vSphere with Tanzu using NSX-T - Part28 - Create a custom VM Class

A VM class is a template that defines CPU, memory, and reservations for VMs. If you want to create a custom vmclass you can use dcli or vSphere UI. 

Following is an example using dcli:

❯ dcli +server vcenter-server-fqdn +skip-server-verification com vmware vcenter namespacemanagement virtualmachineclasses create --id best-effort-16xlarge --cpu-count 64 --memory-mb 131072

This will create a vmclass with 64 vCPUs and 128GB memory with no reservations.

❯ dcli +server vcenter-server-fqdn +skip-server-verification com vmware vcenter namespacemanagement virtualmachineclasses create --id guaranteed-16xlarge --cpu-count 64 --memory-mb 131072 --cpu-reservation 100 --memory-reservation 100

This will create a vmclass with 64 vCPUs and 128GB memory with 100% reservations.

Note: You will need to attach this newly created vmclass to a supervisor namespace to use it.

Here is the documentation reference: https://docs.vmware.com/en/VMware-vSphere/8.0/vsphere-with-tanzu-services-workloads/GUID-18C7B2E3-BCF5-488C-9C50-937E29BB0C48.html

Hope it was useful. Cheers!

vSphere with Tanzu using NSX-T - Part26 - Jumpbox kubectl plugin to SSH to TKC node

For troubleshooting TKC (Tanzu Kubernetes Cluster) you may need to ssh into the TKC nodes. For doing ssh, you will need to first create a jumpbox pod under the supervisor namespace and from there you can ssh to the TKC nodes.

Here is the manual procedure: https://docs.vmware.com/en/VMware-vSphere/7.0/vmware-vsphere-with-tanzu/GUID-587E2181-199A-422A-ABBC-0A9456A70074.html

Following kubectl plugin creats a jumpbox pod under a supervisor namespace. You can exec into this jumpbox pod to ssh into the TKC VMs.

kubectl-jumpbox

#!/bin/bash

Help()
{
   # Display Help
   echo "Description: This plugin creats a jumpbox pod under a supervisor namespace. You can exec into this jumpbox pod to ssh into the TKC VMs."
   echo "Usage: kubectl jumpbox SVNAMESPACE TKCNAME"
   echo "Example: k exec -it jumpbox-tkc1 -n svns1 -- /usr/bin/ssh vmware-system-user@VMIP"
}

# Get the options
while getopts ":h" option; do
   case $option in
      h) # display Help
         Help
         exit;;
     \?) # incorrect option
         echo "Error: Invalid option"
         exit;;
   esac
done

kubectl create -f - <<EOF
apiVersion: v1
kind: Pod
metadata:
  name: jumpbox-$2
  namespace: $1           #REPLACE
spec:
  containers:
  - image: "photon:3.0"
    name: jumpbox
    command: [ "/bin/bash", "-c", "--" ]
    args: [ "yum install -y openssh-server; mkdir /root/.ssh; cp /root/ssh/ssh-privatekey /root/.ssh/id_rsa; chmod 600 /root/.ssh/id_rsa; while true; do sleep 30; done;" ]
    volumeMounts:
      - mountPath: "/root/ssh"
        name: ssh-key
        readOnly: true
    resources:
      requests:
        memory: 2Gi
  
  volumes:
    - name: ssh-key
      secret:
        secretName: $2-ssh     #REPLACE YOUR-CLUSTER-NAME-ssh 

  
EOF

Usage

• Place the plugin in the system executable path.
• I placed it in $HOME/.krew/bin directory in my laptop.
• Once you copied the plugin to the proper path, you can make it executable by: chmod 755 kubectl-jumpbox
• After that you should be able to run the plugin as: kubectl jumpbox SUPERVISORNAMESPACE TKCNAME

 

Example

❯ kg tkc -n vineetha-dns1-test
NAME               CONTROL PLANE   WORKER   TKR NAME                           AGE    READY   TKR COMPATIBLE   UPDATES AVAILABLE
tkc                1               3        v1.21.6---vmware.1-tkg.1.b3d708a   213d   True    True             [1.22.9+vmware.1-tkg.1.cc71bc8]
tkc-using-cci-ui   1               1        v1.23.8---vmware.3-tkg.1           37d    True    True
❯
❯ kg po -n vineetha-dns1-test
NAME         READY   STATUS    RESTARTS   AGE
nginx-test   1/1     Running   0          29d
❯
❯
❯ kubectl jumpbox vineetha-dns1-test tkc
pod/jumpbox-tkc created
❯
❯ kg po -n vineetha-dns1-test
NAME          READY   STATUS    RESTARTS   AGE
jumpbox-tkc   0/1     Pending   0          8s
nginx-test    1/1     Running   0          29d
❯
❯ kg po -n vineetha-dns1-test
NAME          READY   STATUS    RESTARTS   AGE
jumpbox-tkc   1/1     Running   0          21s
nginx-test    1/1     Running   0          29d
❯
❯ k jumpbox -h
Description: This plugin creats a jumpbox pod under a supervisor namespace. You can exec into this jumpbox pod to ssh into the TKC VMs.
Usage: kubectl jumpbox SVNAMESPACE TKCNAME
Example: k exec -it jumpbox-tkc1 -n svns1 -- /usr/bin/ssh vmware-system-user@VMIP
❯
❯ kg vm -n vineetha-dns1-test -o wide
NAME                                                              POWERSTATE   CLASS               IMAGE                                                       PRIMARY-IP      AGE
tkc-control-plane-8rwpk                                           poweredOn    best-effort-small   ob-18900476-photon-3-k8s-v1.21.6---vmware.1-tkg.1.b3d708a   172.29.0.7      133d
tkc-using-cci-ui-control-plane-z8fkt                              poweredOn    best-effort-small   ob-20953521-tkgs-ova-photon-3-v1.23.8---vmware.3-tkg.1      172.29.13.130   37d
tkc-using-cci-ui-tkg-cluster-nodepool-9nf6-n6nt5-b97c86fb45mvgj   poweredOn    best-effort-small   ob-20953521-tkgs-ova-photon-3-v1.23.8---vmware.3-tkg.1      172.29.13.131   37d
tkc-workers-zbrnv-6c98dd84f9-52gn6                                poweredOn    best-effort-small   ob-18900476-photon-3-k8s-v1.21.6---vmware.1-tkg.1.b3d708a   172.29.0.6      133d
tkc-workers-zbrnv-6c98dd84f9-d9mm7                                poweredOn    best-effort-small   ob-18900476-photon-3-k8s-v1.21.6---vmware.1-tkg.1.b3d708a   172.29.0.8      133d
tkc-workers-zbrnv-6c98dd84f9-kk2dg                                poweredOn    best-effort-small   ob-18900476-photon-3-k8s-v1.21.6---vmware.1-tkg.1.b3d708a   172.29.0.3      133d
❯
❯ k exec -it jumpbox-tkc -n vineetha-dns1-test -- /usr/bin/ssh vmware-system-user@172.29.0.7
The authenticity of host '172.29.0.7 (172.29.0.7)' can't be established.
ECDSA key fingerprint is SHA256:B7ptmYm617lFzLErJm7G5IdT7y4SJYKhX/OenSgguv8.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.29.0.7' (ECDSA) to the list of known hosts.
Welcome to Photon 3.0 (\m) - Kernel \r (\l)
 13:06:06 up 133 days,  4:46,  0 users,  load average: 0.23, 0.33, 0.27

