hit_record

The steps to DevOps challenge:

Create APP and containerize it and push that to public docker hub.
Launch Jenkins through Docker Compose
Create 3 LXC Container for k3s
Create k3s Cluster on those
Deploy the hit_record APP with k3s

1. Build and Push Image

$ docker build -f Dockerfile -t <DOCKERHUB_USER>/hit_record:latest .

$ docker push <DOCKERHUB_USER>/hit_record:latest

Github Action:

name: Docker Image CI

on:
  release:
    types: [published]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Build the Docker image
      run: docker build . --file Dockerfile --tag ${{ secrets.DOCKERHUB_USERNAME }}/hitrecord:latest
    -
      name: Login to Docker Hub
      uses: docker/login-action@v1
      with:
        username: ${{ secrets.DOCKERHUB_USERNAME }}
        password: ${{ secrets.DOCKERHUB_TOKEN }}
    - name: Push the image
      run: docker push ${{ secrets.DOCKERHUB_USERNAME }}/hitrecord:latest

Needed to set the secret with api token collected from DOCKERHUB. This action do work for tag release published.

2. JenkinsServer

Need docker-compose.

$ cd JenkinsServer
$ docker-compose up -d

This will start the Jenkins Server.

3. Create 3 lxc container

$ sudo apt install lxd zfsutils-linux

Configure LXD

$ lxd init

$ lxc launch ubuntu:20.04 k1
$ lxc launch ubuntu:20.04 k2
$ lxc launch ubuntu:20.04 k3

4. Create k3s Cluster

$ git clone git@github.com:k3s-io/k3s-ansible.git;cd k3s-ansible;

First create a new directory based on the sample directory within the inventory directory:

cp -R inventory/sample inventory/k3s-cluster-inventory

Second, edit inventory/k3s-cluster-inventory/hosts.ini to match the system information gathered above. For example:

[master]
192.168.168.100

[node]
192.168.168.[101:102]

[k3s_cluster:children]
master
node

group_vars

---
k3s_version: v1.23.4+k3s1
ansible_user: root
systemd_dir: /etc/systemd/system
master_ip: "{{ hostvars[groups['master'][0]]['ansible_host'] | default(groups['master'][0]) }}"
extra_server_args: ""
extra_agent_args: ""

Also, to use the hosts created by LXC, needed to set ssh key to those and enable ssh properly.

Let's create:

ansible-playbook site.yml -i inventory/k3s-cluster-inventory/hosts.ini

It will create the cluster.

5. Deploy the hit_record APP with k3s

Need ingress

helm install hitrecord-ingress nginx-stable/nginx-ingress

$ cd deployment
$ kubectl apply -f .

This will deploy the application.

# kubectl apply -f .
deployment.apps/hit-record-api-v1-deployment created
service/hit-record-api-v1-service created
deployment.apps/hit-record-api-v2-deployment created
service/hit-record-api-v2-service created
configmap/hit-record-configmap created
ingress.networking.k8s.io/hitrecord-ingress created
deployment.apps/redis-deployment created
service/redis-service created

Need helm to install linkerd and inject linkerd

$ curl --proto '=https' --tlsv1.2 -sSfL https://run.linkerd.io/install | sh

$ cat hit_record_api_v1_deployment.yaml| linkerd inject - | kubectl apply -f -
$ cat hit_record_api_v2_deployment.yaml| linkerd inject - | kubectl apply -f -

Visualize

$ linkerd viz install | kubectl apply -f -
$ linkerd viz dashboard

% kubectl get pods                        
NAME                                                READY   STATUS    RESTARTS      AGE
hit-record-api-v1-deployment-68b97bb87-wlth2        1/1     Running   0             3m22s
hit-record-api-v2-deployment-767d67bb4d-cwckk       1/1     Running   0             3m21s
hit-record-release-nginx-ingress-64f777454d-6ctj2   1/1     Running   2 (10h ago)   18h
redis-deployment-756b4b8956-hbqmk                   1/1     Running   0             3m21s

As I was in need to deploy v1 to workernode1 and v2 to workernode2, rewritten deployment file:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hit-record-api-v1-deployment
  labels:
    app: hit-record-api-v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hit-record-api-v1
  template:
    metadata:
      labels:
        app: hit-record-api-v1
    spec:
      nodeName: workernode1
      containers:
      - name: hit-record-api-v1
        image: fahadahammed/hit_record:latest
        ports:
        - containerPort: 22000
        env:
          - name: API_VERSION
            valueFrom:
              configMapKeyRef:
                name: hit-record-configmap
                key: hit_record_api_v1
          - name: REDIS_HOST
            valueFrom:
              configMapKeyRef:
                name: hit-record-configmap
                key: redis_host

Let's try API access with version:

% curl http://hitrecord.example.com/api/v1/
{
  "datetime": "Sun, 06 Mar 2022 15:09:29 GMT", 
  "hit_count": 1, 
  "hostname": "hit-record-api-v1-deployment-68b97bb87-j8v6t", 
  "msg": "Welcome to hit_record! I am going to record the hit count in redis.", 
  "version": "v1"
}

% curl http://hitrecord.example.com/api/v2/
{
  "datetime": "Sun, 06 Mar 2022 15:09:32 GMT", 
  "hit_count": 2, 
  "hostname": "hit-record-api-v2-deployment-767d67bb4d-sc5zm", 
  "msg": "Welcome to hit_record! I am going to record the hit count in redis.", 
  "version": "v2"
}

I have made the routing based on api version on url.