docs: add Kubernetes CKS study notes

2026-08-04 23:18:45 +02:00
parent a6ee7a2b07
commit 91a1849009
57 changed files with 8313 additions and 0 deletions
--- a/exams/exam-2.md
+++ b/exams/exam-2.md
@@ -0,0 +1,114 @@
+```bash
+
+# storageclass
+apiVersion: storage.k8s.io/v1
+kind: StorageClass
+metadata:
+  name: local-sc
+  annotations:
+    storageclass.kubernetes.io/is-default-class: "true"
+provisioner: kubernetes.io/no-provisioner
+reclaimPolicy: Retain # default value is Delete
+volumeBindingMode: WaitForFirstConsumer
+
+# -------------
+
+# multipod deployment
+
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  labels:
+    app: logging-deployment
+  name: logging-deployment
+  namespace: logging-ns
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: logging-deployment
+  strategy: {}
+  template:
+    metadata:
+      labels:
+        app: logging-deployment
+    spec:
+      containers:
+      - command: ["/bin/sh", "-c"]
+        args:
+        - |
+          mkdir -p /var/log/app
+          while true; do
+            echo "Log entry" >> /var/log/app/app.log
+            sleep 5
+          done
+        image: busybox
+        name: busybox
+        volumeMounts:
+        - name: log-vol
+          mountPath: /var/log/app
+      - name: log-agent
+        image: busybox
+        command: ["/bin/sh", "-c"]
+        args:
+        - |
+          touch /var/log/app/app.log
+          tail -f /var/log/app/app.log
+        volumeMounts:
+        - name: log-vol
+          mountPath: /var/log/app
+      volumes:
+      - name: log-vol
+        emptyDir: {}
+
+# -----------
+
+kubectl create ingress webapp-ingress -n ingress-ns --rule="kodekloud-ingress.app/*=webapp-svc:80" --class=nginx -o yaml --dry-run > ingress.yaml
+
+# --------
+
+# create deployment, upgrade image
+kubectl create deployment nginx-deploy --image=nginx:1.16 --replicas=1
+kubectl set image deployment/nginx-deploy nginx=nginx:1.17
+
+# --------
+
+cat csr.yaml 
+apiVersion: certificates.k8s.io/v1
+kind: CertificateSigningRequest
+metadata:
+  name: john-developer # example
+spec:
+  # This is an encoded CSR. Change this to the base64-encoded contents of myuser.csr
+  request: 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
+  signerName: kubernetes.io/kube-apiserver-client
+  expirationSeconds: 86400 # one day
+  usages:
+  - client auth
+
+kubectl certificate approve john
+kubectl certificate approve john-developer
+
+kubectl create role developer --verb=create,list,get,update,delete --resource=pods -n development
+kubectl create rolebinding developer --role developer -n  development --user=john
+
+
+# ---------
+
+kubectl run nginx-resolver --image=nginx
+kubectl expose pod nginx-resolver --port=80 --name=nginx-resolver-service
+
+k run test-dns --image=busybox:1.28 --rm -it --restart=Never \
+  -- nslookup nginx-resolver-service > /root/CKA/nginx.svc
+
+k run test-dns --image=busybox:1.28 --rm -it --restart=Never -- nslookup 172-17-1-15.default.pod.cluster.local > /root/CKA/nginx.pod
+
+# -----
+# nginx-critical
+
+k run nginx-critical --image=nginx -o yaml --dry-run > /etc/kubernetes/manifests/nginx-critical.yaml
+
+# ------
+# HPA
+kubectl autoscale deployment backend-deployment --min=3 --max=15 --memory=65% --name backend-hpa -n backend
+