36 Security notice(s)
Run 'tdnf updateinfo info' to see the details.
vmware-system-user@tkc-control-plane-8rwpk [ ~ ]$ sudo su
root [ /home/vmware-system-user ]#
root [ /home/vmware-system-user ]#

Hope it was useful. Cheers!

vSphere with Tanzu using NSX-T - Part25 - Spherelet

The Spherelet is based on the Kubernetes “Kubelet” and enables an ESXi hypervisor to act as a Kubernetes worker node. Sometimes you may notice that the worker nodes of your supervisor cluster are having NotReady,SchedulingDisabled status, and it maybe becuase spherelet is not running on those ESXi nodes.

Following are the steps to verify the status of spherelet service, and restart them if required.

Example:

❯ kubectx wdc-01-vcxx
Switched to context "wdc-01-vcxx".
❯ kubectl get node
NAME                               STATUS                        ROLES                  AGE    VERSION
42019f7e751b2818bb0c659028d49fdc   Ready                         control-plane,master   317d   v1.22.6+vmware.wcp.2
4201b0b21aed78d8e72bfb622bb8b98b   Ready                         control-plane,master   317d   v1.22.6+vmware.wcp.2
4201c53dcef2701a8c36463942d762dc   Ready                         control-plane,master   317d   v1.22.6+vmware.wcp.2
wdc-01-rxxesx04.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx05.xxxxxxxxx.com      NotReady,SchedulingDisabled   agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx06.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx32.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx33.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx34.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx35.xxxxxxxxx.com      Ready,SchedulingDisabled      agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx36.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx37.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx38.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx39.xxxxxxxxx.com      NotReady,SchedulingDisabled   agent                  317d   v1.22.6-sph-db56d46
wdc-01-rxxesx40.xxxxxxxxx.com      Ready                         agent                  317d   v1.22.6-sph-db56d46

Logs

• ssh into the ESXi worker node.

tail -f /var/log/spherelet.log 

Status

• ssh into the ESXi worker node and run the following:
  

etc/init.d/spherelet status

•  You can check status of spherelet using PowerCLI. Following is an example:

> Connect-VIServer wdc-10-vcxx

> Get-VMHost | Get-VMHostService | where {$_.Key -eq "spherelet"}  | select VMHost,Key,Running | ft

VMHost                        Key       Running
------                        ---       -------
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True
wdc-10-r0xxxxxxxxxxxxxxxxxxxx spherelet    True

Restart

• ssh into the ESXi worker node and run the following:
  

/etc/init.d/spherelet restart

• You can also restart spherelet service using PowerCLI. Following is an example to restart spherelet service on ALL the ESXi worker nodes of a cluster:

> Get-Cluster

Name                           HAEnabled  HAFailover DrsEnabled DrsAutomationLevel
                                          Level
----                           ---------  ---------- ---------- ------------------
wdc-10-vcxxc01                 True       1          True       FullyAutomated

> Get-Cluster -Name wdc-10-vcxxc01 | Get-VMHost | foreach { Restart-VMHostService -HostService ($_ | Get-VMHostService | where {$_.Key -eq "spherelet"}) }

Certificates

You may notice the ESXi worker nodes in NotReady state when the following spherelet certs expire.

• /etc/vmware/spherelet/spherelet.crt
• /etc/vmware/spherelet/client.crt

 

An example is given below:

❯ kg no
NAME                               STATUS     ROLES                  AGE    VERSION
420802008ec0d8ccaa6ac84140768375   Ready      control-plane,master   70d    v1.22.6+vmware.wcp.2
42087a63440b500de6cec759bb5900bf   Ready      control-plane,master   77d    v1.22.6+vmware.wcp.2
4208e08c826dfe283c726bc573109dbb   Ready      control-plane,master   77d    v1.22.6+vmware.wcp.2
wdc-08-rxxesx25.xxxxxxxxx.com      NotReady   agent                  370d   v1.22.6-sph-db56d46
wdc-08-rxxesx26.xxxxxxxxx.com      NotReady   agent                  370d   v1.22.6-sph-db56d46
wdc-08-rxxesx23.xxxxxxxxx.com      NotReady   agent                  370d   v1.22.6-sph-db56d46
wdc-08-rxxesx24.xxxxxxxxx.com      NotReady   agent                  370d   v1.22.6-sph-db56d46
wdc-08-rxxesx25.xxxxxxxxx.com      NotReady   agent                  370d   v1.22.6-sph-db56d46
wdc-08-rxxesx26.xxxxxxxxx.com      NotReady   agent                  370d   v1.22.6-sph-db56d46

You can ssh into the ESXi worker nodes and verify the validity of the above mentioned certs. They have a life time of one year.

 

Example:

[root@wdc-08-rxxesx25:~] openssl x509 -enddate -noout -in /etc/vmware/spherelet/spherelet.crt
notAfter=Sep  1 08:32:24 2023 GMT
[root@wdc-08-rxxesx25:~] openssl x509 -enddate -noout -in /etc/vmware/spherelet/client.crt
notAfter=Sep  1 08:32:24 2023 GMT

Depending on your support contract, if its a production environment you may need to open a case with VMware GSS for resolving this issue. 

