How to Deploy golang to production Step by Step

If you want to use supervisor instead of systemd to deploy and monitor you application you can checkout this article.

Golang is one of the best programming language to work with.It makes everything so easy during deployment as no dependencies or installation are needed.

In this tutorial am going to show you how to deploy a golang application to digital ocean.However you can use the same steps in any environment or hosting service.

Making A simple Go rest api

I assume at this point you have your go application ready but for the sake of clarity lets start by making a very small rest api that will fetch us some jobs.

You can skip this section and jump to the deployment steps.

This will be our project structure.

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 main.go
 handlers
    handlers.go
 models
    models.go

The handlers.go - has all the handlers(controllers) we want to hook to our routes

The models.go -This contains all our model definition which in this case is  our job model.

The main.go – This is our entry point where we shall serve our application from.

Defining our model

In this simple api we are going to use only one model.That is the job model.But in general an application has many models which may be defined here.

Write the following code in your models.go

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package models
type Job struct {
	ID int `json:"id"`
	Name string `json:"name"`
}

Writing a handler to get our jobs

Now that we have our model its time to write an endpoint that will fetch our jobs.The endpoint will return a json response which we can consume.

Lets go ahead and write our code in the handlers.go file.

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package handlers
import (
	"deploy-go/models"
	"net/http"
	"encoding/json"
)
//A handler to fetch all the jobs
func GetJobs(w http.ResponseWriter, r *http.Request) {
	//make a slice to hold our jobs data
	var jobs []models.Job
	///add some job to the slice
	jobs = append(jobs, models.Job{ID: 1, Name: "Accounting"})
	jobs = append(jobs, models.Job{ID: 2, Name: "Programming"})
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(jobs)
}

Adding A router to our api

In this tutorial i am going to use the Chi router  to handle our routing but feel free to use any router available.

You may check out  httprouter or even  gorrila mux but it all a matter of preference.

Open you main.go file and paste this code.

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package main

import (
	"deploy-go/handlers"
	"log"
	"net/http"
	"github.com/go-chi/chi"
)

func main() {
	router := chi.NewRouter()
	router.Get("/api/jobs", handlers.GetJobs)
	//run it on port 8080
	err := http.ListenAndServe("0.0.0.0:8080", router)
	if err != nil {
		log.Fatal(err)
	}
}

our simple api is now complete test it by running:

go run main.go on the terminal.

If you followed this code to the latter you can visit

http://localhost:8080/api/jobs

You should see the jobs displayed.

Deploying our go rest api to digital  ocean

Now that we have our app ready it is time to deploy it.

I assume that your serve is running on a linux droplet thus i am going to compile our application for linux.It does not matter which machine you are using for development as go allows you to build for any os.In my case i am using macos but i will show you how to use it to build for linux.

Building our app

Cd you project(where your main.go is located )and run this command to build for linux.

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GOOS=linux GOARCH=amd64 go build

if you look at you folder you will notice that a new file called jobs has been created.
This is the compiled binary file that is needed to execute our api.You just have to upload this binary file to your serve and run it.

Scp this binary file to the server(For instance for my case to upload it to my server i would write)

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scp jobs  [email protected]:/var/www/go

Replace the domain name with your droplet domain name or ip address and  (/var/www/go) with the location you want to store it.

Writing a systemd file to  manage our app

We  need a way to stop ,restart and start our app.For this we are going to use systemd which will simplify our job.
You can also use supervisor for this task.

Create a unit file with the extension .service within the /etc/systemd/system directory to begin:

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sudo nano /etc/systemd/system/jobs.service

Inside copy the following script.

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Description= instance to serve jobs api
After=network.target

[Service]
User=root
Group=www-data
ExecStart=/home/path/to/binary/you/uploaded(which in my case is/var/www/go/jobs)
[Install]
WantedBy=multi-user.target

Thats all is needed.

We can now start our script by simply running.

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sudo systemctl start jobs  

sudo systemctl enable jobs

Now visit the port you configured you go app to use (Which in my case is :8080) your app should be running and ready for use.

Configuring Nginx to Proxy Requests your go rest api

Using nginx with go is not really necessary .However i would advice on using it since it help you to manage security for your application as its very easy to add ssl with nginx.

It is also easier to configure load balancing with nginx

The nginx setup is very simple.

Begin by creating a new server block configuration file in Nginx sites-available directory.

We will simply call this file jobs to keep in line with the rest of the guide:

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sudo nano /etc/nginx/sites-available/jobs

Open up a server block and tell Nginx to listen on the default port 80.
We also need to tell it to use this block for requests for our server’s domain name or IP address:

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server {
listen 80 default_server;
listen [::]:80 default_server;
server_name example.com www.example.com ;  
location / {
        proxy_pass http://localhost:8080;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

Replace the port number with the port  you used.The server_name should also be replaced with you domain name.

To enable the Nginx server block configuration we have just created,we need to create a symbolic link of our conf file to the sites-enabled directory:

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sudo ln -s /etc/nginx/sites-available/jobs /etc/nginx/sites-enabled

We can test for syntax errors by typing:

sudo nginx -t

If this returns without indicating any issues, we can restart the Nginx process to read our new config:

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sudo systemctl restart nginx

Conclusion

In this tutorial we have seen how to deploy a golang app to digital ocean in linux.However you can user this same setup for any machine or server  running a linux distribution.
I hope this tutorial helped you to understand how to deploy a golang app.

You can read more of our golang articles and leave a comment.

Happy Coding