kubernetes:从pods访问外部系统不起作用

t98cgbkg  于 2021-06-08  发布在  Kafka
关注(0)|答案(1)|浏览(352)

我试图在kubernetes pod内(minikube vm内)访问外部zookeeper/kafka(kubernetes域外),这基本上不起作用。
首先,我有一个docker映像,它运行一个spring引导应用程序,并在启动时尝试连接端口2181/9092上的kafka示例。因为我创建了一个带有端点的服务,该端点指向应该修复路由的外部主机/ip,但不幸的是它没有。
以下是服务/端点的定义

apiVersion: v1
kind: Service
metadata:
  name: ext-kafka
  namespace: default
spec:
  clusterIP: None
  ports:
  - port: 2181
    name: zk
    protocol: TCP
    targetPort: 2181
  - port: 9092
    name: kafka
    protocol: TCP
    targetPort: 9092
---
apiVersion: v1
kind: Endpoints
metadata:
  name: ext-kafka
  namespace: default
subsets:
- addresses:
  # 192.168.99.1 is the external IP
  - ip: 192.168.99.1
  ports:
  - port: 2181
    name: zk
  - port: 9092
    name: kafka

# 

# HERE ARE THE DEPLOYMENTS/DEFINITIONS THAT THE SERVICES ARE INSTALLED

# 

[root@centos1 work]# kubectl get services
NAME                      CLUSTER-IP   EXTERNAL-IP   PORT(S)             AGE
ext-kafka                 None         <none>        2181/TCP,9092/TCP   2d

 ...

[root@centos1 work]# kubectl get endpoints
NAME                      ENDPOINTS                             AGE
ext-kafka                 192.168.99.1:2181,192.168.99.1:9092   2d

我检查了minikube vm上的iptables,因为它指出包被拒绝了。所以清理并不能解决问题,因为它会在幕后自动重新创建。

$ iptables -L
....

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination         
KUBE-FIREWALL  all  --  anywhere             anywhere            
KUBE-SERVICES  all  --  anywhere             anywhere             /* kubernetes service portals */

...

Chain KUBE-FIREWALL (2 references)
target     prot opt source               destination         
DROP       all  --  anywhere             anywhere             /* kubernetes firewall for dropping marked packets */ mark match 0x8000/0x8000

Chain KUBE-SERVICES (1 references)
target     prot opt source               destination         
....
REJECT     tcp  --  anywhere             anywhere             /* default/server-command: has no endpoints */ ADDRTYPE match dst-type LOCAL tcp dpt:30021 reject-with icmp-port-unreachable
REJECT     tcp  --  anywhere             10.0.0.240           /* default/server-command: has no endpoints */ tcp dpt:webcache 

....

另一种缓解星座问题的方法是:
我和你一起跑ncat ncat -l 192.168.99.1 2181 --keep-open 在主机上,zookeeper/kafka应该在其中运行并尝试从minikube vm与 telnet 192.168.99.1 2181 我有'没有轮班主持'。。。
那么如何解决这个问题呢??如何添加服务,解决iptables问题我使用了builddate的kubernetes构建:“2017-05-10t15:48:59z”)
比尔

os8fio9y

os8fio9y1#

当您使用minikube时,我认为问题是因为zookeeper/kafka的ip地址(192.168.99.1)。您可以看到minikube正在网络192.168.99.0/24上工作 minikube ssh 执行 ip addr ```
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 08:00:27:97:6c:ed brd ff:ff:ff:ff:ff:ff
inet 192.168.99.100/24 brd 192.168.99.255 scope global dynamic eth1
valid_lft 798sec preferred_lft 798sec
inet6 fe80::a00:27ff:fe97:6ced/64 scope link
valid_lft forever preferred_lft forever

因此,如果zookeeper/kafka应该在minikube网络之外,则可能与ip冲突。我建议您对此外部服务使用不同的ip(例如:192.168.200.xx)。

相关问题