1. kubernetes的ReplicationController文件配置

apiVersion: v1
kind: ReplicationController ##表明这个是kubernetes的RC资源，这个是比较低级和基础的资源
metadata: 
  name: kubetest  ##这个是RC资源的名字，全局唯一，可以通过kubectl get rc查看
spec: 
  replicas: 1  ##副本的数量
  selector: 
    app: kubetest  ##RC资源，选择label的标签
  template: 
    metadata: 
      labels:
        app: kubetest ##定义pod的资源label，很重要的一个属性，是被其他service、rc等资源选择标志
    spec:
      containers: ## 容器的属性
        -  name: kubetest
           image: 192.168.1.130:5000/kubetest:9  ##docker的images
           ports: 
             -  containerPort: 8080

2.启动

启动：kubectl create -f kubetest-rc.yaml
查看ReplicationController 的情况：kubectl get rc，显示如下

NAME       DESIRED   CURRENT   READY     AGE
kubetest   1         1         1         33m

查看pod的情况：kubectl get pod

NAME             READY     STATUS    RESTARTS   AGE
kubetest-8s1rt   1/1       Running   0          35m

查看node的情况：kubectl get node

NAME        STATUS    AGE
127.0.0.1   Ready     24d

查看node的详细信息：kubectl describe node 127.0.0.1

[root@localhost registry.access.redhat.com]# kubectl describe node 127.0.0.1
Name:                   127.0.0.1
Role:
Labels:                 beta.kubernetes.io/arch=amd64
                        beta.kubernetes.io/os=linux
                        kubernetes.io/hostname=127.0.0.1
Taints:                 <none>
CreationTimestamp:      Tue, 27 Mar 2018 05:30:36 +0800
Phase:
Conditions:
  Type                  Status  LastHeartbeatTime                       LastTransitionTime                      Reason                          Message
  ----                  ------  -----------------                       ------------------                      ------                          -------
  OutOfDisk             False   Fri, 20 Apr 2018 05:53:28 +0800         Fri, 20 Apr 2018 05:22:45 +0800         KubeletHasSufficientDisk        kubelet has sufficient disk space available
  MemoryPressure        False   Fri, 20 Apr 2018 05:53:28 +0800         Tue, 27 Mar 2018 05:30:36 +0800         KubeletHasSufficientMemory      kubelet has sufficient memory available
  DiskPressure          False   Fri, 20 Apr 2018 05:53:28 +0800         Tue, 27 Mar 2018 05:30:36 +0800         KubeletHasNoDiskPressure        kubelet has no disk pressure
  Ready                 True    Fri, 20 Apr 2018 05:53:28 +0800         Fri, 20 Apr 2018 05:26:26 +0800         KubeletReady                    kubelet is posting ready status
Addresses:              127.0.0.1,127.0.0.1,127.0.0.1
Capacity:
 alpha.kubernetes.io/nvidia-gpu:        0
 cpu:                                   2
 memory:                                2862816Ki
 pods:                                  110
Allocatable:
 alpha.kubernetes.io/nvidia-gpu:        0
 cpu:                                   2
 memory:                                2862816Ki
 pods:                                  110
System Info:
 Machine ID:                    46fe0c0dfdd3404e957c22297da1d059
 System UUID:                   F03A4D56-380A-3AA7-8FE7-0BE2EF78035A
 Boot ID:                       2f34ef81-e0fb-493b-b514-30f83e2b7a06
 Kernel Version:                3.10.0-693.21.1.el7.x86_64
 OS Image:                      CentOS Linux 7 (Core)
 Operating System:              linux
 Architecture:                  amd64
 Container Runtime Version:     docker://1.13.1
 Kubelet Version:               v1.5.2
 Kube-Proxy Version:            v1.5.2
ExternalID:                     127.0.0.1
Non-terminated Pods:            (1 in total)
  Namespace                     Name                    CPU Requests    CPU Limits      Memory Requests Memory Limits
  ---------                     ----                    ------------    ----------      --------------- -------------
  default                       kubetest-8s1rt          0 (0%)          0 (0%)          0 (0%)          0 (0%)
Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.
  CPU Requests  CPU Limits      Memory Requests Memory Limits
  ------------  ----------      --------------- -------------
  0 (0%)        0 (0%)          0 (0%)          0 (0%)
Events:
  FirstSeen     LastSeen        Count   From                    SubObjectPath   Type            Reason                  Message
  ---------     --------        -----   ----                    -------------   --------        ------                  -------
  30m           30m             1       {kubelet 127.0.0.1}                     Normal          Starting                Starting kubelet.
  30m           30m             1       {kubelet 127.0.0.1}                     Warning         ImageGCFailed           unable to find data for container /
  30m           30m             2       {kubelet 127.0.0.1}                     Normal          NodeHasSufficientDisk   Node 127.0.0.1 status is now: NodeHasSufficientDisk
  30m           30m             1       {kubelet 127.0.0.1}                     Normal          NodeHasSufficientMemory Node 127.0.0.1 status is now: NodeHasSufficientMemory
  30m           30m             1       {kubelet 127.0.0.1}                     Normal          NodeHasNoDiskPressure   Node 127.0.0.1 status is now: NodeHasNoDiskPressure
  30m           30m             1       {kubelet 127.0.0.1}                     Normal          NodeNotReady            Node 127.0.0.1 status is now: NodeNotReady
  30m           30m             1       {kubelet 127.0.0.1}                     Normal          NodeReady               Node 127.0.0.1 status is now: NodeReady
  27m           27m             1       {kubelet 127.0.0.1}                     Warning         ImageGCFailed           unable to find data for container /
  27m           27m             1       {kubelet 127.0.0.1}                     Normal          Starting                Starting kubelet.
  27m           27m             1       {kubelet 127.0.0.1}                     Normal          NodeHasSufficientDisk   Node 127.0.0.1 status is now: NodeHasSufficientDisk
  27m           27m             1       {kubelet 127.0.0.1}                     Normal          NodeHasSufficientMemory Node 127.0.0.1 status is now: NodeHasSufficientMemory
  27m           27m             1       {kubelet 127.0.0.1}                     Normal          NodeHasNoDiskPressure   Node 127.0.0.1 status is now: NodeHasNoDiskPressure
  27m           27m             1       {kubelet 127.0.0.1}                     Warning         Rebooted                Node 127.0.0.1 has been rebooted, boot id: 2f34ef81-e0fb-493b-b514-30f83e2b7a06
  27m           27m             1       {kubelet 127.0.0.1}                     Normal          NodeNotReady            Node 127.0.0.1 status is now: NodeNotReady
  27m           27m             1       {kubelet 127.0.0.1}                     Normal          NodeReady               Node 127.0.0.1 status is now: NodeReady
  10m           10m             2       {kubelet 127.0.0.1}                     Warning         MissingClusterDNS       kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. pod: "kubetest-8s1rt_default(ccc51f1f-4416-11e8-a44c-000c2978035a)". Falling back to DNSDefault policy.

