Is there any way to clean all cached docker images etc from a kubernetes setup that could free up space on the master nodes?
I try to install a deployment but the kubernetes prompts “no space left on device” while image pulling.
I am kind of surprised that a 80GB disk is not enough for one simple deployment because the cluster is now completely emptied.
Does anyone has an idea on how to wipe all unused docker image etc out?
Thanks a lot!
Successfully pulled image "tensorflow/serving:1.11.1"
Warning Failed 4m30s kubelet, 192.168.10.37 Failed to pull image "gcr.io/kubeflow-images-public/tf-model-server-http-proxy:v20180606-9dfda4f2": rpc error: code = Unknown desc = failed to register layer: Error processing tar file(exit status 1): write /usr/lib/python3.5/idlelib/__pycache__/CodeContext.cpython-35.pyc: no space left on device
Warning Failed 4m27s (x3 over 4m29s) kubelet, 192.168.10.37 Error: ImagePullBackOff
You can run docker image prune to clean up unused images or docker system prune
to cleanup all docker unused resources.
Also you can configure Garbage Collection feature of Kubernetes
Related
I ran my cluster on GKE standard mode
all services is find till i found when try to deploy new servicecs
pod status is always "ContainerCreating"
and when describe it got
Warning FailedMount 0s kubelet MountVolume.SetUp
failed for volume "kube-api-access-gr995" : write
/var/lib/kubelet/pods/867eb785-4347-4439-8a22-1be71d8985f5/volumes/kubernetes.io~projected/kube-api-access-gr995/..2022_07_27_17_22_26.024529456/namespace:
no space left on device
I already try to delete deployments and redeploy again but not work seen like my master is full of disk but i usage GKE so cann't ssh or do something
I'm trying to install and configure Velero for kubernetes backup. I have followed the link to configure it in my GKE cluster. The installation went fine, but velero is not working.
I am using google cloud shell for running all my commands (I have installed and configured velero client in my google cloud shell)
On further inspection on velero deployment and velero pods, I found out that it is not able to pull the image from the docker repository.
kubectl get pods -n velero
NAME READY STATUS RESTARTS AGE
velero-5489b955f6-kqb7z 0/1 Init:ErrImagePull 0 20s
Error from velero pod (kubectl describe pod) (output redacted for readability - only relevant info shown below)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 38s default-scheduler Successfully assigned velero/velero-5489b955f6-kqb7z to gke-gke-cluster1-default-pool-a354fba3-8674
Warning Failed 22s kubelet, gke-gke-cluster1-default-pool-a354fba3-8674 Failed to pull image "velero/velero-plugin-for-gcp:v1.1.0": rpc error: code = Unknown desc = Error response from daemon: Get https://registry-1.docker.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
Warning Failed 22s kubelet, gke-gke-cluster1-default-pool-a354fba3-8674 Error: ErrImagePull
Normal BackOff 21s kubelet, gke-gke-cluster1-default-pool-a354fba3-8674 Back-off pulling image "velero/velero-plugin-for-gcp:v1.1.0"
Warning Failed 21s kubelet, gke-gke-cluster1-default-pool-a354fba3-8674 Error: ImagePullBackOff
Normal Pulling 8s (x2 over 37s) kubelet, gke-gke-cluster1-default-pool-a354fba3-8674 Pulling image "velero/velero-plugin-for-gcp:v1.1.0"
Command used to install velero: (some of the values are given as variables)
velero install \
--provider gcp \
--plugins velero/velero-plugin-for-gcp:v1.1.0 \
--bucket $storagebucket \
--secret-file ~/velero-backup-storage-sa-key.json
Velero Version
velero version
Client:
Version: v1.4.2
Git commit: 56a08a4d695d893f0863f697c2f926e27d70c0c5
<error getting server version: timed out waiting for server status request to be processed>
GKE version
v1.15.12-gke.2
Isn't this a Private Cluster ? – mario 31 mins ago
#mario this is a private cluster but I can deploy other services without any issues (for eg: I have deployed nginx successfully) –
Sreesan 15 mins ago
Well, this is a know limitation of GKE Private Clusters. As you can read in the documentation:
Can't pull image from public Docker Hub
Symptoms
A Pod running in your cluster displays a warning in kubectl describe such as Failed to pull image: rpc error: code = Unknown desc = Error response from daemon: Get https://registry-1.docker.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
Potential causes
Nodes in a private cluster do not have outbound access to the public
internet. They have limited access to Google APIs and services,
including Container Registry.
Resolution
You cannot fetch images directly from Docker Hub. Instead, use images
hosted on Container Registry. Note that while Container Registry's
Docker Hub
mirror
is accessible from a private cluster, it should not be exclusively
relied upon. The mirror is only a cache, so images are periodically
removed, and a private cluster is not able to fall back to Docker Hub.
