Kubectl by Marcos Benevides
:ID: ee377537-0c8d-48c9-a181-19a2cff8c4a7
Commands
- View cluster information
kubectl cluster-info
Apply & Create
- Just creates a resource
kubectl create ...
- Create or modify a resource
kubectl apply -f pod.yml
Delete
Deleting a pod won’t prevent it from being recreated.
kubectl delete pod [pod-name]
you need to delete it’s deployment.
kubectl delete deployment [deployment-name]
Describe
kubectl describe pods <...>
Get
- View all the resources
kubectl get all
- Get information about the pods
kubectl get pods --watch
kubectl get pods -o wide
- Get information about deployments
# Lists deployments and their labels
kubectl get deployment --show-labels
# Get deployments with a specific label
kubectl get deployment -l app=nginx
Port-forward
- Forward port to enables external calls
kubectl port-forward [pod-name] [external-port]:[internal-port]
# For instance...
kubectl port-forward [pod-name] 8080:80
YAML
Pod
apiVersion: v1
kind: Pod
metadata:
name: nginx
labels:
app: nginx
ref: stable
spec:
containers:
- name: nginx
image: nginx:alpine
ports:
- containerPort: 80
Pod Healthchecks
-
Probe Types
- Readiness Probe: Defines when should a container start receiving traffic
- Liveness Probe: Defines when a container is considered unhealthy and should, therefore, be restarted.
-
Action Types
- ExecAction
- TCPSocketAction
- HTTPGetAction
apiVersion: v1
kind: Pod
metadata:
name: nginx
labels:
app: nginx
ref: stable
spec:
containers:
- name: nginx
image: nginx:alpine
ports:
- containerPort: 80
livenessProbe:
httpGet:
path: /index.html
port: 80
initialDelaySeconds: 15
timeoutSeconds: 2
periodSeconds: 5
failureThreshold: 1
readinessProbe:
httpGet:
path: /index.html
port: 80
initialDelaySeconds: 5
periodSeconds: 10
failureThreshold: 1
resources:
limits:
memory: "128Mi" # 128 Mb
cpu: "200m" # 200 milicpu, i.e, 0.2 cpu or 20% cpu