我正在尝试使用以下文件设置 kubernetes pod。 该镜像只是来自 Docker HUB 的基本 hello-world 镜像。
但我不断收到错误消息。
通过以下命令创建部署
kubectl apply -f config.yaml
没有错误并说部署已创建。 但是几秒钟后，当我尝试通过以下命令查看 pod 时，出现这些错误。
kubectl get pod
输出
some-deployment-857fb6d98b-jzwhq 0/1 ImagePullBackOff 0
some-deployment-857fb6d98b-ethfs 0/1 ImagePullBackOff 0
some-deployment-857fb6d98b-w8hgt 0/1 ImagePullBackOff 0
一段时间后，当我运行相同的 get pod 命令时，我得到了这些。
some-deployment-6f88c9fd89-65c47 0/1 CrashLoopBackOff 8
some-deployment-84d66585d4-k52ns 0/1 CrashLoopBackOff 9
some-deployment-857fb6d98b-jzwhq 0/1 ErrImagePull 0
some-deployment-857fb6d98b-w8hgt 0/1 ErrImagePull 0
我刚刚换了一张图片，看看是不是图片有问题。
它一直在变化。为什么我现在有 4 个 Pod？
some-deployment-6f88c9fd89-65c47 0/1 Completed 8
some-deployment-84d66585d4-k52ns 0/1 CrashLoopBackOff 8
some-deployment-857fb6d98b-jzwhq 0/1 ImagePullBackOff 0
some-deployment-857fb6d98b-w8hgt 0/1 ImagePullBackOff 0
过了一会儿。
some-deployment-6f88c9fd89-65c47 0/1 CrashLoopBackOff 8
some-deployment-84d66585d4-k52ns 0/1 CrashLoopBackOff 9
some-deployment-857fb6d98b-jzwhq 0/1 ImagePullBackOff 0
some-deployment-857fb6d98b-w8hgt 0/1 ImagePullBackOff 0
问题似乎与图像拉取有关。就我而言，该图像来自公共 Docker HUB。
是什么导致了图片拉取问题？
这是正在使用的文件。
apiVersion: apps/v1
kind: Deployment
metadata:
name: networkchuckcoffee-deployment
labels:
app: nccoffee
spec:
replicas: 3
selector:
matchLabels:
app: nccoffee
template:
metadata:
labels:
app: nccoffee
spec:
containers:
- name: nccoffee
image: hello-world # initially attempted this image which is also public on DockerHUB -> thenetworkchuck/nccoffee
imagePullPolicy: Always
ports:
- containerPort: 80
Pod 日志。所有 pod 的相同消息：
使用的命令：
kubectl logs some-deployment-857fb6d98b-w8hgt
--
Hello from Docker!
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
(amd64)
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/get-started/
描述日志：（即使这里有敏感数据也不关心，之后会删除此部署）
Name: some-deployment-857fb6d98b-jzwhq
Namespace: default
Priority: 0
Node: app-pool-8nid8/10.106.0.5
Start Time: Sat, 06 Feb 2021 15:45:38 +0000
Labels: app=nccoffee
pod-template-hash=857fb6d98b
Annotations: <none>
Status: Running
IP: 10.244.1.96
IPs:
IP: 10.244.1.96
Controlled By: ReplicaSet/some-deployment-857fb6d98b
Containers:
nccoffee:
Container ID: containerd://beb3b0ac0cd63abc1821e259c0fe24b8d8170bee68d50bffc5590c9154f07ead
Image: hello-world
Image ID: docker.io/library/hello-world@sha256:31b9c7d48790f0d8c50ab433d9c3b7e17666d6993084c002c2ff1ca09b96391d
Port: 80/TCP
Host Port: 0/TCP
State: Waiting
Reason: CrashLoopBackOff
Last State: Terminated
Reason: Completed
Exit Code: 0
Started: Sat, 06 Feb 2021 15:56:40 +0000
Finished: Sat, 06 Feb 2021 15:56:40 +0000
Ready: False
Restart Count: 7
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-n4n95 (ro)
Conditions:
Type Status
Initialized True
Ready False
ContainersReady False
PodScheduled True
Volumes:
default-token-n4n95:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-n4n95
Optional: false
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 13m default-scheduler Successfully assigned default/some-deployment-857fb6d98b-jzwhq to app-pool-8nid8
Normal Pulled 13m kubelet Successfully pulled image "hello-world" in 802.715724ms
Normal Pulled 13m kubelet Successfully pulled image "hello-world" in 766.964136ms
Normal Pulled 12m kubelet Successfully pulled image "hello-world" in 790.211436ms
Normal Created 12m (x4 over 13m) kubelet Created container nccoffee
Normal Pulled 12m kubelet Successfully pulled image "hello-world" in 794.431351ms
Normal Started 12m (x4 over 13m) kubelet Started container nccoffee
Normal Pulling 11m (x5 over 13m) kubelet Pulling image "hello-world"
Normal Pulled 11m kubelet Successfully pulled image "hello-world" in 807.455498ms
Warning BackOff 3m1s (x47 over 13m) kubelet Back-off restarting failed container
答案 0 :(得分：1)
CrashLoopBackoff 是 hello-world 图像的完全正常状态。它旨在打印您在日志中看到的消息，然后退出。它正在做它设计要做的事情。
Kubernetes 部署期望容器保持运行。所以当容器退出时，它会自动重新启动。如果容器一启动就一直退出，则假定它正在崩溃，因此我们得到 CrashLoopBackoff。你需要一个不会退出的容器； hello-world 不是。
正如其他人所提到的，您对 thenetworkchuck/nccoffee 的问题很可能是您已经达到了 DockerHub 的每日拉取限制。
最后，你有四个部署的原因是你没有删除失败的；部署将保持运行直到被删除。 ImagePullBackoff 是 nccoffee 图像，最有可能的是 CrashLoopBackoff 是 hello-world 图像。
kubectl list deployments 将显示您拥有的内容，然后您可以使用 kubectl delete deployment <deployment name>。
或者，kubectl delete -f <file.yaml> 将删除您使用 kubectl apply -f <file.yaml>（或 kubectl create -f ...）