Project Architecture Explanation

• cmd/: Contains the main entry point (main.go) that boots up your HTTPS server.
• pkg/: Contains core business logic split into modules:
• server/: Handles setting up the HTTPS server, including TLS configuration and middleware.
• handlers/: Contains HTTP handlers for different endpoints (authentication, user management, etc.).
• mqtt/: Holds the MQTT client code that your services can use to communicate with the MQTT broker.
• configs/: Houses configuration files (YAML, JSON, etc.) to manage environment-specific settings.
• deployments/: Contains all deployment-related files:
• kubernetes/: Kubernetes manifests for deploying your HTTPS service and MQTT broker.
• docker-compose.yml: (Optional) Local multi-container orchestration configuration.
• Dockerfile: Defines how your HTTPS service container is built.
• go.mod and go.sum: Manage Go module dependencies.

Docker

Build container image:

docker build -t @username/https-server:latest .

Launch container image mounting in the specified path the certificates for secure communication:

docker run -it -v local_path:/etc/https-server/certs @username/https-server:latest

Inspect container

docker exec -it container_id /bin/bash

Kubernetes

MQTT

• Apply MQTT deployment for communication between microservices

kubectl apply -f deployments/kubernetes/mqtt/mqtt-deployment.yaml

• Apply MQTT service

kubectl apply -f deployments/kubernetes/mqtt/mqtt-service.yaml

• Verify deployment and check service is running

kubectl get pods -l app=mqtt
kubectl get svc mqtt-service

HTTPS Server

Once you build and push the https server docker image, you can start your cluster with a Docker driver by using minikube.

You must apply all the deplyments to create the pod and run the containers declared in each deployment.

• Apply Config Map

kubectl apply -f deployments/kubernetes/configmap.yaml

• Apply Secret

It should contains your certificate and key encoded in base64. Please, update this fields according to your certificate and private key PEM files.

Once you finish the encoding, update both cert.pem and key.pem values. Then, you can apply the config as follows:

kubectl apply -f deployments/kubernetes/secret.yaml

• Apply HTTPS server config

In order to gather the deployments to the main go, you need to apply this congiuration file:

kubectl apply -f deployments/kubernetes/https-server-deployment.yaml

Make sure the pod is running

kubectl get pods -l app=https-server 

Expose deployment through a service

kubectl apply -f deployments/kubernetes/https-server-service.yaml

Check service has been deployed correctly

kubectl get svc https-server  

You should be able to see something like:

NAME           TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
https-server   ClusterIP   10.111.17.234   <none>        8443/TCP   24h

meaning you can test connection, via for example port forwarding as

kubectl port-forward svc/https-server 8443:8443
curl -k https://localhost:8443/health

or

curl.exe -4 -k https://127.0.0.1:8443/health

• Stop running deployment, services and minikube

kubectl delete deployment https-server
kubectl delete service https-server
minikube stop

• Debug Pod

kubectl get pods
kubectl exec -it <pod-name> -- /bin/sh