查看pod的详情，其中包括Event事件，是很重要的信息kubectl describe pod kubetest-8s1rt

[root@localhost registry.access.redhat.com]# kubectl describe pod kubetest-8s1rt
Name:           kubetest-8s1rt
Namespace:      default
Node:           127.0.0.1/127.0.0.1
Start Time:     Fri, 20 Apr 2018 05:26:21 +0800
Labels:         app=kubetest
Status:         Running
IP:             172.17.0.2
Controllers:    ReplicationController/kubetest
Containers:
  kubetest:
    Container ID:               docker://6b1409d4214bce7d55b9d0582cfffd1f625d5690d1549a5ca20a3121a1a7d736
    Image:                      192.168.1.130:5000/kubetest:9
    Image ID:                   docker-pullable://192.168.1.130:5000/kubetest@sha256:8e5773b23d775c414d25ee231e11403367b682ca713da6174cfd4e529343dda3
    Port:                       8080/TCP
    State:                      Running
      Started:                  Fri, 20 Apr 2018 05:42:42 +0800
    Ready:                      True
    Restart Count:              0
    Volume Mounts:              <none>
    Environment Variables:      <none>
Conditions:
  Type          Status
  Initialized   True 
  Ready         True 
  PodScheduled  True 
No volumes.
QoS Class:      BestEffort
Tolerations:    <none>
Events:
  FirstSeen     LastSeen        Count   From                    SubObjectPath   Type            Reason                  Message
  ---------     --------        -----   ----                    -------------   --------        ------                  -------
  41m           33m             29      {default-scheduler }                    Warning         FailedScheduling        no nodes available to schedule pods
  30m           30m             1       {default-scheduler }                    Normal          Scheduled               Successfully assigned kubetest-8s1rt to 127.0.0.1
  30m           19m             7       {kubelet 127.0.0.1}                     Warning         FailedSync              Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure:latest, this may be because there are no credentials on this request.  details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)"

  29m   14m     65      {kubelet 127.0.0.1}             Warning FailedSync      Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""

  13m   13m     2       {kubelet 127.0.0.1}                                     Warning MissingClusterDNS       kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
  13m   13m     1       {kubelet 127.0.0.1}     spec.containers{kubetest}       Normal  Pulled                  Container image "192.168.1.130:5000/kubetest:9" already present on machine
  13m   13m     1       {kubelet 127.0.0.1}     spec.containers{kubetest}       Normal  Created                 Created container with docker id 6b1409d4214b; Security:[seccomp=unconfined]
  13m   13m     1       {kubelet 127.0.0.1}     spec.containers{kubetest}       Normal  Started                 Started container with docker id 6b1409d4214b