Skip to main content

Question 20 | Update Kubernetes Version and join cluster

 

Your coworker said node cluster3-worker2 is running an older Kubernetes version and is not even part of the cluster. Update Kubernetes on that node to the exact version that's running on cluster3-master1. Then add this node to the cluster. Use kubeadm for this.

 

Answer:
Upgrade Kubernetes to cluster3-master1 version

Search in the docs for kubeadm upgrade: https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/kubeadm-upgrade

Master node seems to be running Kubernetes 1.22.1 and cluster3-worker2 is not yet part of the cluster.

Here kubeadm is already installed in the wanted version, so we can run:

This is usually the proper command to upgrade a node. But this error means that this node was never even initialised, so nothing to update here. This will be done later using kubeadm join. For now we can continue with kubelet and kubectl:

Now we're up to date with kubeadm, kubectl and kubelet. Restart the kubelet:

We can ignore the errors and move into next step to generate the join command.

 

Add cluster3-master2 to cluster

First we log into the master1 and generate a new TLS bootstrap token, also printing out the join command:

We see the expiration of 23h for our token, we could adjust this by passing the ttl argument.

Next we connect again to worker2 and simply execute the join command:

If you have troubles with kubeadm join you might need to run kubeadm reset.

This looks great though for us. Finally we head back to the main terminal and check the node status:

Give it a bit of time till the node is ready.

We see cluster3-worker2 is now available and up to date.

Labels:

Comments

Post a Comment

https://gengwg.blogspot.com/

Popular posts from this blog

CKA Simulator Kubernetes 1.22

  https://killer.sh Pre Setup Once you've gained access to your terminal it might be wise to spend ~1 minute to setup your environment. You could set these: alias k = kubectl                         # will already be pre-configured export do = "--dry-run=client -o yaml"     # k get pod x $do export now = "--force --grace-period 0"   # k delete pod x $now Vim To make vim use 2 spaces for a tab edit ~/.vimrc to contain: set tabstop=2 set expandtab set shiftwidth=2 More setup suggestions are in the tips section .     Question 1 | Contexts Task weight: 1%   You have access to multiple clusters from your main terminal through kubectl contexts. Write all those context names into /opt/course/1/contexts . Next write a command to display the current context into /opt/course/1/context_default_kubectl.sh , the command should use kubectl . Finally write a second command doing the same thing into ...
Post a Comment
Read more

OWASP Top 10 Threats and Mitigations Exam - Single Select

Last updated 4 Aug 11 Course Title: OWASP Top 10 Threats and Mitigation Exam Questions - Single Select 1) Which of the following consequences is most likely to occur due to an injection attack? Spoofing Cross-site request forgery Denial of service   Correct Insecure direct object references 2) Your application is created using a language that does not support a clear distinction between code and data. Which vulnerability is most likely to occur in your application? Injection   Correct Insecure direct object references Failure to restrict URL access Insufficient transport layer protection 3) Which of the following scenarios is most likely to cause an injection attack? Unvalidated input is embedded in an instruction stream.   Correct Unvalidated input can be distinguished from valid instructions. A Web application does not validate a client’s access to a resource. A Web action performs an operation on behalf of the user without checkin...
2 comments
Read more