Docker Build Demo

This project demonstrates different approaches to building minimal Docker images using Go applications. It includes examples of building images with:

• scratch base image
• distroless base image

Overview

The goal of this project is to showcase how to create minimal, secure, and efficient Docker images for Go applications. Since Go compiles to a single static binary, it's ideal for use with minimal base images like scratch and distroless.

Why Minimal Images?

• Smaller size: Faster downloads and less storage.
• Security: Reduced attack surface due to fewer packages and tools.
• Efficiency: Less bloat, better performance.

Dockerfiles

Dockerfile.scratch

Uses the scratch base image, which is literally empty. The final image contains only the compiled Go binary.

Dockerfile.distroless

Uses Google's distroless base image, which includes only the runtime dependencies needed to run the application (e.g., CA certificates), without shell or package managers.

Usage

Build the Application

GOOS=linux go build -o main .

Build Scratch Image

docker build -f Dockerfile.scratch -t demo-scratch .

Build Distroless Image

docker build -f Dockerfile.distroless -t demo-distroless .

Run Containers

docker run -p 8080:8080 demo-scratch
docker run -p 8080:8080 demo-distroless

Project Files

• main.go: Simple HTTP server written in Go.
• go.mod: Go module definition.
• Dockerfile.scratch: Dockerfile using scratch base image.
• Dockerfile.distroless: Dockerfile using distroless base image.
• README.md: This file.

References

• GoogleContainer/distroless
• Docker Scratch
• Go Docker image best practices