Home

Deploying a Stand-Alone Application

$ minikube dashboard

Imgur

Imgur

Imgur

Imgur Imgur

NOTE: Add the full URL in the Container Image field docker.io/library/nginx:alpine if any issues are encountered with the simple nginx:alpine image name (or use the k8s.gcr.io/nginx:alpine URL if it works instead)

Display details

Imgur

Imgur

Imgur

Imgur

List the Pods, along with their attached Labels

$ kubectl get pods -L k8s-app,blabla
NAME                        READY   STATUS    RESTARTS   AGE   K8S-APP     BLABLA
webserver-c8f4d5fbc-9j65j   1/1     Running   0          42m   webserver
webserver-c8f4d5fbc-hm9xt   1/1     Running   0          42m   webserver
webserver-c8f4d5fbc-mlzc9   1/1     Running   0          42m   webserver

Select the Pods with a given Label

$ kubectl get pods -l k8s-app=webserver
NAME                        READY   STATUS    RESTARTS   AGE
webserver-c8f4d5fbc-9j65j   1/1     Running   0          48m
webserver-c8f4d5fbc-hm9xt   1/1     Running   0          48m
webserver-c8f4d5fbc-mlzc9   1/1     Running   0          48m

$ kubectl get pods -l k8s-app=webserver1
No resources found in default namespace.

Delete the Deployment

$ kubectl delete deploy webserver
deployment.apps "webserver" deleted

$ kubectl get replicasets
No resources found in default namespace.

$ kubectl get pods
No resources found in default namespace.

Deploy application using CLI.

$ kubectl create deploy --help
Create a deployment with the specified name.

Aliases:
deployment, deploy

Examples:
  # Create a new deployment named my-dep that runs the busybox image.
  kubectl create deployment my-dep --image=busybox

Options:
      --allow-missing-template-keys=true: If true, ignore any errors in templates when a field or map key is missing in
the template. Only applies to golang and jsonpath output formats.
      --dry-run=false: If true, only print the object that would be sent, without sending it.
      --generator='': The name of the API generator to use.
      --image=[]: Image name to run.
  -o, --output='': Output format. One of:
json|yaml|name|go-template|go-template-file|template|templatefile|jsonpath|jsonpath-file.
      --save-config=false: If true, the configuration of current object will be saved in its annotation. Otherwise, the
annotation will be unchanged. This flag is useful when you want to perform kubectl apply on this object in the future.
      --template='': Template string or path to template file to use when -o=go-template, -o=go-template-file. The
template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].
      --validate=true: If true, use a schema to validate the input before sending it

Usage:
  kubectl create deployment NAME --image=image [--dry-run] [options]

Use "kubectl options" for a list of global command-line options (applies to all commands).

$ kubectl create deploy webserver --image=nginx:alpine -o yaml --dry-run=true > webserver.yaml

$ kubectl get deploy
No resources found in default namespace.

$ cat webserver.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: webserver
  name: webserver
spec:
  replicas: 1
  selector:
    matchLabels:
      app: webserver
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: webserver
    spec:
      containers:
      - image: nginx:alpine
        name: nginx
        resources: {}
status: {}

$ cat webserver.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx
  name: webserver
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:alpine
        name: nginx
        ports:
        - containerPort: 80


$ kubectl create -f webserver.yaml
deployment.apps/webserver created

$ kubectl get deploy,rs,pods
NAME                        READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/webserver   3/3     3            3           62s

NAME                                   DESIRED   CURRENT   READY   AGE
replicaset.apps/webserver-5c559d5697   3         3         3       62s

NAME                             READY   STATUS    RESTARTS   AGE
pod/webserver-5c559d5697-7bz8p   1/1     Running   0          62s
pod/webserver-5c559d5697-c5ncg   1/1     Running   0          62s
pod/webserver-5c559d5697-rlb26   1/1     Running   0          62s

$ kubectl create service --help
Create a service using specified subcommand.

Aliases:
service, svc

Available Commands:
  clusterip    Create a ClusterIP service.
  externalname Create an ExternalName service.
  loadbalancer Create a LoadBalancer service.
  nodeport     Create a NodePort service.

Usage:
  kubectl create service [flags] [options]

Use "kubectl <command> --help" for more information about a given command.
Use "kubectl options" for a list of global command-line options (applies to all commands).

$ kubectl create service nodeport web-service --tcp=80 --dry-run=true -o yaml > webserver-svc.yaml

$ cat webserver-svc.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    run: web-service
  name: web-service
spec:
  ports:
  - port: 80
    protocol: TCP
  selector:
    app: nginx
  type: NodePort

$ kubectl get services
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   4h44m

$ kubectl create -f webserver-svc.yaml
service/web-service created

$ kubectl get services
NAME          TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)        AGE
kubernetes    ClusterIP   10.96.0.1      <none>        443/TCP        4h45m
web-service   NodePort    10.100.52.43   <none>        80:30387/TCP   23s

$ kubectl expose deployment webserver --port=81 --target-port=80 --type=NodePort

$ kubectl get services
NAME          TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes    ClusterIP   10.96.0.1        <none>        443/TCP        4h54m
web-service   NodePort    10.100.52.43     <none>        80:30387/TCP   8m57s
webserver     NodePort    10.107.217.161   <none>        81:31838/TCP   16s

$ kubectl describe service web-service
Name:                     web-service
Namespace:                default
Labels:                   run=web-service
Annotations:              <none>
Selector:                 app=nginx
Type:                     NodePort
IP:                       10.100.52.43
Port:                     <unset>  80/TCP
TargetPort:               80/TCP
NodePort:                 <unset>  30387/TCP
Endpoints:                172.17.0.4:80,172.17.0.5:80,172.17.0.6:80
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>


$ kubectl describe node minikube | grep IP
  InternalIP:  192.168.99.101

$ kubectl describe services web-service | grep NodePort
Type:                     NodePort
NodePort:                 <unset>  30387/TCP

$ minikube ip
192.168.99.101

$ minikube service web-service
|-----------|-------------|-------------|-----------------------------|
| NAMESPACE |    NAME     | TARGET PORT |             URL             |
|-----------|-------------|-------------|-----------------------------|
| default   | web-service |             | http://192.168.99.101:30387 |
|-----------|-------------|-------------|-----------------------------|
* Opening service default/web-service in default browser...

Liveness and Readiness Probes.

Liveness

Liveness : Command

Liveness HTTP Request

livenessProbe:
      httpGet:
        path: /healthz
        port: 8080
        httpHeaders:
        - name: X-Custom-Header
          value: Awesome
      initialDelaySeconds: 3
      periodSeconds: 3

TCP Liveness Probe

livenessProbe:
      tcpSocket:
        port: 8080
      initialDelaySeconds: 15
      periodSeconds: 20

Readiness Probs