 

Ref KBs: 

• https://kb.vmware.com/s/article/89324
• https://kb.vmware.com/s/article/90627 
  

Verify

❯ kubectl get node
NAME                               STATUS   ROLES                  AGE     VERSION
42017dcb669bea2962da27fc2f6c16d2   Ready    control-plane,master   5d20h   v1.23.12+vmware.wcp.1
4201b763c766875b77bcb9f04f8840b3   Ready    control-plane,master   5d21h   v1.23.12+vmware.wcp.1
4201dab068e9b2d3af3b8fde450b3d96   Ready    control-plane,master   5d20h   v1.23.12+vmware.wcp.1
wdc-01-rxxesx04.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx05.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx06.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx32.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx33.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx34.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx35.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx36.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx37.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx38.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx39.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
wdc-01-rxxesx40.xxxxxxxxx.com      Ready    agent                  5d19h   v1.23.5-sph-81ef5d1
   

Hope it was useful. Cheers!

vSphere with Tanzu using NSX-T - Part24 - Kubernetes component certs in TKC

The Kubernetes component certificates inside a TKC (Tanzu Kubernetes Cluster) has lifetime of 1 year. If you manage to upgrade your TKC atleast once a year, these certs will get rotated automatically. 

 

IMPORTANT NOTES: 

• As per this VMware KB, if TKGS Guest Cluster certificates are expired, you will need to engage VMware support to manually rotate them.  
• Following troubleshooting steps and workaround are based on studies conducted on my dev/ test/ lab setup, and I will NOT recommend anyone to follow these on your production environment.
  

 

Symptom:

❯ KUBECONFIG=tkc.kubeconfig kubectl get nodes
Unable to connect to the server: x509: certificate has expired or is not yet valid

 

Troubleshooting:

• Verify the certificate expiry of the tkc kubeconfig file itself.

❯ grep client-certificate-data tkc.kubeconfig | awk '{print $2}' | base64 -d | openssl x509 -noout -dates
notBefore=Mar  8 18:10:15 2022 GMT
notAfter=Mar  7 18:26:10 2024 GMT

• Create a jumpbox pod and ssh to TKC control plane nodes.
• Verify system pods and check logs from apiserver and etcd pods. Sample etcd pod logs are given below:

2023-04-11 07:09:00.268792 W | rafthttp: health check for peer b5bab7da6e326a7c could not connect: x509: certificate has expired or is not yet valid: current time 2023-04-11T07:08:57Z is after 2023-04-06T06:17:56Z
2023-04-11 07:09:00.268835 W | rafthttp: health check for peer b5bab7da6e326a7c could not connect: x509: certificate has expired or is not yet valid: current time 2023-04-11T07:08:57Z is after 2023-04-06T06:17:56Z
2023-04-11 07:09:00.268841 W | rafthttp: health check for peer 19b6b0bf00e81f0b could not connect: remote error: tls: bad certificate
2023-04-11 07:09:00.268869 W | rafthttp: health check for peer 19b6b0bf00e81f0b could not connect: remote error: tls: bad certificate
2023-04-11 07:09:00.310030 I | embed: rejected connection from "172.31.20.27:35362" (error "remote error: tls: bad certificate", ServerName "")
2023-04-11 07:09:00.312806 I | embed: rejected connection from "172.31.20.27:35366" (error "remote error: tls: bad certificate", ServerName "")
2023-04-11 07:09:00.321449 I | embed: rejected connection from "172.31.20.19:35034" (error "remote error: tls: bad certificate", ServerName "")
2023-04-11 07:09:00.322192 I | embed: rejected connection from "172.31.20.19:35036" (error "remote error: tls: bad certificate", ServerName "")

• Verify whether admin.conf inside the control plane node has expired.

root [ /etc/kubernetes ]# grep client-certificate-data admin.conf | awk '{print $2}' | base64 -d | openssl x509 -noout -dates
notBefore=Mar  8 18:10:15 2022 GMT
notAfter=Apr  6 06:05:46 2023 GMT

• Verify Kubernetes component certs in all the control plane nodes.

root [ /etc/kubernetes ]# kubeadm certs check-expiration
[check-expiration] Reading configuration from the cluster...
[check-expiration] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[check-expiration] Error reading configuration from the Cluster. Falling back to default configuration

CERTIFICATE                EXPIRES                  RESIDUAL TIME   CERTIFICATE AUTHORITY   EXTERNALLY MANAGED
admin.conf                 Apr 06, 2023 06:05 UTC   <invalid>                               no
apiserver                  Apr 06, 2023 06:05 UTC   <invalid>       ca                      no
apiserver-etcd-client      Apr 06, 2023 06:05 UTC   <invalid>       etcd-ca                 no
apiserver-kubelet-client   Apr 06, 2023 06:05 UTC   <invalid>       ca                      no
controller-manager.conf    Apr 06, 2023 06:05 UTC   <invalid>                               no
etcd-healthcheck-client    Apr 06, 2023 06:05 UTC   <invalid>       etcd-ca                 no
etcd-peer                  Apr 06, 2023 06:05 UTC   <invalid>       etcd-ca                 no
etcd-server                Apr 06, 2023 06:05 UTC   <invalid>       etcd-ca                 no
front-proxy-client         Apr 06, 2023 06:05 UTC   <invalid>       front-proxy-ca          no
scheduler.conf             Apr 06, 2023 06:05 UTC   <invalid>                               no

CERTIFICATE AUTHORITY   EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
ca                      Mar 05, 2032 18:15 UTC   8y              no
etcd-ca                 Mar 05, 2032 18:15 UTC   8y              no
front-proxy-ca          Mar 05, 2032 18:15 UTC   8y              no

 

Workaround:

• Renew Kubernetes component certs on control plane nodes if expired using kubeadm certs renew all.

root [ /etc/kubernetes ]# kubeadm certs renew all
[renew] Reading configuration from the cluster...
[renew] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[renew] Error reading configuration from the Cluster. Falling back to default configuration

certificate embedded in the kubeconfig file for the admin to use and for kubeadm itself renewed
certificate for serving the Kubernetes API renewed
certificate the apiserver uses to access etcd renewed
certificate for the API server to connect to kubelet renewed
certificate embedded in the kubeconfig file for the controller manager to use renewed
certificate for liveness probes to healthcheck etcd renewed
certificate for etcd nodes to communicate with each other renewed
certificate for serving etcd renewed
certificate for the front proxy client renewed
certificate embedded in the kubeconfig file for the scheduler manager to use renewed

Done renewing certificates. You must restart the kube-apiserver, kube-controller-manager, kube-scheduler and etcd, so that they can use the new certificates.

