Go

This example shows how to migrate a Go application to Docker Hardened Images.

The following examples show Dockerfiles before and after migration to Docker Hardened Images. Each example includes four variations:

Before (Wolfi): A sample Dockerfile using Wolfi distribution images, before migrating to DHI
Before (DOI): A sample Dockerfile using Docker Official Images, before migrating to DHI
After (multi-stage): A sample Dockerfile after migrating to DHI with multi-stage builds (recommended for minimal, secure images)
After (single-stage): A sample Dockerfile after migrating to DHI with single-stage builds (simpler but results in a larger image with a broader attack surface)

Note
Multi-stage builds are recommended for most use cases. Single-stage builds are supported for simplicity, but come with tradeoffs in size and security.
You must authenticate to dhi.io before you can pull Docker Hardened Images. Use your Docker ID credentials (the same username and password you use for Docker Hub). If you don't have a Docker account, create one for free.
Run docker login dhi.io to authenticate.

#syntax=docker/dockerfile:1

FROM cgr.dev/chainguard/go:latest-dev

WORKDIR /app
ADD . ./

# Install any additional packages if needed using apk
# RUN apk add --no-cache git

RUN CGO_ENABLED=0 GOOS=linux go build -a -ldflags="-s -w" --installsuffix cgo -o main .

ENTRYPOINT ["/app/main"]

#syntax=docker/dockerfile:1

FROM golang:latest

WORKDIR /app
ADD . ./

# Install any additional packages if needed using apt
# RUN apt-get update && apt-get install -y git && rm -rf /var/lib/apt/lists/*

RUN CGO_ENABLED=0 GOOS=linux go build -a -ldflags="-s -w" --installsuffix cgo -o main .

ENTRYPOINT ["/app/main"]

#syntax=docker/dockerfile:1

# === Build stage: Compile Go application ===
FROM dhi.io/golang:1-alpine3.21-dev AS builder

WORKDIR /app
ADD . ./

# Install any additional packages if needed using apk
# RUN apk add --no-cache git

RUN CGO_ENABLED=0 GOOS=linux go build -a -ldflags="-s -w" --installsuffix cgo -o main .

# === Final stage: Create minimal runtime image ===
FROM dhi.io/golang:1-alpine3.21

WORKDIR /app
COPY --from=builder /app/main  /app/main

ENTRYPOINT ["/app/main"]

#syntax=docker/dockerfile:1

FROM dhi.io/golang:1-alpine3.21-dev

WORKDIR /app
ADD . ./

# Install any additional packages if needed using apk
# RUN apk add --no-cache git

RUN CGO_ENABLED=0 GOOS=linux go build -a -ldflags="-s -w" --installsuffix cgo -o main .

ENTRYPOINT ["/app/main"]