Kubernetes - V3

Note:

V1 & V2 were mostly to learn the basic concepts of Kubernetes. I didn't want to modify them as I'd like to keep the learning steps available. Hence, the multiple repos.

• Users-API: Creates users and Logs users
• Auth-API: Generate and verify tokens for authenticated users
• Tasks-API: Stores users tasks in a file and received a token to be verified
• Client: Calls the Tasks API through Nginx Reverse Proxy

Note: Dummy data, there is no database (so far)

• Created user-API
• Created auth-API
• Created tasks-API
• Tested each app individually with npm start and Postman

• Created Dockerfile for each API
• Created docker-compose
• Replaced API url with docker network name
• Tested with :

docker-compose up --build

Note: Didn't add volumes, I want to focus on containers and pods interactions

• Verify that Minikube is up and running with

minikube status

• If it's not running, then :

minikube start

• Check if there is no ungoing deployments or services

kubectl get deployments
kubectl get services

• Modified users-app.js so it doesn't make any requests for now to auth-api
• Built image and pushed it to DockerHub

docker build -t alisonv2/kub-v3-users .
docker push alisonv2/kub-v3-users

• Created users-deployment.yaml and applied it
• Verify that pod is up and running
• Created users-service.yaml and applied it
• Expose service with Minikube
• Tested the service with Postman at {minikube-url}/login (passing email and password)

cd ..
cd kubernetes
kubectl apply -f users-deployment.yaml
kubectl get pods
kubectl apply -f users-service.yaml
minikube service users-service

• Reverted users-api code so it does send requests to the auth-api
• Replaced API urls with environment variables so the exact url used can be changed depending on which environment we're running
• Added environment to docker-compose
• Built new image only for auth and pushed it to DockerHub

cd auth-api
docker build -t alisonv2/kub-v3-auth .
docker push alisonv2/kub-v3-auth

• Created auth-deployment inside users-deployment so it doesn't create another pod. The goal is to have auth and users as two different containers inside the same pod.
• Updated users image

cd ..
cd users-api
docker build -t alisonv2/kub-v3-users .
docker push alisonv2/kub-v3-users

• Provide AUTH_ADDRESS for Pod-internal communication
• Applied updated users-deployment
• Check if both containers are running (should see 2/2 Running and 1/1 Terminating)

cd ..
cd kubernetes
kubectl apply -f users-deployment.yaml

• Signup test with Postman: Tests the users-api

• Login test with Postman: Tests users/auth APIs communication, as the token is created in the auth-api

• Created auth-deployment.yaml
• Created auth-service.yaml
• Chosed ClusterIP as a service type so the auth-api is not exposed outside the cluster
• Modified get adress in users-app.js to used env variables provided by kubernetes (ALLCAPSSERVICENAME_SERVICE_SERVICE_HOST)
• Added the same env name to docker-compose
• Modified env in users-deployment
• Applied auth-deployment and service
• Reapplied users-deployment (As the file didn't change, I deleted the currently running one so the new one is applied.)
• Checked if pods are up and running

# Make sure you're in users-api folder
docker build -t alisonv2/kub-v3-users .
docker push alisonv2/kub-v3-users
cd ..
cd kubernetes
kubectl apply -f auth-service.yaml,auth-deployment.yaml
kubectl delete -f users-deployment.yaml
kubectl apply -f users-deployment.yaml
kubectl get pods

Note: I kept the manually set env variable for the first call, so I can have both options as a reminder.

process.env.NAME_SERVICE_SERVICE_HOST

- Option 2: CoreDNS for automatic domain names

value: "servicename.namespace"

The namespaces are available with

kubectl get namespaces

• Tested with Postman

• Created tasks-deployment.yaml and service-deployment.yaml with env variables
• Modified API url in tasks-app.js to use env variables
• Modified docker-compose to set env variables
• Built and pushed tasks image to DockerHub
• Applied deployment and service
• Checked running deployments & pods
• Checked services

docker build -t alisonv2/kub-v3-tasks .
docker push alisonv2/kub-v3-tasks
cd ..
cd kubernetes
kubectl apply -f tasks-service.yaml,tasks-deployment.yaml
kubectl get deployments
kubectl get pods

• Check what services are running with

kubectl get services

• Start tasks service and get the URL to send requests to the tasks service

minikube service tasks-service

• Test with Postman:

Note: As we don't have any tasks yet, the get request will send an error. So first, we need to send a POST request with a header and body.

Now we can send the get request, with the same header.

• Created Client with CRA
• Created Dockerfile with Node
• Created nginx config file
• Added Nginx to client's Dockerfile
• Built and ran container

docker build -t alisonv2/kub-v3-client .
docker run -p 80:80 --rm -d alisonv2/kub-v3-client

• Created client-deployment and service
• Built and pushed image to DockerHub
• Applied deployment and service
• Checked if services and pods are all available

• Exposed client service

minikube service client-service

• Tweaked styles to make it look a tiny bit better
• Added window location reload for auto fetch
• Rebuilt image
• Pushed image to DockerHub
• Removed deployment
• Reapplied deployment
• Checked if everything is still up and running

docker build -t alisonv2/kub-v3-client .
docker push alisonv2/kub-v3-client:latest
cd ..
cd kubernetes
kubectl delete -f client-deployment.yaml
kubectl apply -f client-deployment.yaml
kubectl get deployments