本文记录KubeEdge实践的一些记录，包括疑问和解决方案。本文不定时更新。
杂项
编译kubeedge，内存为2GB会出错，4G正常。
同一个pod导出节点端口相同，扩容会不成功，因为节点端口已被占用。
需要先运行得到配置文件，再修改。注意配置文件位置，注意系统平台框架，如果是arm平台，但pause不使用kubeedge/pause-arm:3.1，则出错。
检查主机名称，必须合规（小写字母、数字、横杠-、点号.），否则注册不了，有时返回信息为err:<nil>，无法排查。
边缘端系统需要有默认网关，否则运行会有段错误。按issue说法，此已解决，但依然有。
KubeEdge 不完全等同于 k8s，k8s的部分命令还没有实现。如查看、运行容器的命令就没有。
我收集的相关的bug
2020.3.19记录：
不支持kubectl exec和kubectl logs命令，官方说后续支持。待观察。
调度信息不够。从kubectl describe中只知道成功调度到了某个节点，至于成功或失败，不知道。只能到节点机器看用docker logs查日志。
问题
无法调度
环境：3台主机，已部署k8s。清理k8s。
按k8s部署deployment，查看pod，显示Pending，删除pod，显示Terminating。再尝试，发现有一个pod可运行在其中一节点，扩容，该节点可运行，另一节点Pending。经过一晚，依旧。
强制停止cloudcore 和 edgecore，k8s中的节点显示NotReady。节点的容器依旧在运行。
疑问：
无法调度，何解？如果优雅关掉pod，再停止cloudcore？目前找不到方法。
云端打印：
messagehandler.go:448] write error, connection for node edge-node2 will be closed, affected event id: dba8d7ec-ffa4-4c6f-ac6e-accfa527a366, parent_id: , group: resource, source: edgecontroller, resource: default/pod/nginx-deployment-77698bff7d-jdm8k, operation: update, reason tls: use of closed connection
边缘端打印：
process.go:130] failed to send message: tls: use of closed connection
process.go:196] websocket write error: failed to send message, error: tls: use of closed connection
猜测：连接断开，但查看node状态，是Ready状态，不知何故。
后续：删除，过一段时间，再部署，成功。
正常连接，跑，一夜后，NotReady状态。pod不断销毁，不断创建。
# kubectl get pod
NAME READY STATUS RESTARTS AGE
led-light-mapper-deployment-94bbdf88-26h2d 0/1 Terminating 0 14h
led-light-mapper-deployment-94bbdf88-2hwxq 0/1 Terminating 0 90m
led-light-mapper-deployment-94bbdf88-4f8pd 0/1 Terminating 0 80m
led-light-mapper-deployment-94bbdf88-52p9w 0/1 Terminating 0 15m
led-light-mapper-deployment-94bbdf88-8t9cl 0/1 Terminating 0 30m
led-light-mapper-deployment-94bbdf88-9bpt7 0/1 Terminating 0 95m
led-light-mapper-deployment-94bbdf88-9nfk6 0/1 Terminating 0 65m
led-light-mapper-deployment-94bbdf88-c8wtb 0/1 Terminating 0 85m
led-light-mapper-deployment-94bbdf88-kpcx4 0/1 Terminating 0 75m
led-light-mapper-deployment-94bbdf88-kwgqs 0/1 Terminating 0 35m
led-light-mapper-deployment-94bbdf88-l6hn2 0/1 Terminating 0 55m
led-light-mapper-deployment-94bbdf88-pk6fx 0/1 Terminating 0 5m1s
led-light-mapper-deployment-94bbdf88-qk9gj 0/1 Terminating 0 60m
led-light-mapper-deployment-94bbdf88-sgns2 0/1 Terminating 0 100m
led-light-mapper-deployment-94bbdf88-sk8gf 0/1 Terminating 0 20m
led-light-mapper-deployment-94bbdf88-svkgr 0/1 Terminating 0 50m
led-light-mapper-deployment-94bbdf88-tjz7z 0/1 Terminating 0 45m
led-light-mapper-deployment-94bbdf88-vwx7w 0/1 Pending 0 1s
led-light-mapper-deployment-94bbdf88-xfsc8 0/1 Terminating 0 10m
led-light-mapper-deployment-94bbdf88-xpq8k 0/1 Terminating 0 40m
led-light-mapper-deployment-94bbdf88-zhj24 0/1 Terminating 0 25m
led-light-mapper-deployment-94bbdf88-zncjg 0/1 Terminating 0 70m
查边缘端：
I0319 09:17:05.425874 2147 communicate.go:151] has msg
I0319 09:17:05.426062 2147 communicate.go:155] redo task due to no recv
I0319 09:17:05.427233 2147 communicate.go:151] has msg
I0319 09:17:05.427416 2147 communicate.go:155] redo task due to no recv
I0319 09:17:05.428657 2147 dtcontext.go:69] CommModule is healthy 1584580625
context_channel.go:175] the message channel is full, message: {Header:{ID:5f072fe2-b8cf-411e-8aee-16e927f27433 ParentID: Timestamp:1584580605260 ResourceVersion:391570 Sync:false} Router:{Source:edgecontroller Group:resource Operation:update Resource:default/pod/led-light-mapper-deployment-94bbdf88-26h2d} Content:map[metadata:map[creationTimestamp:2020-03-18T10:23:50Z deletionGracePeriodSeconds:30 deletionTimestamp:2020-03-18T23:40:09Z generateName:led-light-mapper-deployment-94bbdf88- labels:map[app:led-light-mapper pod-template-hash:94bbdf88] name:led-light-mapper-deployment-94bbdf88-26h2d namespace:default ownerReferences:[map[apiVersion:apps/v1 blockOwnerDeletion:true controller:true kind:ReplicaSet name:led-light-mapper-deployment-94bbdf88 uid:52c44b48-1214-4b10-9007-23093a953a40]] resourceVersion:391570 selfLink:/api/v1/namespaces/default/pods/led-light-mapper-deployment-94bbdf88-26h2d uid:12002c7e-69fe-4a31-bf66-759d78380abe] spec:map[containers:[map[image:latelee/led-light-mapper:v1.1 imagePullPolicy:IfNotPresent name:led-light-mapper-container resources:map[] securityContext:map[privileged:true] terminationMessagePath:/dev/termination-log terminationMessagePolicy:File