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    Want help with Lab 4.1

    Posts: 4
    in LFS244 Class Forum

    Hello all,
    I would like some help: I cannot get the chart "bitnami/wordpress" running when following the instructions. Here are the technical information:

    I am running a Kubernetes cluster set up with kubeadm on 2 nodes (master and worker) in 2 VMs installed in Google cloud platform

    I do have a StorageClass set as default:

    1. dac@master:~$ k get storageclass
    2. NAME                 PROVISIONER            RECLAIMPOLICY   VOLUMEBINDINGMODE   ALLOWVOLUMEEXPANSION   AGE
    3. standard (default)   kubernetes.io/gce-pd   Delete          Immediate           false                  3h51m

    kube-dns is enabled:

    1. dac@master:~$ k get svc -n kube-system
    2. NAME       TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)                  AGE
    3. kube-dns   ClusterIP   10.96.0.10   <none>        53/UDP,53/TCP,9153/TCP   37d

    But then, when I try to install the chart with

    1. helm install wordpress bitnami/wordpress --version=9.2.5 --set=service.type=NodePort --set=service.nodePorts.http=30001

    both pods are in PENDING state:

    1. dac@master:~$ k get all
    2. NAME                            READY   STATUS    RESTARTS   AGE
    3. ...
    4. pod/wordpress-5c8cc7769-pg8mg   0/1     Pending   0          3h42m
    5. pod/wordpress-mariadb-0         0/1     Pending   0          3h42m
    6. ...

    I tried describing them and got

    1. Events:
    2.   Type     Reason            Age                    From               Message
    3.   ----     ------            ----                   ----               -------
    4.   Warning  FailedScheduling  3h40m (x4 over 3h43m)  default-scheduler  running "VolumeBinding" filter plugin for pod "wordpress-mariadb-0": pod has unbound immediate PersistentVolumeClaims

    and indeed, the PVCs are PENDING:

    1. dac@master:~$ k get pvc
    2. NAME                       STATUS    VOLUME       CAPACITY   ACCESS MODES   STORAGECLASS   AGE
    3. data-wordpress-mariadb-0   Pending                                                         4h8m
    4. wordpress                  Pending                                          standard       3h42m

    🤔 What did I miss?

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    Comments

    • Posts: 2,434

      Hi @dtnguyen,

      It seems your PVs may not be created. And when PVCs are not bound to their respective PVs, the Pods remain in a Pending state, until Kubelet is able to resolve the storage dependency.

      Can you describe the PVC after you try to deploy the chart to see if there are any warnings or errors there?

      Regards,
      -Chris

    • Posts: 4

      Hello @chrispokorni,
      Thank you for your answer. Here are the output:

      1. dac@master:~$ k get pvc
      2. NAME                       STATUS    VOLUME       CAPACITY   ACCESS MODES   STORAGECLASS   AGE
      3. data-wordpress-mariadb-0   Pending                                                         3d21h
      4. registry-claim0            Bound     registryvm   200Mi      RWO                           36d
      5. dac@master:~$ k describe pvc data-wordpress-mariadb-0
      6. Name:          data-wordpress-mariadb-0
      7. Namespace:     default
      8. StorageClass:  
      9. Status:        Pending
      10. Volume:        
      11. Labels:        app=mariadb
      12.                component=master
      13.                heritage=Helm
      14.                release=wordpress
      15. Annotations:   <none>
      16. Finalizers:    [kubernetes.io/pvc-protection]
      17. Capacity:      
      18. Access Modes:  
      19. VolumeMode:    Filesystem
      20. Mounted By:    <none>
      21. Events:
      22.   Type    Reason         Age                      From                         Message
      23.   ----    ------         ----                     ----                         -------
      24.   Normal  FailedBinding  3d21h (x102 over 3d21h)  persistentvolume-controller  no persistent volumes available for this claim and no storage class is set
      25.   Normal  FailedBinding  3d16h (x181 over 3d17h)  persistentvolume-controller  no persistent volumes available for this claim and no storage class is set
      26. ...

      I was aware of this no available PV issue. I lowered PVC spec to adapt to my VMs (a little more than 10 Gi free disk space):

      1. spec: 
      2.   accessModes: 
      3.   - "ReadWriteOnce" 
      4.   resources: 
      5.     requests: 
      6.       storage: "1Gi"

      and launch the app from the generated .yaml template file - but that did not work.

    • Posts: 4
      edited August 2020

      PS: thanks to dynamic provisioning, I do not have to create PVs myself, do I? (Anyway, PV creation is not mentioned in lab instructions).

    • Posts: 2,434

      Hi @dtnguyen,

      It seems that you are not quite following the instructions provided in the lab manual. And you have deviated from the instructions, beginning with the Kubernetes cluster setup. This has implications on most subsequent lab exercises, starting as early as Lab 4.

