ks1.md

Kubernetes series part 1

The objective here is to create a minimal react app and hook it up with kubernetes.

Build a React app

• we start with a react application similar to the result of create react app as our baseline.

1. navigate to ks1

   ➜ pwd
       ~/dev/github/redgate/ks/ks1

2. build app

   ➜ cd ./app
   ➜ yarn
       yarn install v1.1.0
       [1/4] 🔍  Resolving packages...
       [2/4] 🚚  Fetching packages...
       [3/4] 🔗  Linking dependencies...
       [4/4] 📃  Building fresh packages...
       success Saved lockfile.
       ✨  Done in 2.92s.
   ➜ yarn start
       Compiled successfully!
   
       You can now view app in the browser.
   
       Local:            http://localhost:3000/
       On Your Network:  http://192.168.0.6:3000/
   
       Note that the development build is not optimized.
       To create a production build, use yarn build.

   This should serve your website at http://localhost:3000/

   

Move app into kubernetes

1. start minikube

   ➜ minikube start

2. switch to minikube context

   ➜ eval $(minikube docker-env)

   If you ever need to switch back to your machine's context do:

   ➜ eval $(docker-machine env -u)

3. create apps Dockerfile

   The docker image is based on the following docker file File: ./ks1/web/Dockerfile

   FROM node:8.6.0
   
   ADD ./app /app
   
   WORKDIR /app
   
   EXPOSE 3000
   
   RUN yarn install
   RUN yarn
   CMD ["yarn", "start"]

4. create the docker image

   ➜ docker build -f ./web/Dockerfile -t kswebimage .

5. create kubernetes deployment file

   File: ./ks1/config/dev.ks.deployment.yaml

   apiVersion: extensions/v1beta1
   kind: Deployment
   metadata:
   creationTimestamp: null
   labels:
       run: ksweb
   name: ksweb
   spec:
   replicas: 1
   selector:
       matchLabels:
       run: ksweb
   strategy: {}
   template:
       metadata:
       creationTimestamp: null
       labels:
           run: ksweb
       spec:
       containers:
       - image: kswebimage:latest
           name: ksweb
           imagePullPolicy: IfNotPresent
           ports:
           - containerPort: 3000
           resources: {}
   status: {}

6. create kubernetes service file

   File: ./ks1/config/dev.ks.service.yaml

   apiVersion: v1
   kind: Service
   metadata:
   creationTimestamp: null
   labels:
       run: ksweb
   name: ksweb
   spec:
   ports:
   - port: 80
       protocol: TCP
       targetPort: 3000
   selector:
       run: ksweb
   type: LoadBalancer
   status:
   loadBalancer: {}

7. create deployment and service

   ➜ kubectl create -f ./config/dev.ks.deployment.yaml
   deployment "ksweb" created
   
   ➜ kubectl create -f ./config/dev.ks.service.yaml
   service "ksweb" created

8. check cluster status

   ➜ kubectl get all
   NAME           DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
   deploy/ksweb   1         1         1            1           2m
   
   NAME                  DESIRED   CURRENT   READY     AGE
   rs/ksweb-1832552125   1         1         1         2m
   
   NAME           DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
   deploy/ksweb   1         1         1            1           2m
   
   NAME                        READY     STATUS    RESTARTS   AGE
   po/ksweb-1832552125-6p0z3   1/1       Running   0          2m

9. check web logs

   ➜ kubectl logs ksweb-1832552125-6p0z3
   yarn run v1.1.0
   $ react-scripts start
   Starting the development server...
   
   Compiled successfully!
   
   You can now view app in the browser.
   
   Local:            http://localhost:3000/
   On Your Network:  http://172.17.0.2:3000/
   
   Note that the development build is not optimized.
   To create a production build, use yarn build.

10. service app

    Get URL and navigate to it.

    ➜ minikube service ksweb --url

11. delete app

    To delete deployment and service:

    ➜ kubectl delete -f ./config/dev.ks.deployment.yaml
    ➜ kubectl delete -f ./config/dev.ks.service.yaml

    To delete image

    ➜ docker rmi kswebimage

    To switch context

    ➜ eval $(docker-machine env -u)

    To stop minikube

    ➜ minikube stop