Earthly Is Free — Makefile + Docker = Reproducible Builds

#devops #docker #tutorial #opensource

The Problem With CI/CD

Your build works locally but fails in CI. Different Node versions, missing system libraries, environment differences. Earthly fixes this.

What Earthly Does

Earthly = Makefile syntax + Docker isolation. Every step runs in a container. Same result everywhere.

Earthfile

VERSION 0.8

build:
    FROM node:20
    WORKDIR /app
    COPY package.json package-lock.json .
    RUN npm ci
    COPY . .
    RUN npm run build
    SAVE ARTIFACT dist AS LOCAL dist

test:
    FROM +build
    RUN npm test

docker:
    FROM +build
    EXPOSE 3000
    CMD ["node", "dist/server.js"]
    SAVE IMAGE my-app:latest

all:
    BUILD +test
    BUILD +docker

Usage

# Install
curl -sSfL https://earthly.dev/get-earthly | sh

# Run
earthly +build    # Build only
earthly +test     # Build + test
earthly +docker   # Build + create Docker image
earthly +all      # Everything

Why Earthly

Same build locally and in CI
Layer caching (fast rebuilds)
Multi-platform builds
Parallel execution
Works with any CI (GitHub Actions, GitLab, Jenkins)

Earthly vs Alternatives

Feature	Earthly	Makefile	Docker	Bazel
Reproducible	Yes	No	Partial	Yes
Caching	Docker layers	None	Layers	Advanced
Learning curve	30 min	10 min	1 hour	1 week
Language support	Any	Any	Any	Limited

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