I contact you because I passed the CKA exam twice unfortunately I failed.
For the first I had a score of 40% and the second 57%.
I need your help on three issues that prevent me from passing the new version of the CKA certification.
on the questions on the cluster upgrade and the restoration of ETCD
The operations do not work because the files and admin.conf, kubelet.conf, config.yaml as well as etcd.yaml are not present on the default directory and I cannot find these files. As a result, I did not succeed in these two tasks.
and on the third question it is asked to create a pod which contains a container with multiple images. I donât know how to do it.
I would like to have your help in order to pass this certification.
Look for âconfig in the file. View the file mentioned in âconfig and look for âstaticPodPathâ. The âetcd.yamlâ file should be present here.
W.r.t CKA exam the etcd is installed on the edge node and the question is to take etcd backup and restore on edge node only. Keep in mind when attempting this question.
Some tips to check etcd server on edge node:
Step 1: check the etcd server status:
cloud@edge-node:~$ systemctl status etcd
â etcd.service - etcd
Loaded: loaded (/etc/systemd/system/etcd.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2021-01-29 21:58:40 CST; 2 days ago
Docs: CoreOS ¡ GitHub
Main PID: 1299767 (etcd)
Tasks: 10 (limit: 4615)
Memory: 8.3M
CGroup: /system.slice/etcd.service
ââ1299767 /usr/bin/etcd --name master-1 --cert-file=/etc/etcd/etcd.crt --key-file=/etc/etcd/etcd.key --peer-cert-file=/etc/etcd/etcd.cr>
Step 3: You will see certificate and data dir paths on edge node. Keep in mind the certificate paths will be provided in question itself.
Step 4: backup and restore commands from the course should work on edge node.
Step 5: When you attempt restore to different --data-dir make sure to change the folder owner permissions:
For example if the new data-dir is /var/lib/etcd-from-back-up issue the below command to change the permissions
chown +R etcd.etcd /var/lib/etcd-from-back-up
thank you very much, it is very clear.
i hope to succeed in this task
please , a last question.
for the cluster upgrade is done on the master node or edge node ?
âdata-dir is restored on the student node (base node), do we need to copy this directory on the master node as etcd service is running on the master node and not on the base node. Also, what about cluster token details?
Was just thinking: The etcd service/process is running on the master node right? So, how the process gets the restored data details? is NFS configured b/w student node & master node. Please clarify. Thanks.
I also think that on the exam it will be necessary to copy the directory from the base node to the master node or to launch the restoration on the master. so the directory is on the master.
at the same time I also doubt that the etcd is running on the base node.
Ramalrg , are you sure that the etcd is runind as a service on the base node ?
Hmmm. The question clearly says that etcd is running at 127.0.0.1:2379. Also systemctl status etcd on base node reports it is active and running. The same command on master mode reports no etcd is running. So it is evident that etcd is running on base node. I couldnât get a chance to check NFS between master and base node due to time limitations in exam.
The steps provided in my previous post were tried on my 3 node cluster.
I know this is little bit confusing but this is the solution I have got it from various blogs, forums and after tried out in our local cluster.
@ramalrg During etcd restore in edge/worker node, after the restore command is executed, do we need to update the etcd.yaml static pod file to update the new data-dir values? If yes, where can we find this yaml file in the worker node. Or it is not needed at all as it is running as a service?
Thank you so much for your detailed explanation. This helped me clear my doubt as well ⌠I was able to upgrade the cluster but was facing issues in restoring etcd. As per the course, I restored the etcd backup in another dir but then I couldnât find the manifest path and YAML file. Then I tried to look for the kubelet service so that I can find out the manifest folder path if itâs different on this student node. But to my surprise, there was no kubelet service running. I mean service kubelet status or systemctl status kubelet didnât return any output therefore I was unable to find the config file to look for a manifest folder. Little did I know that the etcd was in fact running as a service.
But do you think it was possible that there was no kubelet service running on that node?
guy as anybody can explain the above question with sample Master Node or Student Node, in the mentioned steps and as well how to edit the Data dir in the Service file and so on, appreciate your prompt respond, as far i know the ETCD will be running on the Master Node so should we take the backup on Master and then restore it on Student/Edge Node, please more clarification to the steps will be highly appreciated
For example, if i restored the backup to /var/lib/etcd/backup ,
in this case, instead of editing the etcd config â data-dir= ,
can I copy the restored file to /var/lib/etcd/ , does this works ?
<<For example if the new data-dir is /var/lib/etcd-from-back-up issue the below command to change the permissions
chown +R etcd.etcd /var/lib/etcd-from-back-up>>
is this âetcd.etcdâ is username and group of etcdctl ? , how can we find it.
This is million dollars answer. I did a very complicate solution in this task which accidently broke the etcd of ok8s cluster that is NOT used in this task.
When I started the task that using the ok8s cluster, I got âthe connection to the server xx.xx.xx.xx 6443 was refused - did you specify the right host or portâ. Therefore, I cannot do it, lost 7%.
And then I found another cluster mk8s totally down, âkubectl get nodeâ returns nothing. the cluster is shared with the ETCD task as well. I lost another 7%
I totally lost 21% because this failed task. I donât think it is fair, because other two tasks shouldnât be impacted.