K
Q

Mounting Azure File Storage in Docker container via Kubernetes

6/22/2017

I am attempting to mount my Azure File Storage to a container using the method found here: https://github.com/kubernetes/kubernetes/tree/master/examples/volumes/azure_file

Upon pod creation I am getting the error: "Output: mount error: could not resolve address for [encoded name of my file storage].file.core.windows.net: Unknown error"

I have confirmed that my File Storage resource and the VM hosting the pod are in the same Azure location (East US). I am able to mount this share manually on the VM hosting the pod using the same address in the error above. Is it possible I am missing some sort of configuration in my container that is not explained in the Git Hub tutorial?

I have tried creating my container without specifying the volume and was able to ping the address for the file storage from within the container so I am not sure where the cannot resolve address error is coming from.

-- CAmoruso
azure
docker
kubernetes
smb

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3 Answers

6/23/2017

I can't reproduce your error, but we can follow those steps to mount Azure file share to k8s container.
1.create k8s via Azure new portal.
2.SSH k8s master, create secret, create secret by k8s file:

In this yaml file, we should write storage account and key in it, and we should base64 encoded Azure storage account and key, like this:

root@k8s-master-3CC6E803-0:~# echo -n jasonshare321 | base64
amFzb25zaGFyZTMyMQ==
root@k8s-master-3CC6E803-0:~# echo -n Bnbh0fjykD+b/EveNoR/elOp118+0vmLsbQqVGC3H0W23mSfbH9WfV1A60Qw3CAZ70Tm4Wgpse1LEtgSJF27cQ== | base64
Qm5iaDBmanlrRCtiL0V2ZU5vUi9lbE9wMTE4KzB2bUxzYlFxVkdDM0gwVzIzbVNmYkg5V2ZWMUE2MFF3M0NBWjcwVG00V2dwc2UxTEV0Z1NKRjI3Y1E9PQ==

Then create azure-secret:

root@k8s-master-3CC6E803-0:~# mkdir /azure_file
root@k8s-master-3CC6E803-0:~# cd /azure_file/
root@k8s-master-3CC6E803-0:/azure_file# touch azure-secret.yaml
root@k8s-master-3CC6E803-0:/azure_file# vi azure-secret.yaml

Here is the azure-secret:

root@k8s-master-3CC6E803-0:/azure_file# cat azure-secret.yaml

apiVersion: v1
kind: Secret
metadata:
  name: azure-secret
type: Opaque
data:
  azurestorageaccountname: amFzb25zaGFyZTMyMQ== 
  azurestorageaccountkey: Qm5iaDBmanlrRCtiL0V2ZU5vUi9lbE9wMTE4KzB2bUxzYlFxVkdDM0gwVzIzbVNmYkg5V2ZWMUE2MFF3M0NBWjcwVG00V2dwc2UxTEV0Z1NKRjI3Y1E9PQ==

Then use kubectl to create secret,like this:

root@k8s-master-3CC6E803-0:/azure_file# kubectl create -f /azure_file/azure-secret.yaml 
secret "azure-secret" created
root@k8s-master-3CC6E803-0:/azure_file# kubectl get secret
NAME                  TYPE                                  DATA      AGE
azure-secret          Opaque                                2         11s
default-token-07cd5   kubernetes.io/service-account-token   3         35m

3.Create pod: create azure.yaml:

root@k8s-master-3CC6E803-0:/azure_file# touch azure.yaml
root@k8s-master-3CC6E803-0:/azure_file# vi azure.yaml 
apiVersion: v1
kind: Pod
metadata:
 name: nginx
spec:
 containers:
  - image: nginx
    name: nginx
    volumeMounts:
      - name: azure
        mountPath: /mnt/azure
 volumes:
      - name: azure
        azureFile:
          secretName: azure-secret
          shareName: testfileshare
          readOnly: false

Use this file to create pod:

root@k8s-master-3CC6E803-0:/azure_file# kubectl create -f /azure_file/azure.yaml 
pod "nginx" created
root@k8s-master-3CC6E803-0:/azure_file# kubectl get pods
NAME      READY     STATUS    RESTARTS   AGE
nginx     1/1       Running   0          17s

Now, pod create is completed, we can use this script to check file,like this:

root@k8s-master-3CC6E803-0:/azure_file# kubectl exec -it nginx bash
root@nginx:/# ls                                                                                                         
bin  boot  dev  etc  home  lib  lib32  lib64  libx32  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
root@nginx:/# cd /mnt
root@nginx:/mnt# ls
azure
root@nginx:/mnt# cd azure
root@nginx:/mnt/azure# ls
root@nginx:/mnt/azure# df -Th
Filesystem                                          Type     Size  Used Avail Use% Mounted on
overlay                                             overlay   30G  3.3G   26G  12% /
tmpfs                                               tmpfs    1.7G     0  1.7G   0% /dev
tmpfs                                               tmpfs    1.7G     0  1.7G   0% /sys/fs/cgroup
/dev/sda1                                           ext4      30G  3.3G   26G  12% /etc/hosts
//jasonshare321.file.core.windows.net/testfileshare cifs      50G     0   50G   0% /mnt/azure
shm                                                 tmpfs     64M     0   64M   0% /dev/shm
tmpfs                                               tmpfs    1.7G   12K  1.7G   1% /run/secrets/kubernetes.io/serviceaccount

Note:
1.We should base64 encoded Azure storage account and key.
2.write the right file share name to azure.yaml:enter image description here

-- Jason Ye
Source: StackOverflow
2/8/2018

Remember to use flag -n to avoid echoing trailing characters: echo -n foobarbaz | base64

-- chribsen
Source: StackOverflow
10/25/2017

There is also dynamic provisioning for azure file mount feature, you could find complete examples here: https://github.com/andyzhangx/demo/tree/master/linux/azurefile

-- andy zhang
Source: StackOverflow