Deploy a Go App

This guide explains how to deploy a Go application on Koyeb using:

1. Git-driven deployment to automatically build and deploy a new version of your application each time a change is detected on your branch.
2. Pre-built containers you can deploy from any public or private registry.

To successfully follow this documentation, you will need to have a Koyeb account. You can optionally install the Koyeb CLI if you prefer to follow this guide without leaving the terminal.

You can deploy and preview the sample Go application that we will run on Koyeb in this guide using the Deploy to Koyeb button below.

You can access the repository used for this documentation here.

Create the Go app

Get started by creating a minimalistic Go application that we will deploy on Koyeb. You will need Go installed on your machine.

In your terminal, run the following commands to create the directory that will hold the application code:

mkdir example-go
cd example-go

Koyeb detects Go applications when one of the following requirements is met. In this guide, we will use Go module to trigger the detection.

Run the go mod init command with your module path, here we use github.com/koyeb/example-golang. When you publish a module, this must be a path from which your module can be downloaded by Go tools, such as your code's repository.

$ go mod init github.com/koyeb/example-golang
go: creating new go.mod: module github.com/koyeb/example-golang

Create a new file main.go and copy the following code into it:

package main

import (
	"fmt"
	"log"
	"net/http"
	"os"
)

func main() {
	port := os.Getenv("PORT")

	if port == "" {
		port = "8080"
	}

	http.HandleFunc("/", HelloHandler)

	log.Println("Listening on port", port)
	log.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", port), nil))
}

func HelloHandler(w http.ResponseWriter, _ *http.Request) {
	fmt.Fprintf(w, "Hello from Koyeb")
}

The code above runs an HTTP server using the standard net/http library and responds Hello from Koyeb to GET / requests.

Run the Go app locally

Launch the application locally to make sure everything is running as expected.

go run main.go

You can now access the application at http://localhost:8080.

Deploy the Go app on Koyeb using git-driven deployment

In the project directory, initialize a new git repository by running the following command:

git init

We will use this repository to version the application code and push the changes to a GitHub repository. If you don't have an existing GitHub repository to push the code to, you can create a new one and run the following commands to commit and push changes to your GitHub repository:

git add .
git commit -m "Initial commit"
git remote add origin git@github.com:<YOUR_GITHUB_USERNAME>/<YOUR_REPOSITORY_NAME>.git
git push -u origin main

Via the Koyeb control panel

To deploy the Go app on Koyeb, using the control panel follow the steps below:

1. Create a new Koyeb App
2. Select GitHub as the deployment option
3. Choose the GitHub repository and branch contaning your application code
4. Name your service, for instance go-koyeb
5. Click the Deploy button.

A Koyeb App and Service have been created. Your application is now going to be built and deployed on Koyeb. Once the build has finished, you will be able to access your application running on Koyeb by clicking the URL ending with .koyeb.app.

Via Koyeb CLI

To deploy the Go app on Koyeb using the Koyeb CLI, run the following command in your terminal:

koyeb app init example-go \
  --git github.com/<YOUR_GITHUB_USERNAME>/<YOUR_REPOSITORY_NAME> \
  --git-branch main \
  --ports 8080:http \
  --routes /:8080 \
  --env PORT=8080

Make sure to replace <YOUR_GITHUB_USERNAME>/<YOUR_REPOSITORY_NAME> with your GitHub username and repository name.

Access deployment logs

To track the app deployment and visualize build logs, execute the following command:

koyeb service logs example-go/example-go -t build

Access your app

Once the deployment of your application has finished, you can retrieve the public domain to access your application by running the following command:

$ koyeb app get example-go
ID      	NAME         	DOMAINS                          	CREATED AT
55d75993	example-go  	["example-go-myorg.koyeb.app"]	20 Sep 22 09:55 UTC

Access runtime logs

With your app running, you can track the runtime logs by running the following command:

koyeb service logs example-go/example-go -t runtime

Deploy the Go app on Koyeb using a pre-built container

Alternatively to using git-driven deployment, you can deploy a pre-built container from any public or private registry. This can be useful if your application needs specific system dependencies or you need more control over how the build is performed.

To dockerize the Go application, create a Dockerfile in your project root directory and copy the content below:

FROM golang:1.19-alpine AS builder
WORKDIR /app
COPY . .
RUN go mod download
RUN go build -o ./example-golang ./main.go


FROM alpine:latest AS runner
WORKDIR /app
COPY --from=builder /app/example-golang .
EXPOSE 8080
ENTRYPOINT ["./example-golang"]

The Dockerfile above provides the minimum requirements to run the Go application. You can easily extend it depending on your needs.

To build and push the Docker image to a registry and deploy it on Koyeb, refer to the Deploy an app from a Docker image.