Web app deployment inside of Kubernetes with microk8s

based on the Kubernetes course:

 

1) install microk8s: sudo snap install microk8s

2) enable registry & dns: microk8s.enable registry dns

MONGODB deployment & service

3) configure the mongodb deployment

generate 2 secrets using md5sum from shell

MONGO_INITDB_ROOT_USERNAME=--insert_here_encrypted_username-- -e MONGO_INITDB_ROOT_PASSWORD=--insert_here_encrypted_password-- -e MONGO_INITDB_DATABASE=admin

4) apply the MongoDB database deployment and service

microk8s.kubectl apply -f mongodb-deployment.yaml

5) check the environment variables inside the container

5.1) enter inside the deployment:

microk8s.kubectl exec -it deployment.apps/mongodb-deployment sh

5.2) env

6.1) get inside the mongodb container:

from Docker: docker exec -it mongo bash

from Kubernetes: microk8s.kubectl exec -it mongodb-deployment--insert_your_deployment_id -- /bin/sh

6.2) authenticate to the mongodb database container:

mongo -u insert_here_encrypted_username -p insert_here_encrypted_password --authenticationDatabase admin

Our application deployment & service

7) build the docker image of our application:
docker build . -t localhost:32000/mongo-app:v1
8) test the image using port forwarding:
docker run -p 3000:3000 localhost:32000/mongo-app:v1

or: docker run  -it --rm -p 3000:3000 localhost:32000/mongo-app:v1

9) push the image into the kubernetes registry
docker push localhost:32000/mongo-app:v1

10) apply our custom application: microk8s.kubectl apply -f mongo.yaml

11) check whether the IP addresses of the service and pods match. This means that the service endpoints are correctly set and math the created pods:

microk8s.kubectl describe service
microk8s.kubectl get pod -o wide

Congratulations!