https://quicktasks.ismael.casimpan.com/tags/kubernetes/Recent content in kubernetes on IT QuicktasksHugo -- gohugo.ioCopyright © 2018–2022, Ismael Casimpan Jr.; All Rights ReservedWed, 19 Aug 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/shell-into-kubernetes-pod/Wed, 19 Aug 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/shell-into-kubernetes-pod/ Syntax: 1kubectl exec --stdin --tty <pod_name> -- /bin/bash Example, with the following pods 1me@example:~$ kubectl get pod 2NAME READY STATUS RESTARTS AGE 3cert-manager-cainjector-68c88cc858-c2rhx 1/1 Running 0 109m 4cert-manager-d76d644df-pgqn9 1/1 Running 0 109m 5cert-manager-webhook-6dd68c6fbc-rzcln 1/1 Running 0 109m 6my-first-vanilla-drupal-6f6dd66b94-xldj7 1/1 Running 0 108m 7my-first-vanilla-drupal-mariadb-0 1/1 Running 0 108m 8traffic-cop-nginx-ingress-controller-5d685cfd59-pjfdg 1/1 Running 0 144m 9traffic-cop-nginx-ingress-default-backend-55f6bcb48-brg6b 1/1 Running 0 144m Run this to go to the drupal pod my-first-vanilla-drupal-6f6dd66b94-xldj7 1kubectl exec --stdin --tty my-first-vanilla-drupal-6f6dd66b94-xldj7 -- /bin/bash It's just like any docker container or linux machine when you're in:https://quicktasks.ismael.casimpan.com/post/adding-helm-repo/Sun, 28 Jun 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/adding-helm-repo/ A Helm Repo that's in https://github.com/codecentric/helm-charts has a corresponding repo URL. Add it as follows: 1user@example:~$ helm repo add codecentric https://codecentric.github.io/helm-charts 2"codecentric" has been added to your repositorieshttps://quicktasks.ismael.casimpan.com/post/change-default-cluster-in-kubernetes/Sun, 28 Jun 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/change-default-cluster-in-kubernetes/ If you have more than one cluster as illustrated in https://ismael.casimpan.com/quicktasks-k8s/list-nodes-in-kubernetes/, you can change it using command: 1kubectl config use-context <cluster_name_here> Use this command to verify the change: 1kubectl config get-contextshttps://quicktasks.ismael.casimpan.com/post/checking-pvc/Sun, 28 Jun 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/checking-pvc/ 1user@example:~$ kubectl get pvc --all-namespaces 2NAMESPACE NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE 3testing-icasimpan-com vol-mysql-mysql-0 Bound pvc-bd199911-e0e5-4327-885d-4902a599ebe2 10Gi RWO do-block-storage 12mhttps://quicktasks.ismael.casimpan.com/post/cluster-list-in-kubernetes/Sun, 28 Jun 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/cluster-list-in-kubernetes/ If you have a lot of kubernetes cluster, you will see the following: 1user@example:~$ kubectl config get-contexts 2CURRENT NAME CLUSTER AUTHINFO NAMESPACE 3* do-nyc1-kubernetes-tutorial do-nyc1-kubernetes-tutorial do-nyc1-kubernetes-tutorial-admin 4do-nyc3-infra do-nyc3-infra do-nyc3-infra-admin 5do-nyc2-devinfra do-nyc2-devinfra do-nyc2-devinfra-admin The one with asterisk (do-nyc1-kubernetes-tutorial) is your current cluster. So "kubectl" commands without specified cluster will default to it.https://quicktasks.ismael.casimpan.com/post/list-nodes-in-kubernetes/Sun, 28 Jun 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/list-nodes-in-kubernetes/ 1user@example:~$ kubectl get nodes 2NAME STATUS ROLES AGE VERSION 3pool-78osxtl1e3-3f4qg Ready <none> 72m v1.17.5 4pool-78osxtl1e3-3f4qw Ready <none> 71m v1.17.5https://quicktasks.ismael.casimpan.com/post/install-using-helm/Sun, 28 Jun 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/install-using-helm/ Say you want install jenkins and corresponding repo already added. 1user@example:~$ helm install jenkins codecentric/jenkins 2NAME: jenkins 3LAST DEPLOYED: Sun Jun 28 09:59:52 2020 4NAMESPACE: default 5STATUS: deployed 6REVISION: 1 7TEST SUITE: None 8NOTES: 9************************************************************************ 10* * 11* Jenkins Helm Chart by codecentric AG * 12* * 13************************************************************************ 1415In case the chart was installed with the default configuration and you did not 16configure an admin user, Jenkins creates one per default.https://quicktasks.ismael.casimpan.com/post/connection-to-server-refused/Sat, 27 Jun 2020 00:20:25 +0800https://quicktasks.ismael.casimpan.com/post/connection-to-server-refused/ When you see similar error as below: 1user@example:~$ kubectl get nodes 2The connection to the server localhost:8080 was refused - did you specify the right host or port? Check for the "$KUBECONFIG" if set and "kubectl config view" output. Chances are, both are empty like below: 1user@example:~$ echo $KUBECONFIG 1user@example:~$ kubectl config view 2apiVersion: v1 3clusters: null 4contexts: null 5current-context: "" 6kind: Config 7preferences: {} 8users: null In this example, we're using the DOKS or DigitalOcean Managed Kubernetes.