我有一个带有多个Java微服务的Kubernetes集群，需要连接到远程Kafka集群。服务器位于DigitalOcean中，并且在其专用网络中完全可以访问。 Kafka群集不使用Kubernetes，并且不在群集内。
我使用kubeadm启动了整个集群，这是有关集群的信息:
# kubectl cluster-info
Kubernetes master is running at https://10.132.113.68:6443
KubeDNS is running at https://10.132.113.68:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
集群版本
# kubectl version
Client Version: version.Info{Major:"1", Minor:"10", GitVersion:"v1.10.2", GitCommit:"81753b10df112992bf51bbc2c2f85208aad78335", GitTreeState:"clean", BuildDate:"2018-04-27T09:22:21Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"9", GitVersion:"v1.9.7", GitCommit:"dd5e1a2978fd0b97d9b78e1564398aeea7e7fe92", GitTreeState:"clean", BuildDate:"2018-04-18T23:58:35Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}
这是用来建立网络的:
kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=10.132.113.68 --kubernetes-version stable-1.8
所有 pods 均成功启动:
# kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
default datadog-agent-5cht2 1/1 Running 0 12d
default datadog-agent-5r7rw 1/1 Running 0 12d
default datadog-agent-b7t5q 1/1 Running 0 12d
default vizix-services-7bdccb48c4-2q8js 1/1 Running 0 19m
default vizix-tools-cpr88 0/1 Completed 0 12d
kube-system etcd-kubctl-s-2vcpu-4gb-nyc3-01-master 1/1 Running 0 27d
kube-system kube-apiserver-kubctl-s-2vcpu-4gb-nyc3-01-master 1/1 Running 0 27d
kube-system kube-controller-manager-kubctl-s-2vcpu-4gb-nyc3-01-master 1/1 Running 0 27d
kube-system kube-dns-6f4fd4bdf-f7ssn 3/3 Running 0 27d
kube-system kube-flannel-ds-dm5w4 1/1 Running 0 27d
kube-system kube-flannel-ds-ns58w 1/1 Running 0 27d
kube-system kube-flannel-ds-prnvf 1/1 Running 1 27d
kube-system kube-flannel-ds-xck8p 1/1 Running 0 27d
kube-system kube-proxy-2xrhl 1/1 Running 0 27d
kube-system kube-proxy-lnt9r 1/1 Running 0 27d
kube-system kube-proxy-m74ms 1/1 Running 0 27d
kube-system kube-proxy-vqdxt 1/1 Running 0 27d
kube-system kube-scheduler-kubctl-s-2vcpu-4gb-nyc3-01-master 1/1 Running 0 27d
kube-system kubernetes-dashboard-5bd6f767c7-7qp75 1/1 Running 0 26d
使用PING或Telnet时，需要连接到Kafka的POD可以到达群集:
# kubectl exec -it vizix-services-7bdccb48c4-2q8js bash
bash-4.2# ping 10.132.123.177
PING 10.132.123.177 (10.132.123.177) 56(84) bytes of data.
64 bytes from 10.132.123.177: icmp_seq=1 ttl=63 time=0.540 ms
64 bytes from 10.132.123.177: icmp_seq=2 ttl=63 time=0.518 ms
64 bytes from 10.132.123.177: icmp_seq=3 ttl=63 time=0.432 ms
64 bytes from 10.132.123.177: icmp_seq=4 ttl=63 time=0.527 ms
^C
--- 10.132.123.177 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3000ms
rtt min/avg/max/mdev = 0.432/0.504/0.540/0.045 ms
bash-4.2# telnet 10.132.123.177 9092
Trying 10.132.123.177...
Connected to 10.132.123.177.
Escape character is '^]'.
^CConnection closed by foreign host.
bash-4.2#
但是JAVA应用程序不能。仅使用docker，它可以正常连接，但是当Kubernetes启动pod时，它不能。
2018-05-30 01:25:06,993+0000 WARN [localhost-startStop-1] com.tierconnect.riot.commons.services.broker.KafkaPublisher:: -
Check if exists a connection to kafka server 10.132.123.177:9092 and services is able to publish to kafka.
Kubernetes是否有某些东西可以阻止某些特定的应用程序协议(protocol)从一个节点连接到外部主机？
这是该服务的部署YAML文件:
apiVersion: apps/v1
kind: Deployment
metadata:
name: microservice1
labels:
app: services
spec:
replicas: 1
selector:
matchLabels:
app: services
template:
metadata:
labels:
app: services
spec:
containers:
- name: microservice1
image: random/java-image:v6.5.2
env:
- name: KAFKA_SERVERS
value: "10.132.123.177:9092"
最佳答案
我使用端点和服务解决了这个问题。这种连接由Kubernetes管理:
---
kind: "Service"
apiVersion: "v1"
metadata:
name: "kafka"
spec:
ports:
-
name: "kafka"
protocol: "TCP"
port: 9092
targetPort: 9092
nodePort: 0
---
kind: "Endpoints"
apiVersion: "v1"
metadata:
name: "kafka"
subsets:
-
addresses:
-
ip: "10.128.0.2"
ports:
-
port: 9092
name: "kafka"
关于docker - Kubernetes节点无法访问外部Kafka集群，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/50595162/