sandervanvugt / cka Goto Github PK

https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64/repodata/repomd.xml: [Errno -1] repomd.xml signature could not be verified for kubernetes

Hello,
I was following this CKA cource in safari online. But I could see CKA directory do not have the yaml files to follow the lesson6 managing storage.

Hi Sander,

I am able to install the ingress controller. able to deploy the nginxsvc pod, able to create nginxsvc service without any issues. However, while creating ingress i am getting below error:

error: failed to create ingress: Internal error occurred: failed calling webhook "validate.nginx.ingress.kubernetes.io": failed to call webhook: Post "https://ingress-nginx-controller-admission.ingress-nginx.svc:443/networking/v1/ingresses?timeout=10s": context deadline exceeded

Can you suggest what could be the issue?

Regards,
Love Masta

The legacy package repositories (apt.kubernetes.io and yum.kubernetes.io) have been deprecated and frozen starting from September 13, 2023. Using the new package repositories hosted at pkgs.k8s.io is strongly recommended and required in order to install Kubernetes versions released after September 13, 2023. The deprecated legacy repositories, and their contents, might be removed at any time in the future and without a further notice period. The new package repositories provide downloads for Kubernetes versions starting with v1.24.0.

Update setup-kubetools.sh script

replace lines:

sudo apt-get update && sudo apt-get install -y apt-transport-https curl
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF

with

sudo apt-get update && sudo apt-get install -y apt-transport-https curl
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.28/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.28/deb/ /" | sudo tee /etc/apt/sources.list.d/kubernetes.list

Hi Sander,

I was highly motivated to learn k8s from your course. I have 3 Ubuntu 22.04 instances running in AWS EC2 out of which on one of them I followed the steps mentioned in your course to set as control plane.

I used both the .sh files to install container runtime and Kube tools. After that I used sudo kubeadm init as mentioned in the video. Then performed steps to get cluster context. After that I simply did kubectl create -f cka/calico.yaml but my calico container is in crashloopbackoff state.

can you suggest if there are any changes I need to know to make it work ?

initContainers of init-pod pod (lab7-1.yaml) may not run at all because it depends on the latest busybox image.
I found the behavior change is in busybox:1.29 to busybox:1.32 (latest) see Nslookup does not work in latest busybox image #48.

[root@master01 learn]# kubectl run --attach busybox --rm --image=busybox:latest --restart=Never -- \
> sh -c "sleep 4 && nslookup kubernetes"
If you don't see a command prompt, try pressing enter.
Server:         10.96.0.10
Address:        10.96.0.10:53

** server can't find kubernetes.default.svc.cluster.local: NXDOMAIN

*** Can't find kubernetes.svc.cluster.local: No answer
*** Can't find kubernetes.cluster.local: No answer
*** Can't find kubernetes.default.svc.cluster.local: No answer
*** Can't find kubernetes.svc.cluster.local: No answer
*** Can't find kubernetes.cluster.local: No answer

pod "busybox" deleted
pod default/busybox terminated (Error)

busybox:1.28 is working fine.

[root@master01 learn]# kubectl run --attach busybox --rm --image=busybox:1.28 --restart=Never -- \
> sh -c "sleep 4 && nslookup kubernetes"
If you don't see a command prompt, try pressing enter.
Server:    10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: 10.96.0.1 kubernetes.default.svc.cluster.local
pod "busybox" deleted
[root@master01 learn]#

So, a simple solution to solve this problem is to use busybox:1.28 as in this snippet.

[root@master01 learn]# cat lab7-1.yaml
apiVersion: v1
kind: Pod
metadata:
  name: init-pod
  labels:
    app: initapp
spec:
  containers:
  - name: main-container
    image: busybox
    command: ['sh', '-c', 'echo main app running && sleep 3600']
  initContainers:
  - name: init-myservice
    image: busybox:1.28
    command: ['sh', '-c', 'until nslookup myservice; do echo waiting for myservice; sleep 2; done']
  - name: init-mydb
    image: busybox:1.28
    command: ['sh', '-c', 'until nslookup mydb; do echo waiting for mydb; sleep 2; done']
[root@master01 learn]#

Another useful tool to troubleshoot DNS problem in kubernetes in dnsutils.

I don't see well enough to read the yaml files in the videos, because there isn't enough contrast between the light text and the bright background. Please add all of the yaml files to the repo. Please consider using a dark theme in the future videos.

Need help with the following after running vagrant up. PLEASE.
START ERROR*****
control: 2023-02-22 15:58:40 (1.60 MB/s) - ‘go1.13.linux-amd64.tar.gz’ saved [120050424/120050424]
control:
control: + tar -C /usr/local -xzf go1.13.linux-amd64.tar.gz
control: + git clone https://github.com/Mirantis/cri-dockerd.git
control: Cloning into 'cri-dockerd'...
control: + cd cri-dockerd/src
control: /tmp/vagrant-shell: line 90: cd: cri-dockerd/src: No such file or directory
control: + cd ..
control: + install -o root -g root -m 0755 bin/cri-dockerd /usr/local/bin/cri-dockerd
control: install: cannot stat ‘bin/cri-dockerd’: No such file or directory
The SSH command responded with a non-zero exit status. Vagrant
assumes that this means the command failed. The output for this command
should be in the log above. Please read the output to determine what
went wrong.
END ERROR*****

/home/vagrant/cri-dockerd exists but /home/vagrant/cri-dockerd/src doesn't.

Just a quick suggestion, how about categorizing all these YAML files in the respective lessons as per your CKA course on O'Reilly, e.g. lesson_10/rolebind.yaml.
If this is okay with you, I could go ahead and do a PR.

Otherwise, great course and thanks for doing this!

I am getting an error in the setup stage (preflight check) no route to host. After running it with --v to check the stacktrace, I see the message saying: [discovery] Failed to request cluster-info, will try again: Get

• I used kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.25.0/manifests/calico.yaml on the master node for calico installation.

The kubeadm version and the dockerd version are giving troubles to join the nodes