Cloud Devops Automation

  Issue:-   The issue was occuring when i tried to run the metric server inside the kubernetes. And after deploying tried to list the cpu utilization based on the nodes [centos@k8smaster volumes]$ kubectl top nodes Error:-  Error from server (ServiceUnavailable): the server is currently unable to handle the request (get nodes.metrics.k8s.io) Resolution:- This can easily be resolved by editing the deployment yaml files and adding the hostNetwork: true after the dnsPolicy: ClusterFirst kubectl edit deployments.apps -n kube-system metrics-server hostNetwork: ture

  Issue:-   The issue was occuring when i tried to generate the certificate using the following command. sudo openssl genrsa -des3 -out server.key 1024 Error:-  UI_set_result:result too small:ui_lib.c:869:You must type in 4 to 1024 characters Cause:- Leave off the -des3 flag, which is an instruction to the openssl to encrypt the server.keynew which is not a new key at all - its exactly the same key as server.key only with the passphrase changed or removed. Resolution:- so i updated the command as  sudo openssl genrsa -out server.key 1024 which worked fine.

  Issue:-   Issue occured when i tried to create the reverse proxy in the nginx upstream dashboard { server 172.31.4.205:30545; } server { listen 443; listen [::]:443; ssl_certificate /etc/nginx/ssl/server.crt; ssl_certificate_key /etc/nginx/ssl/server.key; location / { proxy_set_header X-Forwarded-Host $host:$server_port; proxy_set_header X-Forwarded-Server $host; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_pass https://dashboard; } } Error:-  ssl received a record that exceeded the maximum permissible length centos

Issue:-   The issue occured when i was trying to use the upstream to proxypass i.e. use the nginx as reverse proxy for exposing the kubernetes application. Error:-  unknown directive "upstream" in /etc/nginx/nginx.conf:1 configuration file /etc/nginx/nginx.conf test failed Cause:- In Nginx upstream directive is only valid in the http contex. Resolution:- So instead of making the changes in the nginx.conf try to use this in the default.conf. Also I preferred to proxy the request directly in the default.conf which actually got the rid of the upstream although when i tested upstream also worked fine. So i made the change under /etc/nginx/sites-enabled/default.conf which is soft link to  /etc/nginx/sites-available/default.conf

  Issue:-   Issue occured when i tried to deployed the deployment yaml file on the kubernetes. kind: Deployment metadata: name: jenkins namespace: jenkins template: metadata: labels: app: jenkins spec: volumes: - name: jenkins-home persistentVolumeClaim: claimName: pvc-nfs-pv1 containers: - name: jenkins image: jenkins/jenkins:lts lifecycle: postStart: exec: command: ["/bin/sh", "-c", "/var/jenkins_home/ip-update.sh"] env: - name: JAVA_OPTS value: -Djenkins.install.runSetupWizard=false ports: - name: http-port containerPort: 8080 - name: jnlp-port containerPort: 50000 volumeMounts: - name: jenkins-home mountPath: /var/jenkins_home Error:-  ValidationError(Deployment.spec): missing required field "selector" in io.k8s.api.apps....