为什么启动 daskdev/dask 到 Pod 会失败？

Question

为什么 kubectl run dask --image daskdev/dask 失败？

# starting the container with docker to make sure it basically works
➜  ~ docker run --rm -it --entrypoint bash daskdev/dask:latest
(base) root@5b34ce038eb3:/# python
Python 3.8.0 (default, Nov  6 2019, 21:49:08) 
[GCC 7.3.0] :: Anaconda, Inc. on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import dask
>>> 
>>> exit()
(base) root@5b34ce038eb3:/# exit
exit

# now trying to fire up the container on a minikube cluster
➜  ~ kubectl run dask --image daskdev/dask  
pod/dask created

# let's see what's going on with the Pod
➜  ~ kubectl get pods -w
NAME                              READY   STATUS             RESTARTS   AGE
dask                              0/1     CrashLoopBackOff   1          13s
dask                              0/1     Completed          2          24s
dask                              0/1     CrashLoopBackOff   2          38s

# not sure why the logs look like something is missing
➜  ~ kubectl logs dask --tail=100
+ '[' '' ']'
+ '[' -e /opt/app/environment.yml ']'
+ echo 'no environment.yml'
+ '[' '' ']'
+ '[' '' ']'
+ exec
no environment.yml

Answer 1

所以基本上，如果你检查 kubectl describe pod dask 的结果，你会看到最后一个状态是 Terminated，退出代码为 0，这实际上意味着你的容器已成功启动，它是否工作并且完成也顺利。您还希望 pod 发生什么？此外，当您使用 kubectl run dask --image daskdev/dask 创建 pod 时，它默认使用 restartPolicy: Always 创建！！！！

Always 表示容器即使以零退出代码退出（即成功）也会重新启动.

    State:          Waiting
      Reason:       CrashLoopBackOff
    Last State:     Terminated
      Reason:       Completed
      Exit Code:    0
      Started:      Fri, 02 Apr 2021 15:06:00 +0000
      Finished:     Fri, 02 Apr 2021 15:06:00 +0000
    Ready:          False
    Restart Count:  3
    Environment:    <none>

您的容器中没有/opt/app/environment.yml。如果我没记错的话，你应该先用 prepare.sh. PLease check more here - DASK 配置它节

#docker run --rm -it --entrypoint bash daskdev/dask:latest
(base) root@431d69bb9a80:/# ls -la /opt/app/
total 12
drwxr-xr-x 2 root root 4096 Mar 27 15:43 .
drwxr-xr-x 1 root root 4096 Mar 27 15:43 ..

not sure why the logs look like something is missing ➜ ~ kubectl logs dask --tail=100 ... exec no environment.yml

已经准备好了helm DASK chart。用它。它工作正常：

helm repo add dask https://helm.dask.org/
helm repo update
helm install raffael-dask-release dask/dask

NAME: raffael-dask-release
LAST DEPLOYED: Fri Apr  2 15:43:38 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
Thank you for installing DASK, released at name: raffael-dask-release.

This release includes a Dask scheduler, 3 Dask workers, and 1 Jupyter servers.

The Jupyter notebook server and Dask scheduler expose external services to
which you can connect to manage notebooks, or connect directly to the Dask
cluster. You can get these addresses by running the following:

  export DASK_SCHEDULER="127.0.0.1"
  export DASK_SCHEDULER_UI_IP="127.0.0.1"
  export DASK_SCHEDULER_PORT=8080
  export DASK_SCHEDULER_UI_PORT=8081
  kubectl port-forward --namespace default svc/raffael-dask-release-scheduler $DASK_SCHEDULER_PORT:8786 &
  kubectl port-forward --namespace default svc/raffael-dask-release-scheduler $DASK_SCHEDULER_UI_PORT:80 &

  export JUPYTER_NOTEBOOK_IP="127.0.0.1"
  export JUPYTER_NOTEBOOK_PORT=8082
  kubectl port-forward --namespace default svc/raffael-dask-release-jupyter $JUPYTER_NOTEBOOK_PORT:80 &

  echo tcp://$DASK_SCHEDULER:$DASK_SCHEDULER_PORT               -- Dask Client connection
  echo http://$DASK_SCHEDULER_UI_IP:$DASK_SCHEDULER_UI_PORT     -- Dask dashboard
  echo http://$JUPYTER_NOTEBOOK_IP:$JUPYTER_NOTEBOOK_PORT       -- Jupyter notebook

NOTE: It may take a few minutes for the LoadBalancer IP to be available. Until then, the commands above will not work for the LoadBalancer service type.
You can watch the status by running 'kubectl get svc --namespace default -w raffael-dask-release-scheduler'

NOTE: It may take a few minutes for the URLs above to be available if any EXTRA_PIP_PACKAGES or EXTRA_CONDA_PACKAGES were specified,
because they are installed before their respective services start.

NOTE: The default password to login to the notebook server is `dask`. To change this password, refer to the Jupyter password section in values.yaml, or in the README.md.

如果您仍然想手动创建 pod，请使用下面的...主要思想已设置 restartPolicy: Never。

apiVersion: v1
kind: Pod
metadata:
  name: dask-tesssssst
  labels:
    foo: bar
spec:
  restartPolicy: Never
  containers:
  - image: daskdev/dask:latest
    imagePullPolicy: Always
    name: dask-tesssssst

请检查 DASK KubeCluster official documentation for more examples. 我从那里截取的最后一张。

为什么启动 daskdev/dask 到 Pod 会失败？

Why does starting daskdev/dask into a Pod fail?

kubernetes

dask

dask-kubernetes