How to Embed a Build-Time Command Dependency (e.g., `github.com/aprice/embed/cmd/embed`) in Go Modules?

Embedding Command Dependency in Go Modules

Introduction

Go modules, introduced in Go 1.11, provide dependency management for Go projects. Besides runtime dependencies, users may need to utilize go modules during the build process, specifically for tools that run during the go generate command.

Question

How can I incorporate a specific build dependency, such as github.com/aprice/embed/cmd/embed, and execute it from a specific directory? Is go get the appropriate tool for this task?

Answer

Using the following methods, you can embed a command dependency in Go modules:

Creating a "Tools" Package

1. Create a tools directory within your project:

   mkdir -p internal/tools

2. Place the tools package within this directory, as shown below:

// internal/tools/tools.go
// +build tools

package tools

import (
    _ "github.com/UnnoTed/fileb0x"
)

3. Note that the build tag specifies when the file should be compiled and can be customized to your project's requirements.

Updating go.mod

1. Run go mod tidy to update your go.mod file and include the dependency.
2. If this fails, try executing additional commands such as go get, go generate, or go install.

Vendoring

1. Execute go mod vendor to download the source code for all dependencies listed in go.mod.
2. Modify your build commands (e.g., go build, go generate) to include the -mod=vendor flag. This ensures that your project uses the vendored dependencies.

Additional Notes

• If you encounter an error stating that your program is not an importable package, create a tools package and import the dependency there.
• Vendoring is crucial for utilizing the module cache and avoiding dependency conflicts.

The above is the detailed content of How to Embed a Build-Time Command Dependency (e.g., `github.com/aprice/embed/cmd/embed`) in Go Modules?. For more information, please follow other related articles on the PHP Chinese website!