 

Verify:

• Verify using the following steps on all the TKC control plane nodes.
  

root [ /etc/kubernetes ]# grep client-certificate-data admin.conf | awk '{print $2}' | base64 -d | openssl x509 -noout -dates

root [ /etc/kubernetes ]# kubeadm certs check-expiration

• Try connect to the TKC using tkc.kubeconfig.

KUBECONFIG=tkc.kubeconfig kubectl get node

Hope it was useful. Cheers!

References: 

• https://kb.vmware.com/s/article/86251

• https://kb.vmware.com/s/article/89324

vSphere with Tanzu using NSX-T - Part21 - Pointers while upgrading the stack

Here are some pointers.

The main workflow while upgrading the entire stack is:

1. upgrade NSX-T
2. upgrade vCenter server
3. upgrade ESXi nodes
4. upgrade vSAN and vDS (if required)
5. upgrade WCP

Note: Make sure you follow the compatibility matrix while performing upgrades in a production environment.

NSX-T

While NSX-T is getting upgraded, the host transport nodes will also need to be updated. NSX components will be installed/ updated on the ESXi nodes and may need a reboot also. 

In NSX-T: System > Lifecycle Management > Upgrade > Upgrade NSX > Hosts

Plan

-Upgrade order across groups - Serial

-Pause upgrade condition - When an upgrade unit fails to upgrade

Host Groups

-Upgrade order within group - Serial

-Upgrade mode - Maintenance

 

Notes: 

• There is an in-place upgrade mode for the host groups, and in this mode the NSX component on the ESXi nodes will get updated first and then the node will be placed in MM and then gets rebooted. But we have had some cases where the NSX component update on the ESXi node fails, and the workload/ TKC VMs running on that ESXi loses network connectivity. To fix this the ESXi node has to be rebooted, and while trying to put the node in MM, the TKC VMs running on it fails to get migrated, and the final option is to force reboot the ESXi and that affects the workload running on it. To avoid this case, the safest option is to choose the upgrade mode as Maintenance, so that the TKCs VMs will get migrated off the ESXi node first before updating the NSX component, and even if the component update fails, we are safe to reboot the node as it is in already in MM. 

• We have also noticed in some cases the ESXi nodes in a WCP cluster fails to enter MM. Following are some common cases:

• Orphaned or inaccessible VMs are one of the main causes. You can follow this article to find those and clean them up.

• I have noticed cases like some VMs (vSphere pods) were present on the ESXi host in poweredoff state. In this case the ESXi was stuck 100% in maintenance mode. You will need to check on those VMs and then delete them if required to proceed further.

• There are cases where some TKC VMs were present on the ESXi host and they fail to get migrated. Check whether these VMs are still present at the Kubernetes layer. If not, delete those VMs!

• Check if there are any TKC nodes still present on the ESXi node. There can be cases where the TKC node or nodes are unable to migrate to other available nodes in the cluster due to resource constraints. Check whether the TKC nodes that are unable to migrate is using guaranteed vmclass. The solution is to find out unused resources/ TKCs in the cluster, check with the owner/ user and then delete it if not being used. Another way is to check with the user and change the guaranteed vmclass to besteffort if possible or temporarily reduce the number of worker nodes if the user agrees to do so.
  
  
• Verify whether any pods are running on the respective ESXi worker node:
kubectl get pods -A -o wide | grep ESXi-FQDN
Safely drain the node.

Hope it was useful. Cheers!

vSphere with Tanzu using NSX-T - Part20 - Safely deleting NotReady nodes from a TKC

In this article we will look at a TKC that is stuck at updating phase which has multiple Kubernetes nodes in NotReady state. 

jtimothy-napp01     gc    updating       2021-07-29T16:59:34Z   v1.20.9+vmware.1-tkg.1.a4cee5b     3     3

❯ gcc kg no | grep NotReady | wc -l
       5

❯ gcc kg no
NAME                                STATUS                        ROLES                  AGE    VERSION
gc-control-plane-2rbsb              Ready                         control-plane,master   410d   v1.20.9+vmware.1
gc-control-plane-5zjn4              Ready                         control-plane,master   123d   v1.20.9+vmware.1
gc-control-plane-9t97w              Ready                         control-plane,master   123d   v1.20.9+vmware.1
gc-control-plane-tnhv9              NotReady                      control-plane,master   63d    v1.20.9+vmware.1
gc-control-plane-tqvnk              NotReady                      control-plane,master   50d    v1.20.9+vmware.1
gc-control-plane-wsclb              NotReady                      <none>                 8d     v1.20.9+vmware.1
gc-control-plane-wt6sx              NotReady                      <none>                 30d    v1.20.9+vmware.1
gc-control-plane-zthnq              NotReady                      control-plane,master   49d    v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   Ready                         <none>                 458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   Ready                         <none>                 456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   Ready                         <none>                 458d   v1.20.9+vmware.1

❯ gcc kg po -A -o wide | grep etcd
kube-system                    etcd-gc-control-plane-2rbsb                         0/1     Running            811        410d    172.31.14.6       gc-control-plane-2rbsb              <none>           <none>
kube-system                    etcd-gc-control-plane-5zjn4                         1/1     Running            1          124d    172.31.14.7       gc-control-plane-5zjn4              <none>           <none>
kube-system                    etcd-gc-control-plane-9t97w                         1/1     Running            1          123d    172.31.14.8       gc-control-plane-9t97w              <none>           <none>

Note: gcc is alias that I am using for KUBECONFIG=gckubeconfig, where gckubeconfig is the kubeconfig file for the TKC under consideration.

Lets verify where etcd pods are running.

❯ gcc kg po -A -o wide | grep etcd
kube-system                    etcd-gc-control-plane-2rbsb                         0/1     Running            811        410d    172.31.14.6       gc-control-plane-2rbsb              <none>           <none>
kube-system                    etcd-gc-control-plane-5zjn4                         1/1     Running            1          124d    172.31.14.7       gc-control-plane-5zjn4              <none>           <none>
kube-system                    etcd-gc-control-plane-9t97w                         1/1     Running            1          123d    172.31.14.8       gc-control-plane-9t97w              <none>           <none>

You can see etcd pods are running on nodes that are in Ready status. So now we can go ahead and safely drain and delete the nodes that are NotReady.

