K8S 之 Flannel之SNAT規(guī)劃優(yōu)化

一、Flannel之SNAT規(guī)劃優(yōu)化作用

解決兩宿主機(jī)容器之間的透明訪問，如不進(jìn)行優(yōu)化，容器之間的訪問，日志記錄為宿主機(jī)的IP地址。

1、宿主機(jī)訪問172.7.22.2的nginx容器情況

2、172.7.22.2查看nginx訪問日志

3、進(jìn)入172.7.21.2的容器訪問172.7.22.2的nginx容器，查看日志

4、再次查看172.7.22.2的nginx訪問日志

5、解決問題：當(dāng)容器172.7.21.2訪問172.7.22.2的nginx容器時(shí)，展示的日志應(yīng)為172.7.21.2

二、解決方法

1、安裝iptables-services組件
[root@test-nodes1 ~]# yum -y install iptables-services
[root@test-nodes1 ~]# systemctl start iptables
[root@test-nodes1 ~]# systemctl enable iptables
Created symlink from /etc/systemd/system/basic.target.wants/iptables.service to /usr/lib/systemd/system/iptables.service.
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2、把以下iptable記錄的偽裝轉(zhuǎn)向刪除
[root@test-nodes1 ~]# iptables-save |grep -i postrouting
:POSTROUTING ACCEPT [68:4098]
:KUBE-POSTROUTING - [0:0]
-A POSTROUTING -m comment --comment "kubernetes postrouting rules" -j KUBE-POSTROUTING
-A POSTROUTING -s 172.7.21.0/24 ! -o docker0 -j MASQUERADE       #刪除此條
-A KUBE-POSTROUTING -m comment --comment "kubernetes service traffic requiring SNAT" -m mark --mark 0x4000/0x4000 -j MASQUERADE
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3、刪除該記錄
[root@test-nodes1 ~]# iptables -t nat -D POSTROUTING -s 172.7.21.0/24 ! -o docker0 -j MASQUERADE
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4、插入一條新的記錄（排除對(duì)172.7.0.0/16網(wǎng)絡(luò)訪問的偽裝）
[root@test-nodes1 ~]# iptables -t nat -I POSTROUTING -s 172.7.21.0/24 ! -d 172.7.0.0/16 ! -o docker0 -j MASQUERADE
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5、查看是否生效
[root@test-nodes1 ~]# iptables-save |grep -i postrouting
:POSTROUTING ACCEPT [13:814]
:KUBE-POSTROUTING - [0:0]
-A POSTROUTING -s 172.7.21.0/24 ! -d 172.7.0.0/16 ! -o docker0 -j MASQUERADE
-A POSTROUTING -m comment --comment "kubernetes postrouting rules" -j KUBE-POSTROUTING
-A KUBE-POSTROUTING -m comment --comment "kubernetes service traffic requiring SNAT" -m mark --mark 0x4000/0x4000 -j MASQUERADE
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6、刪除iptables上所有reject拒絕規(guī)則
[root@test-nodes1 ~]# iptables-save | grep -i reject
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
[root@test-nodes1 ~]# iptables -t filter -D INPUT -j REJECT --reject-with icmp-host-prohibited
[root@test-nodes1 ~]# iptables -t filter -D FORWARD -j REJECT --reject-with icmp-host-prohibited
[root@test-nodes1 ~]# iptables-save | grep -i reject
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7、保存iptables規(guī)則
[root@test-nodes1 ~]# iptables-save > /etc/sysconfig/iptables

三、驗(yàn)證結(jié)果

1、通過容器172.7.21.2訪問172.7.22.2

2、查看172.7.22.2的容器日志

備注：test-nodes需要有相同的操作