Implementing a Go Service for Azure Kubernetes Service

Introduction
Prerequisites
Setup
Creating a Go Service
Deploying the Service to Azure Kubernetes Service
Conclusion

Introduction

In this tutorial, we will learn how to implement a Go service for Azure Kubernetes Service (AKS). Azure Kubernetes Service is a managed container orchestration service provided by Microsoft. By the end of this tutorial, you will understand how to create a Go service and deploy it to AKS. We will cover the setup process, creating a simple Go service, and deploying it to AKS.

Prerequisites

Before starting this tutorial, make sure you have the following:

Basic knowledge of Go programming language
An Azure account with access to Azure Kubernetes Service
Kubernetes command-line tool (kubectl) installed on your machine

Setup

Install the Go programming language on your machine by following the official installation guide at https://golang.org/doc/install.
Create an Azure Kubernetes Service (AKS) cluster by following the official documentation at https://docs.microsoft.com/en-us/azure/aks/kubernetes-walkthrough-portal. Make sure to note down the cluster details, such as the resource group, cluster name, and location.
Install the Kubernetes command-line tool (kubectl) by following the official installation guide at https://kubernetes.io/docs/tasks/tools/install-kubectl/. This tool will be used to interact with the AKS cluster.

Creating a Go Service

Open your favorite text editor or Go integrated development environment (IDE).
Create a new file named main.go and open it.

Add the following code to import the necessary packages:

 package main
    
 import (
 	"fmt"
 	"net/http"
 )

Define a handler function to handle HTTP requests. In this example, we will create a simple handler that returns a “Hello, World!” response.
```
 func helloHandler(w http.ResponseWriter, r *http.Request) {
 	fmt.Fprint(w, "Hello, World!")
 }
```

Create a main function to start the HTTP server and register the handler.

 func main() {
 	http.HandleFunc("/", helloHandler)
 	http.ListenAndServe(":8080", nil)
 }

Save the file and exit the text editor or Go IDE.
Test the Go service locally by running the following command in the terminal:
```
 go run main.go
```
Open your web browser and visit http://localhost:8080 to see the “Hello, World!” response.

Deploying the Service to Azure Kubernetes Service

Open a terminal or command prompt.
Authenticate with your Azure account by running the following command:
```
 az login
```
Set the active subscription to the desired Azure subscription:
```
 az account set --subscription <subscription_id>
```

Configure kubectl to connect to your AKS cluster:

 az aks get-credentials --resource-group <resource_group> --name <cluster_name>

Test whether you can connect to the AKS cluster by running the following command:
```
 kubectl get nodes
```
Build a Docker image of your Go service by running the following command in the terminal:
```
 docker build -t your-docker-username/go-service .
```
Push the Docker image to your Docker Hub registry:
```
 docker push your-docker-username/go-service
```
Create a Kubernetes deployment YAML file, such as deployment.yaml, and open it in a text editor.

Add the following YAML code to define the deployment:

 apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: go-service
 spec:
   replicas: 3
   selector:
     matchLabels:
       app: go-service
   template:
     metadata:
       labels:
         app: go-service
     spec:
       containers:
       - name: go-service
         image: your-docker-username/go-service
         ports:
         - containerPort: 8080

Save the file and exit the text editor.
Create the deployment by running the following command in the terminal:
```
kubectl apply -f deployment.yaml
```
Verify that the deployment was successful:
```
kubectl get deployments
```
Expose the deployment as a Kubernetes service by creating a service YAML file, such as service.yaml, and open it in a text editor.

Add the following YAML code to define the service:

apiVersion: v1
kind: Service
metadata:
  name: go-service
spec:
  type: LoadBalancer
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: go-service

Save the file and exit the text editor.
Create the service by running the following command in the terminal:
```
kubectl apply -f service.yaml
```
Verify that the service was created:
```
kubectl get services
```
Get the external IP address of the service:
```
kubectl get services go-service
```
Open your web browser and visit the external IP address to see the deployed Go service.

Conclusion

In this tutorial, we learned how to implement a Go service for Azure Kubernetes Service. We covered the setup process, creating a simple Go service, and deploying it to AKS. Now you have the knowledge to build and deploy your Go services on AKS. Experiment with different functionalities and explore more advanced features of AKS to enhance your applications.

Published: 27 May 2022