Exam CKA topic 1 question 13 discussion

This is an example that will work for this question for me: vi sd1.yaml apiVersion: v1 kind: Pod metadata: name: big-corp-app spec: containers: - name: count image: busybox:1.28 args: - /bin/sh - -c - > i=0; while true; do echo "$i: $(date)" >> /var/log/big-corp-app.log; i=$((i+1)); sleep 1; done volumeMounts: - name: varlog mountPath: /var/log - name: sidecar image: busybox args: [/bin/sh, -c, 'tail -n+1 -F /var/log/big-corp-app.log'] volumeMounts: - name: varlog mountPath: /var/log volumes: - name: varlog emptyDir: {} --- kubectl apply -f sd1.yaml kubectl logs big-corp-app -c sidecar

solution : https://kubernetes.io/docs/concepts/cluster-administration/logging/#sidecar-container-with-logging-agent

killer_sh_lab practice only part 2: k apply -f big-corp-app.yml k logs big-corp-app -c sidecar k exec -it big-corp-app -c=count -- cat /var/log/big-corp-app.log k exec -it big-corp-app -c=sidecar -- cat /var/log/big-corp-app.log # admin/logging/two-files-counter-pod-agent-sidecar.yaml # Remove the extra volumeMounts / volume

killer_sh_lab practice only part 1: vi big-corp-app.yml apiVersion: v1 kind: Pod metadata: name: big-corp-app spec: containers: - name: count image: busybox:1.28 args: - /bin/sh - -c - > i=0; while true; do echo "$i: $(date)" >> /var/log/1.log; echo "$(date) INFO $i" >> /var/log/big-corp-app.log; i=$((i+1)); sleep 1; done volumeMounts: - name: varlog mountPath: /var/log - name: sidecar image: busybox:1.28 args: [/bin/sh, -c, 'tail -n+1 -F /var/log/big-corp-app.log'] volumeMounts: - name: varlog mountPath: /var/log volumes: - name: varlog emptyDir: {}

apiVersion: v1 kind: Pod metadata: name: counter spec: containers: - name: count image: busybox:1.28 args: - [/bin/sh, -c, 'tail -n+1 -f /var/log/bit-corp-app.log'] volumeMounts: - name: varlog mountPath: /var/log volumes: - name: varlog emptyDir: {}

This is an exam question or not answers are not accuarte

apiVersion: v1 kind: Pod metadata: creationTimestamp: null labels: run: nginx name: nginx spec: containers: - image: nginx name: nginx - image: busybox name: sidecar command: ["/bin/sh"] args: [ "-c", "tail -n+1 -f /var/log/big-corp-app.log" ] volumeMounts: - name: log mountPath: /var/log volumes: - name: log hostPath: path: /var/log type: Directory

create a bigcorp.yaml apiVersion: v1 kind: Pod metadata: name: big-corp-app spec: containers: - name: count image: busybox args: - /bin/sh - -c - > i=0; while true; do echo "$i: $(date)" >> /var/log/ big-corp-app.log i=$((i+1)); sleep 1; done volumeMounts: - name: varlog mountPath: /var/log - name: sidecar image: busybox args: [/bin/sh, -c, 'tail -n+1 -f /var/log/big-corp-app.log'] volumeMounts: - name: varlog mountPath: /var/log kubectl create -f bigcorp.yaml

i had this question but there was an issue with it not finding the file from the script in the first container

vi sidecar.yaml apiVersion: v1 kind: Pod metadata: name: big-corp-app spec: containers: - name: count image: busybox:1.28 args: - /bin/sh - -c - > i=0; while true; do echo "$i: $(date)" >> /var/log/1.log; echo "$(date) INFO $i" >> /var/log/2.log; i=$((i+1)); sleep 1; done volumeMounts: - name: varlog mountPath: /var/log - name: sidecar image: busybox:1.28 args: [/bin/sh, -c, 'tail -n+1 -F /var/log/big-corp-app.log'] volumeMounts: - name: varlog mountPath: /var/log volumes: - name: varlog emptyDir: {} k create -f sidecar.yaml k get pod NAME READY STATUS RESTARTS AGE big-corp-app 2/2 Running 0 9s

apiVersion: v1 kind: Pod metadata: name: big spec: containers: - name: big image: nginx volumeMounts: - name: varlog mountPath: /var/log/nginx/ - name: sidecar image: busybox:1.28 args: [/bin/sh, -c, 'tail -n+1 -F /var/log/nginx/access.log'] volumeMounts: - name: varlog mountPath: /var/log/nginx/ volumes: - name: varlog emptyDir: {} https://kubernetes.io/docs/concepts/cluster-administration/logging/#sidecar-container-with-logging-agent

Are we to describe and write the existing configuration of the deployment to a file, delete the deployment, then recreate it?

Who started the " include env in sidecar container" thing? What are the reasons to use ENV from main container in the sidecar container? ENV variable from container 1 is not visible in container 2?

I failed this question in my exam but I cannot tell the reason. The sidecar container was not running and pod was in Crashloopback. I used "args" when defining the sidecar container like: args: - /bin/sh - -c - tail n+1 .... and I thought "command" should have been used. But in the busybox image there is CMD ["sh"] so in my case "args" would work. Tested also like this and the pod is running. I cannot tell at this moment what I did wrong. Any ideas? controlplane ~ ➜ k get pods mypod -o yaml apiVersion: v1 kind: Pod metadata: creationTimestamp: "2023-07-13T12:04:25Z" labels: run: mypod name: mypod namespace: default resourceVersion: "1029" uid: c135577f-fad5-4127-a3a2-1ae0cb074e83 spec: containers: - args: - /bin/sh - -c - echo "this is a test"; sleep 3600 image: busybox

Is it correct, if exiting yaml file has -env defined, I don't add a container under env and also do not include env in sidecar container, just adding sidecar container under spec like this? Spec : name: sidecar image: busybox command: ["/bin/sh", "-c", "kkkkkkmm"] volumeMounts: - name: log-volume mountPath: /var/log volumes: - name: log-volume emptyDir: {}

Why its required to have env variable?

don't forget to also define outside the container context: volumes: - name: varlog emptyDir: {}