volumeMounts:[map[mountPath:/opt/kubeedge/ name:config-volume] map[mountPath:/var/run/secrets/kubernetes.io/serviceaccount name:default-token-gb4kq readOnly:true]]]] dnsPolicy:ClusterFirst enableServiceLinks:true hostNetwork:true nodeName:latelee.org.ttucon-2142ec priority:0 restartPolicy:Always schedulerName:default-scheduler securityContext:map[] serviceAccount:default serviceAccountName:default terminationGracePeriodSeconds:30 tolerations:[map[effect:NoExecute key:node.kubernetes.io/not-ready operator:Exists tolerationSeconds:300] map[effect:NoExecute key:node.kubernetes.io/unreachable operator:Exists tolerationSeconds:300]] volumes:[map[configMap:map[defaultMode:420 name:device-profile-config-edge-node2] name:config-volume] map[name:default-token-gb4kq secret:map[defaultMode:420 secretName:default-token-gb4kq]]]] status:map[phase:Pending qosClass:BestEffort]]}
DNS警告：
I0319 16:25:18.563472 17947 record.go:24] Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to "Default" policy.
I0319 16:25:18.563724 17947 record.go:24] Warning MissingClusterDNS pod: "webgin-deployment-747c6887f5-dwmtb_default(1ceb1dd6-6dae-4aff-a2c6-d0de64373031)". kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to "Default" policy.
I0319 16:25:18.563902 17947 record.go:19] Warning DNSConfigForming Nameserver limits were exceeded, some nameservers have been omitted, the applied nameserver line is: 8.8.8.8 8.8.4.4 2001:4860:4860::8888
E0319 16:25:18.564035 17947 dns.go:135] Nameserver limits were exceeded, some nameservers have been omitted, the applied nameserver line is: 8.8.8.8 8.8.4.4 2001:4860:4860::8888
I0319 16:30:09.037479 17947 edged.go:808] consume added pod [webgin-deployment-7ccff86d8b-s227c] successfully
I0319 16:30:10.506631 17947 record.go:19] Normal Started Started container webgin
E0319 16:30:10.507199 17947 kuberuntime_container.go:172] Failed to create legacy symbolic link "/var/log/containers/webgin-deployment-747c6887f5-f6547_default_webgin-1772b70cd7725f77c30b9cf47e3ce57159d9fdccf47c0c19aed8edf779c52c16.log" to container "1772b70cd7725f77c30b9cf47e3ce57159d9fdccf47c0c19aed8edf779c52c16" log "/var/log/pods/default_webgin-deployment-747c6887f5-f6547_abc27c3c-50f1-49e9-9f2e-b00fa802dc7f/webgin/0.log": symlink /var/log/pods/default_webgin-deployment-747c6887f5-f6547_abc27c3c-50f1-49e9-9f2e-b00fa802dc7f/webgin/0.log /var/log/containers/webgin-deployment-747c6887f5-f6547_default_webgin-1772b70cd7725f77c30b9cf47e3ce57159d9fdccf47c0c19aed8edf779c52c16.log: no such file or directory
I0319 16:30:10.507557 17947 edged.go:808] consume added pod [webgin-deployment-747c6887f5-f6547] successfully
I0319 16:30:10.667156 17947 edged.go:648] sync loop ignore event: [ContainerDied], with pod [1ceb1dd6-6dae-4aff-a2c6-d0de64373031] not found
W0319 16:30:10.685178 17947 docker_sandbox.go:394] failed to read pod IP from plugin/docker: Couldn't find network status for default/webgin-deployment-747c6887f5-f6547 through plugin: invalid network status for
W0319 16:30:10.871129 17947 docker_sandbox.go:394] failed to read pod IP from plugin/docker: Couldn't find network status for default/webgin-deployment-747c6887f5-f6547 through plugin: invalid network status for
I0319 16:30:10.914857 17947 container_manager_linux.go:880] Found 44 PIDs in root, 44 of them are not to be moved
I0319 16:30:11.088286 17947 edged.go:645] sync loop get event [ContainerStarted], ignore it now.
I0319 16:30:11.327738 17947 edged.go:645] sync loop get event [ContainerStarted], ignore it now.
W0319 16:30:12.413498 17947 docker_sandbox.go:394] failed to read pod IP from plugin/docker: Couldn't find network status for default/webgin-deployment-747c6887f5-f6547 through plugin: invalid network status for
W0319 16:30:12.543879 17947 docker_sandbox.go:394] failed to read pod IP from plugin/docker: Couldn't find network status for default/webgin-deployment-747c6887f5-f6547 through plugin: invalid network status for
成功部署pod的：
I0319 16:25:18.564503 17947 edged.go:808] consume added pod [webgin-deployment-747c6887f5-dwmtb] successfully
I0319 16:25:18.564974 17947 proxy.go:318] [L4 Proxy] process other resource: kube-system/endpoints/kube-scheduler
I0319 16:25:18.688263 17947 edged_volumes.go:54] Using volume plugin "kubernetes.io/empty-dir" to mount wrapped_default-token-gb4kq