      The hostpath storage class used in the lab exercise fits the needs of the microk8s cluster. Using a gce-pd provisioned introduces new requirements. And this may or may not work depending on how you bootstrapped your Kubernetes cluster on GCE.

      I would recommend following the lab book instructions from the first lab exercise, so you can focus on learning the new concepts instead of trying to retrofit the exercise to work on your specific environment. Once you have mastered the new concepts, then move to an environment that you may be more familiar with, such as Kubernetes on GCE and possibly gce-pd for storage provisioning.

      Regards,
      -Chris

    • Posts: 4
      edited August 2020

      Once again, I sincerely thank you for your help, and I do think your recommendation is right and I'll follow it.

      I just want to point out that my cluster setting, though somehow deviated from, conforms to the instructions:
      In Section 3 / Introduction /Section overview:
      "If you already have a cluster to use (cloud-based or local), you are more than welcome to use that instead"
      In Lab 3.1 - Creating a New Cluster Using MicroK8s:
      "If you already have an existing cluster, you may opt to skip this section and move on."
      And you understand, when one does things correctly, one expects things to work :smiley: Here it doesn't and I still do not know why. But what you said is absolutely right, let's focus on the point of this course.

    • Posts: 10
      edited November 2021

      Here is one of the option:

      1. Setup a NFS server
        $ showmount -e 192.168.122.64
        Export list for 192.168.122.64:
        /vdb1 *

      2. Setup nfs-subdir-external-provisioner using helm
        Ref: https://kubernetes.io/docs/concepts/storage/storage-classes/#nfs
        Ref: https://github.com/kubernetes-sigs/nfs-subdir-external-provisioner/tree/master/charts/nfs-subdir-external-provisioner
        $ helm repo add nfs-subdir-external-provisioner https://kubernetes-sigs.github.io/nfs-subdir-external-provisioner/
        $ helm install nfs-subdir-external-provisioner nfs-subdir-external-provisioner/nfs-subdir-external-provisioner \
        --set nfs.server=192.168.122.64 \
        --set nfs.path=/vdb1 \
        --set storageClass.defaultClass=true \
        --set storageClass.accessModes=ReadWriteMany

      3. Check the container
        $ k get pods nfs-subdir-external-provisioner-6879c5c6c-6bc9v
        NAME READY STATUS RESTARTS AGE
        nfs-subdir-external-provisioner-6879c5c6c-6bc9v 1/1 Running 0 11m

      4. Check the storageclass
        $ k get storageclasses.storage.k8s.io
        NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
        nfs-client (default) cluster.local/nfs-subdir-external-provisioner Delete Immediate true 12m

      5. Install wordpress and check the pvc
        $ k get pvc
        NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
        data-wordpress-mariadb-0 Bound pvc-a9ac1231-5235-4c04-a8f2-e5fdb66ceab6 8Gi RWO nfs-client 12m
        wordpress Bound pvc-c89c558c-2760-4670-a4b8-3323cb64545d 10Gi RWO nfs-client 12m

      6. Check the pods
        $ k get pods -A | egrep -e '^NAME|wordpress'
        NAMESPACE NAME READY STATUS RESTARTS AGE
        default wordpress-5cbcfd4954-plsl9 1/1 Running 0 14m
        default wordpress-mariadb-0 1/1 Running 0 14m

      My setup (Ubuntu 20.04.3)
      192.168.122.61 control plane
      192.168.122.62 worker
      192.168.122.63 worker
      192.168.122.64 nfs server

    • Posts: 115
      edited August 2022

      @proliant Thanks!

      However, my wordpress container is unhealthy, I get

      Normal Scheduled 4m59s default-scheduler Successfully assigned default/wordpress-7c5694dc6f-b4n57 to k8s-w1
      Normal Pulling 4m58s kubelet Pulling image "docker.io/bitnami/wordpress:6.0.1-debian-11-r20"
      Normal Pulled 4m21s kubelet Successfully pulled image "docker.io/bitnami/wordpress:6.0.1-debian-11-r20" in 36.685555391s
      Normal Created 3m18s (x2 over 4m19s) kubelet Created container wordpress
      Normal Started 3m18s (x2 over 4m19s) kubelet Started container wordpress
      Normal Pulled 3m18s kubelet Container image "docker.io/bitnami/wordpress:6.0.1-debian-11-r20" already present on machine
      Warning Unhealthy 60s (x2 over 70s) kubelet Liveness probe failed: Get "http://192.168.228.98:8080/wp-admin/install.php": dial tcp 192.168.228.98:8080: connect: connection refused
      Warning Unhealthy 52s (x16 over 3m40s) kubelet Readiness probe failed: Get "http://192.168.228.98:8080/wp-login.php": dial tcp 192.168.228.98:8080: connect: connection refused

      It looks like it doesn't have to do with storageClass and PVC

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