kubernetes若干问题

kubernetes若干问题

在将fabric compose启动方法转为k8s启动方法中，遇到的各种问题.

• Q1: kubernetes exec 访问不到pod

  root@liu:~/dns# kubectl exec -it busybox date
  Error from server: error dialing backend: dial tcp 172.16.199.55:10250: connect: connection refused

• A:修改本机host或者修改kubelet启动参数

    该问题主要与配置的启动参数有关，搭建的是一个solo集群，master和node在一个宿          主机器上，并且配置的kubelet地址参数为127.0.0.1,而本机器的host记录的是本地的  
  私有地址172.16.199.55,这就造成了访问不通的问题.
  

  • 方法1:修改本机host

    root@liu:~# hostname
    liu
    root@liu:~# cat /etc/hosts
    127.0.0.1   localhost
    
     # The following lines are desirable for IPv6 capable hosts
    ::1 localhost   ip6-localhost   ip6-loopback
    ff02::1 ip6-allnodes
    ff02::2 ip6-allrouters
    172.16.199.55   liu 
    
     #修改172.16.199.55   liu 为 127.0.0.1 liu
     #或者 在 127.0.0.1 localhost 后加上hostname
     #127.0.0.1 localhost  liu
    root@liu:~# ping liu
    PING localhost (127.0.0.1) 56(84) bytes of data.
    64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.035 ms
    ^C
     #访问容器
    root@liu:~/dns# kubectl exec -it busybox date
    Thu Aug 30 07:15:50 UTC 2018

  • 方法2: 修改kubelet启动参数

    root@liu:~# cat /etc/kubernetes/kubelet
    
     ## The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
    KUBELET_ADDRESS="--address=127.0.0.1"
     #修改KUBELET_ADDRESS="--address=127.0.0.1"为
     #KUBELET_ADDRESS="--address=172.16.199.55" 
     #重新启动kubelet服务
    root@liu:~# systemctl restart kubelet.service 
     #访问容器
    root@liu:~/dns# kubectl exec -it busybox date
    Thu Aug 30 07:15:50 UTC 2018
    

  • 参考：Error from server: error dialing backend: dial tcp: lookup xxx on 114.114.114.114:53: no such

  • 解决过程:

      开始以为是没有配置DNS的问题，但是后来想，第一个实例（guestbook)已经跑通，所  
    以,内部DNS是正确的，外部访问可以kubectl get node/pod都正确，甚至配置了CNI,  
    问题依旧.
      之前也查到说修改host，但是，我这是solo集群，为什么还需要配置host？于是认为  
    可能是添加pod，仍然不对.偶然间看到别人多主机集群也有这个问题，并通过添加节点  
    host解决该问题.
      于是，hostname查看我的主机名为liu,ping了一下主机名，显示172.16.199.55,  
    再想到我配置的地址参数一般是127.0.0.1，随即/etc/hosts添加127.0.0.1 liu，  
    访问容器反馈了正确结果.
      最后查到是kubelet启动参数:--address=127.0.0.1的问题.
    

• Q2: v1.EnvVar.Value: ReadString: expects ” or n, but found t, error found in #10 byte of …|,”value”:true}]

  root@liu:~/work/e2e_cli_k8s/fabric_orderer# kubectl create -f orderer-deployment.yaml 
  Error from server (BadRequest): error when creating "orderer-deployment.yaml": Deployment in version "v1beta1" cannot be handled as a Deployment: v1beta1.Deployment.Spec: v1beta1.DeploymentSpec.Template: v1.PodTemplateSpec.Spec: v1.PodSpec.Containers: []v1.Container: v1.Container.Env: []v1.EnvVar: v1.EnvVar.Value: ReadString: expects " or n, but found t, error found in #10 byte of ...|,"value":true}],"ima|..., bigger context ...|":"30s"},{"name":"ORDERER_KAFKA_VERBOSE","value":true}],"image":"hyperledger/fabric-orderer","imageP|...   
  
  root@liu:~/work/e2e_cli_k8s/fabric_orderer# cat orderer-deployment.yaml 
  ---
  
  kind: Deployment
  apiVersion: extensions/v1beta1
  - name: ORDERER_KAFKA_VERBOSE
   #...   
   env: 
   #...       
   - name: ORDERER_GENERAL_TLS_PRIVATEKEY
     value: '/var/hyperledger/orderer/tls/server.key'
   - name: ORDERER_GENERAL_TLS_CERTIFICATE
     value: '/var/hyperledger/orderer/tls/server.crt'
   - name: ORDERER_GENERAL_TLS_ROOTCAS
     value: '[/var/hyperledger/orderer/tls/ca.crt]'
   - name: ORDERER_KAFKA_RETRY_SHORTINTERVAL
     value: 1s
   - name: ORDERER_KAFKA_RETRY_SHORTTOTAL
     value: 30s
   - name: ORDERER_KAFKA_VERBOSE
     value: true 
  

• A:kubernetes的env label value只支持string
  
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