAddress.getSocketAddress(ServerAddress.java:188) ~[mongodb-driver-core-3.8.2.jar:na]
at com.mongodb.internal.connection.SocketStreamHelper.initialize(SocketStreamHelper.java:64) ~[mongodb-driver-core-3.8.2.jar:na]
at com.mongodb.internal.connection.SocketStream.open(SocketStream.java:62) ~[mongodb-driver-core-3.8.2.jar:na]
at com.mongodb.internal.connection.InternalStreamConnection.open(InternalStreamConnection.java:126) ~[mongodb-driver-core-3.8.2.jar:na]
at com.mongodb.internal.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:117) ~[mongodb-driver-core-3.8.2.jar:na]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_212]
Caused by: java.net.UnknownHostException: mongo-0.mongo: Try again
at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method) ~[na:1.8.0_212]
at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:929) ~[na:1.8.0_212]
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1324) ~[na:1.8.0_212]
at java.net.InetAddress.getAllByName0(InetAddress.java:1277) ~[na:1.8.0_212]
at java.net.InetAddress.getAllByName(InetAddress.java:1193) ~[na:1.8.0_212]
at java.net.InetAddress.getAllByName(InetAddress.java:1127) ~[na:1.8.0_212]
at java.net.InetAddress.getByName(InetAddress.java:1077) ~[na:1.8.0_212]
at com.mongodb.ServerAddress.getSocketAddress(ServerAddress.java:186) ~[mongodb-driver-core-3.8.2.jar:na]
... 5 common frames omitted

如何将无头 mongo 服务与我的应用程序连接。我尝试使用 - 名称：spring.data.mongodb.host 值：mongo-0.mongo//和值：mongo

Answer 1

您需要使用服务的名称作为主机名。在您的示例中，它是mongo.我用你上面的 YAML 部署了 mongo，我可以从同一命名空间中的另一个 pod 成功连接到它。

如果您在不同的命名空间中运行imageprocessor-app-backend，则mongo，则必须将运行mongo的命名空间添加到主机名中：mongo.<namespace>，例如mongo.mongo.