我的 kubernetes pod 不断因“CrashLoopBackOff"而崩溃；但我找不到任何日志 [英] My kubernetes pods keep crashing with "CrashLoopBackOff" but I can't find any log

问题描述

这就是我不断得到的:

[root@centos-master ~]# kubectl get pods
NAME               READY     STATUS             RESTARTS   AGE
nfs-server-h6nw8   1/1       Running            0          1h
nfs-web-07rxz      0/1       CrashLoopBackOff   8          16m
nfs-web-fdr9h      0/1       CrashLoopBackOff   8          16m

下面是describe pods的输出kubectl 描述 pods

Events:
  FirstSeen LastSeen    Count   From                SubobjectPath       Type        Reason      Message
  --------- --------    -----   ----                -------------       --------    ------      -------
  16m       16m     1   {default-scheduler }                    Normal      Scheduled   Successfully assigned nfs-web-fdr9h to centos-minion-2
  16m       16m     1   {kubelet centos-minion-2}   spec.containers{web}    Normal      Created     Created container with docker id 495fcbb06836
  16m       16m     1   {kubelet centos-minion-2}   spec.containers{web}    Normal      Started     Started container with docker id 495fcbb06836
  16m       16m     1   {kubelet centos-minion-2}   spec.containers{web}    Normal      Started     Started container with docker id d56f34ae4e8f
  16m       16m     1   {kubelet centos-minion-2}   spec.containers{web}    Normal      Created     Created container with docker id d56f34ae4e8f
  16m       16m     2   {kubelet centos-minion-2}               Warning     FailedSync  Error syncing pod, skipping: failed to "StartContainer" for "web" with CrashLoopBackOff: "Back-off 10s restarting failed container=web pod=nfs-web-fdr9h_default(461c937d-d870-11e6-98de-005056040cc2)"

我有两个 Pod:nfs-web-07rxz、nfs-web-fdr9h，但是如果我这样做 kubectl logs nfs-web-07rxz 或使用 -p 选项，我在两个 Pod 中都看不到任何日志.

I have two pods: nfs-web-07rxz, nfs-web-fdr9h, but if I do kubectl logs nfs-web-07rxz or with -p option I don't see any log in both pods.

[root@centos-master ~]# kubectl logs nfs-web-07rxz -p
[root@centos-master ~]# kubectl logs nfs-web-07rxz

这是我的 replicationController yaml 文件:replicationController yaml 文件

This is my replicationController yaml file: replicationController yaml file

apiVersion: v1 kind: ReplicationController metadata:   name: nfs-web spec:   replicas: 2   selector:
    role: web-frontend   template:
    metadata:
      labels:
        role: web-frontend
    spec:
      containers:
      - name: web
        image: eso-cmbu-docker.artifactory.eng.vmware.com/demo-container:demo-version3.0
        ports:
          - name: web
            containerPort: 80
        securityContext:
          privileged: true

我的 Docker 镜像是由这个简单的 docker 文件制作的:

My Docker image was made from this simple docker file:

FROM ubuntu
RUN apt-get update
RUN apt-get install -y nginx
RUN apt-get install -y nfs-common

我在 CentOs-1611 上运行我的 kubernetes 集群，kube 版本:

I am running my kubernetes cluster on CentOs-1611, kube version:

[root@centos-master ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"3", GitVersion:"v1.3.0", GitCommit:"86dc49aa137175378ac7fba7751c3d3e7f18e5fc", GitTreeState:"clean", BuildDate:"2016-12-15T16:57:18Z", GoVersion:"go1.6.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"3", GitVersion:"v1.3.0", GitCommit:"86dc49aa137175378ac7fba7751c3d3e7f18e5fc", GitTreeState:"clean", BuildDate:"2016-12-15T16:57:18Z", GoVersion:"go1.6.3", Compiler:"gc", Platform:"linux/amd64"}

如果我通过 docker run 运行 docker 镜像，我可以毫无问题地运行镜像，只有通过 kubernetes 我才崩溃.

If I run the docker image by docker run I was able to run the image without any issue, only through kubernetes I got the crash.

谁能帮帮我，我如何在不看到任何日志的情况下进行调试?

Can someone help me out, how can I debug without seeing any log?

推荐答案

正如@Sukumar 所评论的，你需要让你的 Dockerfile 有一个 Command 运行或让您的 ReplicationController 指定命令.

As @Sukumar commented, you need to have your Dockerfile have a Command to run or have your ReplicationController specify a command.

Pod 崩溃是因为它启动然后立即退出，因此 Kubernetes 重新启动并继续循环.

The pod is crashing because it starts up then immediately exits, thus Kubernetes restarts and the cycle continues.

这篇关于我的 kubernetes pod 不断因“CrashLoopBackOff"而崩溃；但我找不到任何日志的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！