Dashboards
:::danger Ask someone for the dashboard urls :::
kubectx & kubens
% brew install kubectx
Switch Context and NameSpace
% kubectx # list contexts
docker-desktop
% kubectx --current # list current context
docker-desktop
% kubectx docker-desktop # set context
% kubens # list namespaces
default
kube-node-lease
kube-public
kube-system
postgres
% kubens --current # list current namespace
postgres
% kubens default # set namespace
% kubens - # set namespace to the prior one
Connect to a pod
% kubectl exec --stdin --tty <pod-name> -- /bin/bash
Other Commands
% kubectl get pods --all-namespaces
% kubectl config get-contexts
Logs with kubetail
Install
% asdf plugin-add kubetail https://github.com/janpieper/asdf-kubetail.git
% asdf install kubetail latest
% asdf global kubetail <version>
Use
% kubetail <service name>
Or with a specific namespace
KUBETAIL_NAMESPACE=my-namespace kubetail <pod name>
Kubectl useful commands
List all objects
Get object ID
List all services
% kubectl -n kube-system get services
or
% kubectl get services --all-namespaces
View Config
% kubectl config view
List and use contexts
% kubectl config get-contexts
% kubectl use-context <name>
List and use namespaces
% kubectl get namespaces
% kubectl config set-context --current --namespace=<name>
Pods
Get all pods
% kubectl get pods --namespace <namespace>
Describe pod
% kubectl describe pod <pod_name> --namespace <namespace>
Count pods
Restart a Pod
You can use the following methods to restart a pod with kubectl. Once new pods are re-created they will have a different name than the old ones. A list of pods can be obtained using the kubectl get pods command.
% kubectl rollout restart
This method is the recommended first port of call as it will not introduce downtime as pods will be functioning. A rollout restart will kill one pod at a time, then new pods will be scaled up. This method can be used as of K8S v1.15.
% kubectl rollout restart deployment <deployment_name> -n <namespace>
Services
Get services
% kubectl get svc
Describe service
% kubectl describe svc <service_name>
Get a token
% kubectl create token default
List Resources
% kubectl api-resources --namespaced=true
Specific resource get
% kubectl get secrets
Delete Resources
Delete all resources.
% kubectl delete all --all -n {namespace}
The previous command doesn’t delete admin level resource, using the following script will get rid of things such as limits, quotas, secrets, etc.
% kubectl delete "$(kubectl api-resources --namespaced=true --verbs=delete -o name | tr "\n" "," | sed -e 's/,$//')" --all
Create Secret
% kubectl -n auth0-inter create secret generic auth0-inter-management-client-secret --from-literal=auth0__management_client_secret='fuck-you-ezekiel' --from-file secret/
Get deployed image
% k get deployment -n <namespace> api -oyaml | grep -e "image:"
Port Forwarding
% kubectl port-forward -n default service/halleck-kube-prometheus-stack-grafana <from_port>:<to_port
Kubenetes with Docker Image
Build the image
% docker build -t jaiken/fast-api .
Docker login and push
% docker login && docker push jaiken/fast-api
Example deploy document, deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: fast-api-deployment
spec:
replicas: 2
selector:
matchLabels:
app: fast-api
template:
metadata:
labels:
app: fast-api
spec:
containers:
- name: fast-api
image: bravinwasike/fast-api
resources:
limits:
memory: "128Mi"
cpu: "500m"
ports:
- containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
name: fast-api-service
spec:
selector:
app: fast-api
ports:
- port: 80
targetPort: 8080
type: LoadBalancer
Apply deploy document
kubectl apply -f deploy.yaml
Create a Workstation Pod
ubuntu client
Connect
How to delete Persistent Volume stuck in terminating state?
Change state of the PV
Delete PV