環境:
1.在hadoop36機器，ping hadoop38機器的pod的ip，為172.30.1.4
2.該pod的service的external-ip的ip為hadoop36的ip
3.下面機器的ip，已經使用 xx.xx.xx.來替代和加圖層覆蓋掉

問題: 無法透過服務EXTERNAL-IP+port,訪問對應的pod的服務，說白了，就是無法訪問pod ip+port,無法ping通172.30.1.4

步驟:
1.先把服務停掉
[root@hadoop38 ~]# systemctl stop etcd flanneld docker kubelet kube-proxy

2.檢視當前規則，然後清空
[root@hadoop38 ~]# iptables -L -n

[root@hadoop38 ~]# iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat
[root@hadoop38 ~]# iptables -L -n
Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination
[root@hadoop38 ~]#

3.重啟iptables 和開啟服務
[root@hadoop38 ~]# systemctl restart iptables
[root@hadoop38 ~]# systemctl start etcd flanneld docker kubelet kube-proxy

4.再次檢視防火牆策略和清空掉
[root@hadoop38 ~]# iptables -L -n
[root@hadoop38 ~]# iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat

5.等待一會最終檢視防火牆策略
[root@hadoop38 ~]# iptables -L -n
Chain INPUT (policy ACCEPT)
target prot opt source destination
KUBE-FIREWALL all -- 0.0.0.0/0 0.0.0.0/0

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination
KUBE-FIREWALL all -- 0.0.0.0/0 0.0.0.0/0
KUBE-SERVICES all -- 0.0.0.0/0 0.0.0.0/0 /* kubernetes service portals */

Chain KUBE-FIREWALL (2 references)
target prot opt source destination
DROP all -- 0.0.0.0/0 0.0.0.0/0 /* kubernetes firewall for dropping marked packets */ mark match 0x8000/0x8000

Chain KUBE-SERVICES (1 references)
target prot opt source destination
[root@hadoop38 ~]# destination

6.在36機器驗證ping 和 telnet檢驗
[root@hadoop36 dns]# kubectl get all -n cdh -o wide
NAME READY STATUS RESTARTS AGE IP NODE
po/mysql-master-64k8r 1/1 Running 5 1h 172.30.1.4 xx.xx.xx.38

NAME DESIRED CURRENT READY AGE CONTAINER(S) IMAGE(S) SELECTOR
rc/mysql-master 1 1 1 1h master hadoop35.jiuye/k8sregister/jiuye/mysql5.6-master:v1.6 name=mysql-master

NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
svc/mysql-master 10.254.56.245 xx.xx.xx.36 13307/TCP 1h name=mysql-master
[root@hadoop36 dns]#

[root@hadoop36 dns]# ping 172.30.1.4
PING 172.30.1.4 (172.30.1.4) 56(84) bytes of data.
64 bytes from 172.30.1.4: icmp_seq=1 ttl=63 time=0.388 ms
^Z
[31]+ Stopped ping 172.30.1.4

[root@hadoop36 dns]# telnet   xx.xx.xx.36 13307
Trying xx.xx.xx..36...
Connected to xx.xx.xx..36.
Escape character is '^]'

備註:
1.這種情況發生過兩次(都是因為vm機器重啟)，特此記錄一下步驟，備查。

Kubernetes node的防火牆問題導致pod ip無法訪問

相關文章