❯ notreadynodes=$(gcc kubectl get nodes | grep NotReady | awk '{print $1;}')

❯ echo $notreadynodes
gc-control-plane-tnhv9
gc-control-plane-tqvnk
gc-control-plane-wsclb
gc-control-plane-wt6sx
gc-control-plane-zthnq

❯ echo "$notreadynodes" | while IFS= read -r line ; do echo $line; gcc kubectl drain $line --ignore-daemonsets; gcc kubectl delete node $line; echo "----"; done

gc-control-plane-tnhv9
node/gc-control-plane-tnhv9 already cordoned
WARNING: ignoring DaemonSet-managed Pods: kube-system/calico-node-nzbgq, kube-system/kube-proxy-2jqqr, vmware-system-csi/vsphere-csi-node-46g6r
node/gc-control-plane-tnhv9 drained
node "gc-control-plane-tnhv9" deleted
----
gc-control-plane-tqvnk
node/gc-control-plane-tqvnk already cordoned
WARNING: ignoring DaemonSet-managed Pods: kube-system/calico-node-45xfc, kube-system/kube-proxy-dxrkr, vmware-system-csi/vsphere-csi-node-wrvlk
node/gc-control-plane-tqvnk drained
node "gc-control-plane-tqvnk" deleted
----
gc-control-plane-wsclb
node/gc-control-plane-wsclb already cordoned
WARNING: ignoring DaemonSet-managed Pods: kube-system/calico-node-5t254, kube-system/kube-proxy-jt2dp, vmware-system-csi/vsphere-csi-node-w2bhf
node/gc-control-plane-wsclb drained
node "gc-control-plane-wsclb" deleted
----
gc-control-plane-wt6sx
node/gc-control-plane-wt6sx already cordoned
WARNING: ignoring DaemonSet-managed Pods: kube-system/calico-node-24pn5, kube-system/kube-proxy-b5vl5, vmware-system-csi/vsphere-csi-node-hfjdw
node/gc-control-plane-wt6sx drained
node "gc-control-plane-wt6sx" deleted
----
gc-control-plane-zthnq
node/gc-control-plane-zthnq already cordoned
WARNING: ignoring DaemonSet-managed Pods: kube-system/calico-node-vp895, kube-system/kube-proxy-8mg8n, vmware-system-csi/vsphere-csi-node-hs22g
node/gc-control-plane-zthnq drained
node "gc-control-plane-zthnq" deleted
----

❯ gcc kg no
NAME                                STATUS   ROLES                  AGE    VERSION
gc-control-plane-2rbsb              Ready    control-plane,master   410d   v1.20.9+vmware.1
gc-control-plane-5zjn4              Ready    control-plane,master   123d   v1.20.9+vmware.1
gc-control-plane-9t97w              Ready    control-plane,master   123d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   Ready    <none>                 458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   Ready    <none>                 456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   Ready    <none>                 458d   v1.20.9+vmware.1
❯
❯ kgtkca | grep jtimothy-napp01
jtimothy-napp01    gc       updating       2021-07-29T16:59:34Z   v1.20.9+vmware.1-tkg.1.a4cee5b     3     3

Now, I waited for few minutes to see whether the reconciliation process will proceed and change the status of the TKC from updating to running. But it was still stuck at updating phase. So I described the TKC.

Conditions:
    Last Transition Time:  2022-12-30T19:47:15Z
    Message:               Rolling 1 replicas with outdated spec (2 replicas up to date)
    Reason:                RollingUpdateInProgress
    Severity:              Warning
    Status:                False
    Type:                  Ready
    Last Transition Time:  2023-01-01T19:19:45Z
    Status:                True
    Type:                  AddonsReady
    Last Transition Time:  2022-12-30T19:47:15Z
    Message:               Rolling 1 replicas with outdated spec (2 replicas up to date)
    Reason:                RollingUpdateInProgress
    Severity:              Warning
    Status:                False
    Type:                  ControlPlaneReady
    Last Transition Time:  2022-07-24T15:53:06Z
    Status:                True
    Type:                  NodePoolsReady
    Last Transition Time:  2022-09-01T09:02:26Z
    Message:               3/3 Control Plane Node(s) healthy. 3/3 Worker Node(s) healthy
    Status:                True
    Type:                  NodesHealthy

Checked vmop logs.

vmware-system-vmop/vmware-system-vmop-controller-manager-85d8986b94-xzd9h[manager]: E0103 08:43:51.449422       1 readiness_worker.go:111] readiness-probe "msg"="readiness probe fails" "error"="dial tcp 172.31.14.6:6443: connect: connection refused" "vmName"="jtimothy-napp01/gc-control-plane-2rbsb" "result"=-1

It says something is wrong with CP node gc-control-plane-2rbsb.

❯ gcc kg po -A -o wide | grep etcd
kube-system                    etcd-gc-control-plane-2rbsb                         0/1     Running            811        410d    172.31.14.6       gc-control-plane-2rbsb              <none>           <none>
kube-system                    etcd-gc-control-plane-5zjn4                         1/1     Running            1          124d    172.31.14.7       gc-control-plane-5zjn4              <none>           <none>
kube-system                    etcd-gc-control-plane-9t97w                         1/1     Running            1          123d    172.31.14.8       gc-control-plane-9t97w              <none>           <none>

You can see etcd pod is not running on first control plane node and is getting continuously restarted. So lets try to drain the CP node gc-control-plane-2rbsb.

❯ gcc k drain gc-control-plane-2rbsb
node/gc-control-plane-2rbsb cordoned
DEPRECATED WARNING: Aborting the drain command in a list of nodes will be deprecated in v1.23.
The new behavior will make the drain command go through all nodes even if one or more nodes failed during the drain.
For now, users can try such experience via: --ignore-errors
error: unable to drain node "gc-control-plane-2rbsb", aborting command...

There are pending nodes to be drained:
 gc-control-plane-2rbsb
cannot delete DaemonSet-managed Pods (use --ignore-daemonsets to ignore): kube-system/calico-node-bdjp7, kube-system/kube-proxy-v9cqf, vmware-system-auth/guest-cluster-auth-svc-n4h2k, vmware-system-csi/vsphere-csi-node-djhpv
cannot delete Pods with local storage (use --delete-emptydir-data to override): vmware-system-csi/vsphere-csi-controller-b4fd6878d-zw5hn

❯ gcc k drain gc-control-plane-2rbsb --ignore-daemonsets --delete-emptydir-data
node/gc-control-plane-2rbsb already cordoned
WARNING: ignoring DaemonSet-managed Pods: kube-system/calico-node-bdjp7, kube-system/kube-proxy-v9cqf, vmware-system-auth/guest-cluster-auth-svc-n4h2k, vmware-system-csi/vsphere-csi-node-djhpv
evicting pod vmware-system-csi/vsphere-csi-controller-b4fd6878d-zw5hn
pod/vsphere-csi-controller-b4fd6878d-zw5hn evicted
node/gc-control-plane-2rbsb evicted

❯ gcc kg no
NAME                                STATUS                     ROLES                  AGE    VERSION
gc-control-plane-2rbsb              Ready,SchedulingDisabled   control-plane,master   410d   v1.20.9+vmware.1
gc-control-plane-5zjn4              Ready                      control-plane,master   123d   v1.20.9+vmware.1
gc-control-plane-9t97w              Ready                      control-plane,master   123d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   Ready                      <none>                 458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   Ready                      <none>                 456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   Ready                      <none>                 458d   v1.20.9+vmware.1

Now lets delete its corresponding machine object.