You can also compare it with this answer.
It can be easily verified on your own by making a simple experiment. Try to run two different nginx deployments. First based on image nginx (which equals to nginx:latest) and the second one based on nginx:1.14.2.
While the first scenario is perfectly feasible because the nginx:latest image can be pulled from Container Registry's Docker Hub mirror which is accessible from a private cluster, any attempt of pulling nginx:1.14.2 will fail which you'll see in Pod events. It happens because the kubelet is not able to find this version of the image in GCR and it tries to pull it from public docker registry (https://registry-1.docker.io/v2/), which in Private Clusters is not possible. "The mirror is only a cache, so images are periodically removed, and a private cluster is not able to fall back to Docker Hub." - as you can read in docs.
If you still have doubts, just ssh into your node and try to run following commands:
curl https://cloud.google.com/container-registry/
curl https://registry-1.docker.io/v2/
While the first one works perfectly, the second one will eventually fail:
curl: (7) Failed to connect to registry-1.docker.io port 443: Connection timed out
Reason ? - "Nodes in a private cluster do not have outbound access to the public internet."
Solution ?
You can search what is currently available in GCR here.
In many cases you should be able to get the required image if you don't specify it's exact version (by default latest tag is used). While it can help with nginx, unfortunatelly no version of velero/velero-plugin-for-gcp is currently available in Google Container Registry's Docker Hub mirror.
Granting private nodes outbound internet access by using Cloud NAT seems the only reasonable solution that can be applied in your case.
I solved this problem by realizing that version of:
velero/velero-plugin-for-gcp
is not following the version of:
velero/velero
For example, now latest versions are:
velero/velero:v1.9.1 and velero/velero-plugin-for-gcp:v1.5.0
I have an image of size of 6.5GB in the Google Container Registry. When I try to pull the image on a Kubernetes cluster node(worker node) via a deployment, an error occurs: ErrImagePull(or sometimes ImagePullBackOff). I used the describe command to see the error in detail. The error is described as Failed to pull image "gcr.io/.../.. ": rpc error: code = Canceled desc = context canceled
What may be the issue and how to mitigate it?
It seems that the kubelet expects a updates on progress during the pull of a large image but this currently isn't available by default with most container registries. It's not ideal behaviour but it appears people have been able to work around it from reading the responses on https://github.com/kubernetes/kubernetes/issues/59376 and Kubernetes set a timeout limit on image pulls by adjusting the timeout
Use --image-pull-progress-deadline duration as a parameter when you start the kubelet.
This is documented in the kubelet documentation.
If no pulling progress is made before this deadline, the image pulling will be cancelled. (default 1m0s)
Have create updated image with new tag for rolling but then while performing update with this command: kubectl set image deployments/hello-node-1 hello-node-1=hello-node:v2
Getting error: kubelet, minikube Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "hello-node-1" with ErrImagePull: "rpc error: code = 2 desc = Error: image library/hello-node not found"
It looks like you didn't set the image correctly. Did you push it to the correct repository? A way to test it could be to create a new deployment that uses your newly created image.
You are referring to the wrong image. The error message shows that the kubelet is attempting to pull hello-node:v2 as an official image from docker hub (library/...).
If you did push your image to docker hub then prefix the image name with your docker hub username.
If this is in some private repository then prefix it with a repository hostname.
If you built the image locally on the node then make sure your imagePullPolicy in your Deployment is set to IfNotPresent and make sure the image is actually present on all nodes this pod might be scheduled to run on.
For minikube check out this post.
When deploying a service to Kubernetes/GKE kubectl describe pod indicates the following error (as occurring after the image was successfully pulled):
{kubelet <id>} Warning FailedSync Error syncing pod,
skipping: failed to "StartContainer" for "<id>" with CrashLoopBackOff:
"Back-off 20s restarting failed container=<id>"
{kubelet <id>}
spec.containers{id} Warning BackOff restarting failed docker container.
I have checked various log files (such as /var/log/kubelet.log and /var/log/docker.log) on the node where the pod is executing but did not find anything more specific?
What does the error message indicate, and how can I further diagnose and solve the problem?
The problem might be in relation to mounting a PD. I can both successfully docker run the the image from Cloud Shell (without the PD) and mount the PD after adding it to GCE VM instance. So apparently it's neither caused by the image nor the PD in isolation.
The root cause for this was apparently that the PD did not contain a directory which was the target of a symbolic link required by the application running inside the image. This cause the application to terminate and as an effect the image to stop, which apparently was reported as failed docker container in the shown log file.
After creating the directory (by attatching the drive to a separate VM instance and mounting it there just for that purpose) this specific problem disappears (only to be followed by this one for now :)