All-Things-Docker-and-Kubernetes

Practice Test: CKA

Some of the scenario questions here are based on Kodekloud’s CKA course labs.

Logging and Monitoring

Note

CKAD and CKA can have similar scenario questions. It is recommended to go through the CKAD practice tests.

Shortcuts

First run the two commands below for shortcuts.

export do="--dry-run=client -o yaml" 
export now="--force --grace-period=0" 

Questions

  1. Deploy metrics-server to monitor the PODs and Nodes.

    Answer ```bash controlplane ~ ➜ k get po NAME READY STATUS RESTARTS AGE elephant 1/1 Running 0 10s lion 1/1 Running 0 10s rabbit 1/1 Running 0 10s controlplane ~ ➜ git clone https://github.com/kodekloudhub/kubernetes-metrics-server.git Cloning into 'kubernetes-metrics-server'... remote: Enumerating objects: 31, done. remote: Counting objects: 100% (19/19), done. remote: Compressing objects: 100% (19/19), done. remote: Total 31 (delta 8), reused 0 (delta 0), pack-reused 12 Unpacking objects: 100% (31/31), 8.06 KiB | 1.34 MiB/s, done. controlplane ~ ➜ ls -l total 4 drwxr-xr-x 3 root root 4096 Dec 29 03:44 kubernetes-metrics-server -rw-rw-rw- 1 root root 0 Dec 13 05:39 sample.yaml controlplane ~ ✖ k apply -f kubernetes-metrics-server/ clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created serviceaccount/metrics-server created deployment.apps/metrics-server created service/metrics-server created clusterrole.rbac.authorization.k8s.io/system:metrics-server created clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created ``` Start monitoring the nodes. ```bash controlplane ~ ➜ k top node NAME CPU(cores) CPU% MEMORY(bytes) MEMORY% controlplane 241m 0% 1159Mi 0% node01 24m 0% 300Mi 0% ```

    </br>

  2. Identify the POD that consumes the most Memory(bytes) in default namespace.

    Answer ```bash controlplane ~ ➜ k get po NAME READY STATUS RESTARTS AGE elephant 1/1 Running 0 4m33s lion 1/1 Running 0 4m33s rabbit 1/1 Running 0 4m33s controlplane ~ ➜ k top pod NAME CPU(cores) MEMORY(bytes) elephant 15m 31Mi lion 1m 18Mi rabbit 107m 252Mi ```

    </br>

  3. A user - USER5 - has expressed concerns accessing the application. Identify the cause of the issue.

     controlplane ~ ➜  k get po
     NAME       READY   STATUS    RESTARTS   AGE
     webapp-1   1/1     Running   0          108s 
    
    Answer ```bash controlplane ~ ✖ k logs webapp-1 | grep WARNING [2023-12-29 08:49:33,717] WARNING in event-simulator: USER5 Failed to Login as the account is locked due to MANY FAILED ATTEMPTS. [2023-12-29 08:49:36,719] WARNING in event-simulator: USER7 Order failed as the item is OUT OF STOCK. [2023-12-29 08:49:38,722] WARNING in event-simulator: USER5 Failed to Login as the account is locked due to MANY FAILED ATTEMPTS. [2023-12-29 08:49:43,728] WARNING in event-simulator: USER5 Failed to Login as the account is locked due to MANY FAILED ATTEMPTS. ```

    </br>

  4. A user is reporting issues while trying to purchase an item. Identify the user and the cause of the issue. Inspect the logs of the webapp-2 in the POD

     controlplane ~ ➜  k get po 
     NAME       READY   STATUS    RESTARTS   AGE
     webapp-1   1/1     Running   0          2m53s
     webapp-2   2/2     Running   0          17s 
    
    Answer ```bash controlplane ~ ➜ k logs webapp-2 | grep WARNING Defaulted container "simple-webapp" out of: simple-webapp, db [2023-12-29 08:52:05,219] WARNING in event-simulator: USER5 Failed to Login as the account is locked due to MANY FAILED ATTEMPTS. [2023-12-29 08:52:08,221] WARNING in event-simulator: USER30 Order failed as the item is OUT OF STOCK. [2023-12-29 08:52:10,224] WARNING in event-simulator: USER5 Failed to Login as the account is locked due to MANY FAILED ATTEMPTS. [2023-12-29 08:52:15,228] WARNING in event-simulator: USER5 Failed to Login as the account is locked due to MANY FAILED ATTEMPTS. [2023-12-29 08:52:16,229] WARNING in event-simulator: USER30 Order failed as the item is OUT OF STOCK. ```

    </br>

Back to the top