Kubernetes series part 1

November 1, 2017 · View on GitHub

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.

navigate to ks1

➜ pwd
    ~/dev/github/redgate/ks/ks1

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

start minikube
```
➜ minikube start
```
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)
```

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"]

create the docker image

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

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: {}

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: {}

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

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

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.

service app

Get URL and navigate to it.
```
➜ minikube service ksweb --url
```

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