❯ k delete machine.cluster.x-k8s.io/gc-control-plane-2rbsb -n jtimothy-napp01
machine.cluster.x-k8s.io "gc-control-plane-2rbsb" deleted
❯
❯ kg machine -n jtimothy-napp01
NAME                                CLUSTER   NODENAME                            PROVIDERID                                       PHASE     AGE    VERSION
gc-control-plane-5zjn4              gc        gc-control-plane-5zjn4              vsphere://42015c9c-feed-5eda-6fbe-f0da5d1434ea   Running   124d   v1.20.9+vmware.1
gc-control-plane-9t97w              gc        gc-control-plane-9t97w              vsphere://4201377e-0f46-40b6-e222-9c723c6adb19   Running   123d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   gc        gc-workers-ztr5c-6f4b555879-2v8pl   vsphere://420139b4-83f1-824f-7bd2-ed073a5dcf37   Running   458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   gc        gc-workers-ztr5c-6f4b555879-8qs4p   vsphere://4201d8ac-9cc2-07ac-c352-9f7e812b4367   Running   456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   gc        gc-workers-ztr5c-6f4b555879-r29d5   vsphere://42017666-8cb4-2767-5d0b-1d3dc9219db3   Running   458d   v1.20.9+vmware.1
❯
❯ gcc kg no
NAME                                STATUS   ROLES                  AGE    VERSION
gc-control-plane-5zjn4              Ready    control-plane,master   124d   v1.20.9+vmware.1
gc-control-plane-9t97w              Ready    control-plane,master   123d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   Ready    <none>                 458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   Ready    <none>                 456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   Ready    <none>                 458d   v1.20.9+vmware.1
❯

After few minutes you can see a new machine and the corresponding node got provisioned and the TKC changed from updating to running phase.

❯ kg machine -n jtimothy-napp01
NAME                                CLUSTER   NODENAME                            PROVIDERID                                       PHASE          AGE    VERSION
gc-control-plane-5zjn4              gc        gc-control-plane-5zjn4              vsphere://42015c9c-feed-5eda-6fbe-f0da5d1434ea   Running        124d   v1.20.9+vmware.1
gc-control-plane-9t97w              gc        gc-control-plane-9t97w              vsphere://4201377e-0f46-40b6-e222-9c723c6adb19   Running        123d   v1.20.9+vmware.1
gc-control-plane-dnr66              gc                                                                                             Provisioning   13s    v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   gc        gc-workers-ztr5c-6f4b555879-2v8pl   vsphere://420139b4-83f1-824f-7bd2-ed073a5dcf37   Running        458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   gc        gc-workers-ztr5c-6f4b555879-8qs4p   vsphere://4201d8ac-9cc2-07ac-c352-9f7e812b4367   Running        456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   gc        gc-workers-ztr5c-6f4b555879-r29d5   vsphere://42017666-8cb4-2767-5d0b-1d3dc9219db3   Running        458d   v1.20.9+vmware.1



❯ kg machine -n jtimothy-napp01
NAME                                CLUSTER   NODENAME                            PROVIDERID                                       PHASE     AGE    VERSION
gc-control-plane-5zjn4              gc        gc-control-plane-5zjn4              vsphere://42015c9c-feed-5eda-6fbe-f0da5d1434ea   Running   124d   v1.20.9+vmware.1
gc-control-plane-9t97w              gc        gc-control-plane-9t97w              vsphere://4201377e-0f46-40b6-e222-9c723c6adb19   Running   124d   v1.20.9+vmware.1
gc-control-plane-dnr66              gc        gc-control-plane-dnr66              vsphere://42011228-b156-3338-752a-e7233c9258dd   Running   2m2s   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   gc        gc-workers-ztr5c-6f4b555879-2v8pl   vsphere://420139b4-83f1-824f-7bd2-ed073a5dcf37   Running   458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   gc        gc-workers-ztr5c-6f4b555879-8qs4p   vsphere://4201d8ac-9cc2-07ac-c352-9f7e812b4367   Running   456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   gc        gc-workers-ztr5c-6f4b555879-r29d5   vsphere://42017666-8cb4-2767-5d0b-1d3dc9219db3   Running   458d   v1.20.9+vmware.1
❯
❯ gcc kg no
NAME                                STATUS     ROLES                  AGE    VERSION
gc-control-plane-5zjn4              Ready      control-plane,master   124d   v1.20.9+vmware.1
gc-control-plane-9t97w              Ready      control-plane,master   123d   v1.20.9+vmware.1
gc-control-plane-dnr66              NotReady   control-plane,master   35s    v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   Ready      <none>                 458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   Ready      <none>                 456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   Ready      <none>                 458d   v1.20.9+vmware.1


❯ gcc kg no
NAME                                STATUS   ROLES                  AGE    VERSION
gc-control-plane-5zjn4              Ready    control-plane,master   124d   v1.20.9+vmware.1
gc-control-plane-9t97w              Ready    control-plane,master   123d   v1.20.9+vmware.1
gc-control-plane-dnr66              Ready    control-plane,master   53s    v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-2v8pl   Ready    <none>                 458d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-8qs4p   Ready    <none>                 456d   v1.20.9+vmware.1
gc-workers-ztr5c-6f4b555879-r29d5   Ready    <none>                 458d   v1.20.9+vmware.1

❯ kgtkca | grep jtimothy-napp01
jtimothy-napp01     gc     running      2021-07-29T16:59:34Z   v1.20.9+vmware.1-tkg.1.a4cee5b     3     3

Hope it was useful. Cheers!

vSphere with Tanzu using NSX-T - Part19 - Troubleshooting TKC stuck at creating phase

This article provides basic troubleshooting steps for TKCs (Tanzu Kubernetes Cluster) stuck at creating phase.

