Seamlessly Embed Files Into Your Go Binary

Incorporating YAML, JSON, or other configuration files into your Go application is becoming a standard practice, these files are often being referenced by file paths within the project. Although the go-build process completes smoothly, executing the standalone binary can result in a 'file not found' error. This means you have to keep these setting files close to your app wherever you run it.

To circumvent this issue, Go offers a powerful feature known as embed. This allows developers to include their files directly within the binary by creating an embedded file system.

Usage

import "embed"

//go:embed config.yaml
var embedFS embed.FS

# access config file
config, _ := embedFS.ReadFile("config.yaml")

You can even embed a list of directories as part of your go binary,

import "embed"

//go:embed templates/* config/*
var embedFS embed.FS

# access email template
template, _ := embedFS.ReadFile("templates/email.hbs")

This feature enables you to run the go binary standalone without any external dependencies.

For more details please check the go embed documentation.

Comments

[Siwalik Mukherjee]

Nice read Prakash, can go:embed be used to embed dynamic content generated during runtime?

[prakash chokalingam]

I don't think so @siwalikm, We can't write files within the embed fs dynamically, It can be used only to read. You can utilize the actual file system (pkg.go.dev/os) to read and write files dynamically.