I launched a MongoDB replica set on Kubernetes (GKE as well as kubeadm). I faced no problems with the pods accessing the storage.
However, when I used Helm to deploy the same, I face this problem.
When I run this command-
(
kubectl describe po mongodb-shard1-0 --namespace=kube-system
)
(Here mongodb-shard1-0 is the first and only pod (of the desired three) which was created)
I get the error-
Events
Error: failed to start container "mongodb-shard1-container": Error
response from daemon: error while creating mount source path
'/mongo/data': mkdir /mongo: read-only file system
I noticed one major difference between the two ways of creating MongoDB cluster (without Helm, and with Helm)- when using Helm, I had to create a service account and install the Helm chart using that service account. Without Helm, I did not need that.
I used different mongo docker images, I faced the same error every time.
Can anybody help why I am facing this issue?
Docker exports volumes from filesystem using -v command line option. i.e. -v /var/tmp:/tmp
Can you check if the containers/pods are writing to shared volumes, not to the root filesystem?
Related
I am using PostgreSQL in a pod on a self-hosted Kubernetes 1.23 (using Kubeadm). This pod was configured using the Helm Chart located at https://github.com/bitnami/charts/. I would like to be able to view files within this pod like individual log files (not the one exposed by kubectl logs) in order to find out what is wrong with the information being passed between my Entity Framework Core app and PostgreSQL.
However, this pod does not seem to have the ability to use kubectl exec, which is what I would normally use to view any file within a pod (and is how people seem to suggest doing so online). Is there a way to obtain a copy of or view the files within a pod running in Kubernetes without using kubectl exec, and if so, how would I do so?
Additionally, the storage is managed by Ceph, so I can't easily access the files from the node's filesystem.
I'm trying to connect to a Digital Ocean Kubernates cluster using doctl but when I run
doctl kubernetes cluster kubeconfig save <> I get an error saying .kube/config: not a directory. I've authenticated using doctl and when I run doctl account get I see my account info. I'm confused as to what the problem is. Is this some sort of permission issue or did I miss a config step somewhere?
kubectl (by default) stores a configuration in ${HOME}/.kube/config. It appears you don't have the file and the command doesn't create it if it doesn't exist; I recommend you try creating ${HOME}/.kube first as doctl really ought to create the config file if it doesn't exist.
kubectl facilitates interacting with multiple clusters as multiple users in multiple namespaces through the use a tuple called 'context' which combines a cluster with a user with a(n optional) namespace. The command lets you switch between these easily.
After you're done with a cluster, generally (!) you must tidy up its entires in ${HOME}/.kube/config too as these configs tend to grow over time.
You can change the location of the kubectl config file using an environment variable (KUBECONFIG).
See Organizing Cluster Access Using kubeconfig Files
I'm trying to run the open source cachet status page within Kubernetes via this tutorial https://medium.com/#ctbeke/setting-up-cachet-on-google-cloud-817e62916d48
2 docker containers (cachet/nginx) and Postgres are deployed to a pod on GKE but the cachet container fails with the following CrashLoopBackOff error
Within the docker-compose.yml file its set to APP_KEY=${APP_KEY:-null} and i’m wondering if I didn’t set an environment variable I should have.
Any help with configuring the cachet docker file would be much appreciated! https://github.com/CachetHQ/Docker
Yes, you need to generate a key.
In the entrypoint.sh you can see that the bash script generates a key for you:
https://github.com/CachetHQ/Docker/blob/master/entrypoint.sh#L188-L193
It seems there's a bug in the Dockerfile here. Generate a key manually and then set it as an environment variable in your manifest.
There's a helm chart you can use in development here: https://github.com/apptio/helmcharts/blob/cachet/devel/cachet/templates/secrets.yaml#L12
I am trying to setup Kubernetes for the first time. I am following the Fedora Manual installation guide: http://kubernetes.io/v1.0/docs/getting-started-guides/fedora/fedora_manual_config.html
I am trying to get the kubernetes addons running , specifically the kube-ui. I created the service and replication controller like so:
kubectl create -f cluster/addons/kube-ui/kube-ui-rc.yaml --namespace=kube-system
kubectl create -f cluster/addons/kube-ui/kube-ui-svc.yaml --namespace=kube-system
When i run
kubectl get events --namespace=kube-system
I see errors such as this:
Failed to pull image "gcr.io/google_containers/pause:0.8.0": image pull failed for gcr.io/google_containers/pause:0.8.0, this may be because there are no credentials on this request. details: (Authentication is required.)
How am i supposed to tell kubernetes to authenticate? This isnt covered in the documentation. So how do i fix this?
This happened due to a recent outage to gce storage as a result of which all of us went through this error while pulling images from gcr (which uses gce storage on the backend).
Are you still seeing this error ?
as the message says, you need credentials. Are you using Google Container Engine? Then you need to run
gcloud config set project <your-project>
gcloud config set compute/zone <your-zone, like us-central1-f>
gcloud beta container clusters get-credentials --cluster <your-cluster-name>
then your GCE cluster will have the credentials
I am using instructions from https://github.com/kubernetes/kubernetes/blob/master/docs/getting-started-guides/docker-multinode.md to setup a multinode kubernetes cluster on vmware vcloud infrastructure.
I was able to get the cluster working but when I tried the nfs example I was not able to create the nfs container. So I recreated all the VMs and rebuilt kubernetes from source using:
git clone https://github.com/kubernetes/kubernetes.git
cd kubernetes
sed -i 's/allow_privileged: .*/allow_privileged: true/g' cluster/saltbase/pillar/privilege.sls
./build/run.sh hack/build-cross.sh
cp _output/dockerized/bin/linux/$(dpkg --print-architecture)/kubectl /usr/local/bin
chmod +x /usr/local/bin/kubectl
and continued to setup the kubernetes cluster and retried the NFS example and I get the following error:
kubectl create -f nfs-server-pod.yaml
The Pod "nfs-server" is invalid.
spec.containers[0].securityContext.privileged: forbidden '<*>(0xc20931650c)true'
I tried with both the master and 1.0.3 release and had the same result.
Can you please tell me how to resolve this issue and Thanks for your support
We thought that turning privileged containers off by default would be good for security. It turns out to just be a pain point for a lot of people, so we're working to turn it on by default in kubernetes v1.1.
The --allow-privileged flag has to be set on both the kubelet and the apiserver - please check that