Verify status of the TKC

• Use the following commands to verify the TKC status.

kubectl get tkc -n <supervisor_namespace>
kubectl get tkc -n <supervisor_namespace> -o json
kubectl describe tkc <tkc_name> -n <supervisor_namespace>
kubectl get cluster-api -n <supervisor_namespace>
kubectl get vm,machine,wcpmachine -n <supervisor_namespace> 

Cluster health

• Verify health of the supervisor cluster.

❯ kubectl get node
NAME                               STATUS   ROLES                  AGE   VERSION
4201a7b2667b0f3b021efcf7c9d1726b   Ready    control-plane,master   86d   v1.22.6+vmware.wcp.2
4201bead67e21a8813415642267cd54a   Ready    control-plane,master   86d   v1.22.6+vmware.wcp.2
4201e0e8e29b0ddb4b59d3165dd40941   Ready    control-plane,master   86d   v1.22.6+vmware.wcp.2
wxx-08-r02esx13.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx14.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx15.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx16.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx17.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx18.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx19.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx20.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx21.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx22.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx23.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
wxx-08-r02esx24.xxxxxyyyy.com      Ready    agent                  85d   v1.22.6-sph-db56d46
❯
❯ kubectl get --raw '/healthz?verbose'
[+]ping ok
[+]log ok
[+]etcd ok
[+]poststarthook/start-kube-apiserver-admission-initializer ok
[+]poststarthook/generic-apiserver-start-informers ok
[+]poststarthook/priority-and-fairness-config-consumer ok
[+]poststarthook/priority-and-fairness-filter ok
[+]poststarthook/start-apiextensions-informers ok
[+]poststarthook/start-apiextensions-controllers ok
[+]poststarthook/crd-informer-synced ok
[+]poststarthook/bootstrap-controller ok
[+]poststarthook/rbac/bootstrap-roles ok
[+]poststarthook/scheduling/bootstrap-system-priority-classes ok
[+]poststarthook/priority-and-fairness-config-producer ok
[+]poststarthook/start-cluster-authentication-info-controller ok
[+]poststarthook/aggregator-reload-proxy-client-cert ok
[+]poststarthook/start-kube-aggregator-informers ok
[+]poststarthook/apiservice-registration-controller ok
[+]poststarthook/apiservice-status-available-controller ok
[+]poststarthook/kube-apiserver-autoregistration ok
[+]autoregister-completion ok
[+]poststarthook/apiservice-openapi-controller ok
healthz check passed 

Terminating namespaces

• Check for namespaces stuck at terminating phase. If there are any, properly clean them up by removing all child objects. 
• You can use this kubectl get-all plugin to see all resources under a namespace.  Then clean them up properly. Mostly you need to set finalizers of remaining child resources to null. Following is a sample case where 2 PVCs where stuck at terminating and they were cleaned up by setting its finalizers to null.
  

❯ kg ns | grep Terminating
rgettam-gettam                                  Terminating   226d
❯
❯ k get-all -n rgettam-gettam
NAME                                                                                             NAMESPACE       AGE
persistentvolumeclaim/58ef0d27-ba66-4f4e-b4d7-43bd1c4fb833-c8c0c111-e480-4df4-baf8-d140d0237e1d  rgettam-gettam  86d
persistentvolumeclaim/58ef0d27-ba66-4f4e-b4d7-43bd1c4fb833-e5c99b7e-1397-4a9d-b38c-53a25cab6c3f  rgettam-gettam  86d
❯
❯ kg pvc -n rgettam-gettam
NAME                                                                        STATUS        VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS              AGE
58ef0d27-ba66-4f4e-b4d7-43bd1c4fb833-c8c0c111-e480-4df4-baf8-d140d0237e1d   Terminating   pvc-bd4252fb-bfed-4ef3-ab5a-43718f9cbed5   8Gi        RWO            sxx-01-vcxx-wcp-mgmt   86d
58ef0d27-ba66-4f4e-b4d7-43bd1c4fb833-e5c99b7e-1397-4a9d-b38c-53a25cab6c3f   Terminating   pvc-8bc9daa1-21cf-4af2-973e-af28d66a7f5e   30Gi       RWO            sxx-01-vcxx-wcp-mgmt   86d
❯
❯ kg pvc -n rgettam-gettam --no-headers | awk '{print $1}' | xargs -I{} kubectl patch -n rgettam-gettam pvc {} -p '{"metadata":{"finalizers": null}}'

• You can also do kubectl get namespace <namespace> -oyaml and the status section will show if there are resources/ content to be deleted or any finalizers remaining.
  
• Verify vmop-controller pod logs, and restart them if required.
  

IP_BLOCK_EXHAUSTED

• Check CIDR usage of the supervisor cluster.
  

❯ kg clusternetworkinfos
NAME                                                AGE
domain-c1006-06046c54-c9e5-41aa-bc2c-52d72c05bce4   160d
❯
❯ kg clusternetworkinfos domain-c1006-06046c54-c9e5-41aa-bc2c-52d72c05bce4 -o json | jq .usage
{
  "egressCIDRUsage": {
    "allocated": 33,
    "total": 1024
  },
  "ingressCIDRUsage": {
    "allocated": 42,
    "total": 1024
  },
  "subnetCIDRUsage": {
    "allocated": 832,
    "total": 1024
  }
} 

• When the IP blocks of supervisor cluster are exhausted, you will find the following warning when you describe the TKC.

 Conditions:
    Last Transition Time:  2022-10-05T18:34:35Z
    Message:               Cannot realize subnet
    Reason:                ClusterNetworkProvisionFailed
    Severity:              Warning
    Status:                False
    Type:                  Ready 

• Also when you check the namespace, you can see the following ncp error IP_BLOCK_EXHAUSTED.

 ❯ kg ns tsql-integration-test -oyaml
apiVersion: v1
kind: Namespace
metadata:
  annotations:
    calaxxxx.xxxyy.com/xxxrole-created: "1"
    ncp/error: IP_BLOCK_EXHAUSTED
    ncp/router_id: t1_d0a2af0f-8430-4250-9fcf-807a4afe51aa_rtr
    vmware-system-resource-pool: resgroup-307480
    vmware-system-vm-folder: group-v307481
  creationTimestamp: "2022-10-05T17:35:18Z"

Notes:

• If the subnetCIDRUsage IP block is exhausted, you may need to remove some old/ unused namespaces, and that will release some IPs. If that is not possible, you may need to consider adding new subnet.

