Kubernetes集成Calico + 遇到的問題

1.背景

原來在使用kubernetes（v1.6.2）集羣網絡時，一直使用flannel，今天嘗試使用calico（v2.5.1）三層網絡路由模式進行部署安裝。

2.安裝

徹底參考官網手工搭建模式（Integration Guide）便可正常安裝，也能夠選擇官方推薦的hosted方式更加簡潔。官方指南：
https://docs.projectcalico.or...

3.Troubleshooting

（1）kubelet配置
第一個小插曲是kubelet的配置問題：

--cni-bin-dir=/opt/cni/bin

官網說若是是v1.4.0以上版本，cni-conf-dir和cni-bin-dir參數已經not supported了，須要使用--network-plugin-dir=/etc/cni/net.d參數配置。可是實際部署時，發現若是不配置cni-bin-dir程序會報錯：

Sep 25 12:28:42 datanode10 kubelet: E0925 12:28:42.979143  176648 remote_runtime.go:109] StopPodSandbox "d00d2e5c3579775ded32f9dc0099510b879c4facedafce462a7e07ce1700090f" from runtime service failed: rpc error: code = 2 desc = NetworkPlugin cni failed to teardown pod "kubernetes-dashboard-2445590520-xd1gv_kube-system" network: failed to find plugin "calico" in path [/etc/cni/net.d /opt/calico/bin]

kubernetes默認（多是待研究）會查找/opt/calico/bin路徑，配置好cni-bin-dir後再也不報錯啦。

（2）calico啓動參數
calicoctl啓動時的命令是：

calicoctl node run

比較有價值的參數是--node-image和--ip。第一次安裝時安裝官方文檔指定了--node-image=quay.io/calico/node:v2.5.1，沒有指定--ip，而後calico一直不能正常創建鏈接，使用calicoctl node diags查看日誌/tmp/calico230225863/diagnostics/logs/bird/current（須要自行解壓，在/tmp目錄下）：

2017-09-25_05:09:34.42961 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 37890)
2017-09-25_05:09:39.43958 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 51894)
2017-09-25_05:09:44.45164 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 33414)
2017-09-25_05:09:48.46058 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 57101)
2017-09-25_05:09:52.46944 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 46725)
2017-09-25_05:09:57.47937 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 55515)
2017-09-25_05:10:02.49236 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 40148)
2017-09-25_05:10:06.50045 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 44207)
2017-09-25_05:10:10.51034 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 56880)
2017-09-25_05:10:15.52110 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 33334)
2017-09-25_05:10:19.53213 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 41658)
2017-09-25_05:10:24.54219 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 38064)
2017-09-25_05:10:29.55189 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 60790)
2017-09-25_05:10:33.56258 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 50308)
2017-09-25_05:10:37.57183 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 38529)
2017-09-25_05:10:42.58203 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 52686)
2017-09-25_05:10:47.59242 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 38432)
2017-09-25_05:10:52.60446 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 36509)
2017-09-25_05:10:56.61362 bird: BGP: Unexpected connect from unknown address 10.1.8.103 (port 41643)

執行命令calicoctl node status後的狀態是connect和active *#$%，不是正常的established。後來仔細看了命令的內容，PEER ADDRESS被默認指定到另外一個ip上，果斷添加--ip參數，完美解決。

[root@datanode10 ~]# calicoctl node status
Calico process is running.

IPv4 BGP status
+--------------+-------------------+-------+----------+-------------+
| PEER ADDRESS |     PEER TYPE     | STATE |  SINCE   |    INFO     |
+--------------+-------------------+-------+----------+-------------+
| 10.1.8.103   | node-to-node mesh | up    | 10:26:38 | Established |
+--------------+-------------------+-------+----------+-------------+

（3）ping不通
一切部署順利完成，而後開始ping啦~ 可是發現一切都ping不通...不通... 那豈不是白安裝calico了... 而後慢慢地抓包發現連本機都ping不通（容器ping宿主機），可是能夠從veth pair抓到imcp的數據包。

接着查看ip forwarding也是正常配置，沒有問題。

再接下來以爲多是iptables的問題。果真... 在iptables中發現若干個DROP規則...必定是這裏...

:KUBE-MARK-DROP - [0:0]
-A KUBE-MARK-DROP -j MARK --set-xmark 0x8000/0x8000
-A DOCKER-ISOLATION -i docker0 -o br-dcd8c151afdd -j DROP
-A DOCKER-ISOLATION -i br-dcd8c151afdd -o docker0 -j DROP
-A KUBE-FIREWALL -m comment --comment "kubernetes firewall for dropping marked packets" -m mark --mark 0x8000/0x8000 -j DROP
-A cali-from-wl-dispatch -m comment --comment "cali:0CzWdDTPLgBBz6Ll" -m comment --comment "Unknown interface" -j DROP
-A cali-fw-cali2feb0dad56a -m comment --comment "cali:A3N5_YNzOIpK7HpM" -m conntrack --ctstate INVALID -j DROP
-A cali-fw-cali2feb0dad56a -m comment --comment "cali:80T7Du_D0q6hU5kt" -m comment --comment "Drop if no profiles matched" -j DROP
-A cali-pri-k8s_ns.default -m comment --comment "cali:yVw1jR_AsGFo9Rpe" -j DROP
-A cali-pro-k8s_ns.default -m comment --comment "cali:YnsVE8VOF5QMzGPk" -j DROP
-A cali-to-wl-dispatch -m comment --comment "cali:qpABzRADIk3YxZik" -m comment --comment "Unknown interface" -j DROP
-A cali-tw-cali2feb0dad56a -m comment --comment "cali:MGvDdzDcopAPnoXN" -m conntrack --ctstate INVALID -j DROP
-A cali-tw-cali2feb0dad56a -m comment --comment "cali:WCfHewdVqzxx80YL" -m comment --comment "Drop if no profiles matched" -j DROP

刪除calico的DROP規則後，跨主機的網絡就能夠正常通訊了。可是，到這裏尚未結束，正在思考爲何會有這些規則準備開放規則解決時，這些DROP又回來了，網絡又不通了...

不要緊繼續查看calico的配置，此處還發現calicoctl徹底模仿了kubectl的操做方式...更加方便啦~ 查看calico的各類狀態，發現profile內容是空的，可是規則裏有cali-pri-k8s_ns.default項（pri是profile inbound，pro是profile outbound），kubernetes和calico結合時沒有自動配置上（不理解）。

# calicoctl get profile
NAME

查看calico workloadEndpoint信息證明節點是屬於k8s_ns.default這個profile的。

- apiVersion: v1
  kind: workloadEndpoint
  metadata:
    activeInstanceID: e903eae04edbe9152d924c610121d62f02242c0791ec2e7d849975a2ea919922
    labels:
      calico/k8s_ns: default
    name: eth0
    node: datanode10
    orchestrator: k8s
    workload: default.nginx
  spec:
    interfaceName: calic440f455693
    ipNetworks:
    - 192.168.250.192/32
    mac: 22:4b:61:ee:e3:54
    profiles:
    - k8s_ns.default

沒有就本身動手添加一個...規則全放開...而後就通了...

apiVersion: v1
kind: profile
metadata:
  name: k8s_ns.default
  labels:
    calico/k8s_ns: default
spec:
  ingress:
  - action: allow
  egress:
  - action: allow

4.小結

以上是今天安裝部署時遇到的真實問題，暫時還不清楚是否是由於使用的不當致使的這些問題:(，後續會再學習calico的網絡原理，研究一段calico的配置使用。