Initial Setup

1. Install kubectl: installation instructions for kubectl
2. Install minikube: installation instructions for minikube
3. Start the minikube cluster

minikube start --extra-config "apiserver.cors-allowed-origins=["http://boot.dev"]"

4. Start the cluster dashboard:

minikube dashboard --port=63840

5. Pull the SynergyChat Docker image

docker pull bootdotdev/synergychat

You're all set!

Deploying an Image

Let's deploy our SynergyChat docker image to our local k8s cluster:

kubectl create deployment synergychat-web --image=docker.io/bootdotdev/synergychat-web:latest

See whether the deployment was successful by running

kubectl get deployments

Resources inside of Kubernetes run on a private, isolated network. We'll need to do some port forwarding using kubectl

Get the name of the running pod:

kubectl get pods

NAME                               READY   STATUS    RESTARTS   AGE
synergychat-web-76dd6b65c5-xx58s   1/1     Running   0          10m

Set up port forwarding:

kubectl port-forward synergychat-web-76dd6b65c5-xx58s 8080:8080

Forwarding from 127.0.0.1:8080 -> 8080
Forwarding from [::1]:8080 -> 8080

You should now be able to access the web server at http://localhost:8080

Minikube runs on a single node, but it can run multiple pods by changing the "replicas" option in your deployment config.

Edit the deployment config:

kubectl edit deployment synergychat-web

Under the spec section, change the replicas field from 1 -> 2

spec:
  ...
  replicas: 2
  ...

You should now see two pods running:

kubectl get pods

NAME                               READY   STATUS    RESTARTS   AGE
synergychat-web-76dd6b65c5-nblp6   1/1     Running   0          7s
synergychat-web-76dd6b65c5-xx58s   1/1     Running   0          33m

Create a Config Map that defines the API_PORT for our upcoming backend API deployment

kubectl deploy -f api-configmap.yaml

Create a new deployment for our backend API

kubectl apply -f api-deployment.yaml

Create a Config Map for our Crawler app

kubectl apply -f crawler-configmap.yaml

Create a Deployment for the Crawler app

kubectl apply -f crawler-deployment.yaml

Create Services for our Web, API, and Crawler Services provide a stable endpoint to reach our apps since Pod IP's are always changing

• web-service.yaml: Endpoint for clients to connect to the web service
• api-service.yaml: Endpoint for clients to access the API
• crawler-service.yaml: Endpoint for our API to communicate with the crawler

Apply the configs to create the services:

kubectl apply -f web-service.yaml
kubectl apply -f api-service.yaml
kubectl apply -f crawler-service.yaml

Next we'll need to use the Gateway API to expose the services to the outside world

Install the Envoy Gateway implementation of the Gateway API

kubectl apply --server-side -f https://github.com/envoyproxy/gateway/releases/download/v1.5.1/install.yaml

app-gatewayclass.yaml creates a GatewayClass that we can later use to create the actual Gateway. Every Gateway needs to be associated with a GatewayClass

app-gateway.yaml creates the Gateway itself

web-httproute.yaml creates an HTTPRoute that defines the routing rules for our Gateway to our web service

api-httproute.yaml creates the same as above, but sets up routing rules for the API

In other words, any traffic to the synchat.internal domain name should be routed to the web-service and any traffic to synchatapi.internal domain name should be routed to the api-service

Now we need to add the synchat.internal and synchatapi.internal domain names to our local machine Add the following entries to /etc/hosts

127.0.0.1   synchat.internal
127.0.0.1   synchatapi.internal

Note: You also will need to add these to C:\Windows\System32\drivers\etc\hosts in order to access them from Windows

Now we can create a tunnel which lets us access the Gateway from our external browser

minikube tunnel -c

Create a web-configmap.yaml defining the WEB_PORT and API_URL env variables inside the Web Deployment

kubectl apply -f web-configmap.yaml

We also need to reference this configMap from web-deployment.yaml

# Under spec/containers
envFrom:
  - configMapRef:
    name: synergychat-web-configmap

Re-apply the changes to the Web Deployment

kubectl apply -f web-deployment.yaml

Useful Commands

Delete a pod

kubectl delete pod <pod_name>

View logs for a pod

kubectl logs <pod_name>