• After removing the old/ unused namespaces, and even if IPs are available, sometimes the TKCs will be stuck at creating phase! In that case, check the ncp, vmop, and capw controller pods and you may need to restart them. What I observed is usually after restart of ncp pod, vmop-controller pods, and all pods under vmware-system-capw namespaces the VMs will start getting deployed and the TKC creation will progress and complete successfully.

Resource availability

• Check whether there are enough resources available in the cluster.

LAST SEEN  TYPE   REASON       OBJECT                    MESSAGE
3m23s    Warning  UpdateFailure   virtualmachine/magna3-control-plane-9rhl4   The host does not have sufficient CPU resources to satisfy the reservation.
80s     Warning  ReconcileFailure  wcpmachine/magna3-control-plane-s5s9t-p2cxj  vm is not yet powered on: vmware-system-capw-controller-manager/WCPMachine//chakravartha-magna3/magna3/magna3-control-plane-s5s9t-p2cxj 

• Check for resource limits applied to the namespace.

Check whether storage policy is assigned to the namespace

27m         Warning   ReconcileFailure               wcpmachine/gc-pool-0-cv8vz-5snbc          admission webhook "default.validating.virtualmachine.vmoperator.xxxyy.com" denied the request: StorageClass wdc-10-vc21c01-wcp-pod is not assigned to any ResourceQuotas in namespace mpereiramaia-demo2

• In this case, the storage policy wasnt assigned to the ns. I assigned the storage policy wdc-10-vc21c01-wcp-pod to the respective namespace, and the TKC deployment was successful.

Check Content library can sync properly

• Sometimes issues related to CL can cause TKCs to get stuck at creating phase! Check this blog post for more details.

KCP can't remediate

Message:               KCP can't remediate if current replicas are less or equal then 1
Reason:                WaitingForRemediation @ Machine/gc-control-plane-zpssc
Severity:              Warning

• In this case, you can just edit the TKC spec, change the control plane vmclass to a different class and save. Once the deployment is complete and TKC is running, edit the TKC spec again and revert the vmclass that you modified earlier to its original class. This process will re-provision the control plane.
  

TKC VMs waiting for IP

• In this case, take a look at NSXT and check whether all Edge nodes are healthy. If there are mismatch errors, resolve them.
• You may also check ncp pod logs and restart ncp pod if required.

VirtualMachineClassBindingNotFound

Conditions:
    Last Transition Time:  2021-05-05T18:19:10Z
    Message:               1 of 2 completed
    Reason:                VirtualMachineClassBindingNotFound @ Machine/tkc-dev-control-plane-wxd57
    Severity:              Error
    Status:                False
    Message:               0/1 Control Plane Node(s) healthy. 0/2 Worker Node(s) healthy
Events:
  Normal  PhaseChanged  7m22s  vmware-system-tkg/vmware-system-tkg-controller-manager/tanzukubernetescluster-status-controller  cluster changes from creating phase to failed phase

• This happens when the virtualmachineclassbindings are missing and can be resolved by adding all/ required VM Class to the Namespace using the vSphere Client. Following are the steps to add VM Classes to a namespace:

• Log into vCenter web UI
• From Hosts and Clusters > Select the namespace > Summary tab > VM Service tile > Click Manage VM Classes
• Select all required VM Classes and click OK

Verify NSX-T objects

• Issues at the NSX-T side can also cause the TKC to be stuck at creating phase. Following is a sample case and you can see these logs when you describe the TKC:
  

Message: 2 errors occurred:

   * failed to configure DNS for /, Kind= namespace-test-01/gc: unable to reconcile kubeadm ConfigMap's CoreDNS info: unable to retrieve kubeadm Configmap from the guest cluster: configmaps "kubeadm-config" not found
   * failed to configure kube-proxy for /, Kind= namespace-test-01/gc: unable to retrieve kube-proxy daemonset from the guest cluster: daemonsets.apps "kube-proxy" not found

• In this case, these were some issues with the virtual servers in loadbalancer. Some stale entries of virtual servers were still present and their IP didn't get removed properly and it was causing some intermittent connectivity issues to some of the other services of type loadbalancer. And, new TKC deployment within that affected namespace also gets stuck due to this. In our case we deleted the affected namespace, and recreated it, that cleaned up all those virtual server state entries and the load balancer, and new TKC deployments were successful. So it will be worth to check on the health and staus of NSX-T objects in case you have TKC deployment issues.
  

Check for broken TKCs in the cluster

• Sometimes the TKC deployments are very slow and takes more than 30 minutes. In this case, you may notice that the first control plane VM will get deployed in like 30-45 minutes after the TKC creation has started. Look for vmop controller logs. Following is sample log:

❯ kail -n vmware-system-vmop
vmware-system-vmop/vmware-system-vmop-controller-manager-55459cb46b-2psrk[manager]: E1027 11:49:44.725620       1 readiness_worker.go:111] readiness-probe "msg"="readiness probe fails" "error"="dial tcp 172.29.9.212:6443: connect: connection refused" "vmName"="ciroscosta-cartographer/kontinue-control-plane-svlk4" "result"=-1

vmware-system-vmop/vmware-system-vmop-controller-manager-55459cb46b-2psrk[manager]: E1027 11:49:49.888653       1 readiness_worker.go:111] readiness-probe "msg"="readiness probe fails" "error"="dial tcp 172.29.2.66:6443: connect: connection refused" "vmName"="whaozhe-platform/gc-control-plane-mf4p5" "result"=-1

• In the above case, two of the TKCs were broken/ stuck at updating phase and we were unable to connect to its control plane.

ciroscosta-cartographer    kontinue    updating       2021-10-29T18:47:46Z   v1.20.9+vmware.1-tkg.1.a4cee5b    1     2
whaozhe-platform           gc          updating       2022-01-27T03:59:31Z   v1.20.12+vmware.1-tkg.1.b9a42f3   1     10

• After removing the namespaces with broken TKCs, new deployments were completing succesfully. 
  

Restart system pods

• Sometimes restart of some of the system controller pods resoves the issue. I usually delete all the pods of the following namespaces and they will get restarted in a few seconds.

k delete pod --all --namespace=vmware-system-vmop
k delete pod --all --namespace=vmware-system-capw
k delete pod --all --namespace=vmware-system-tkg
k delete pod --all --namespace=vmware-system-csi
k delete pod --all --namespace=vmware-system-nsx

Hope this was useful. Cheers!