Using Flavors

Now that you understand flavors and JSON Patch, let’s see how to use them in practice.

The —flavor Flag

Most EMB commands accept the --flavor flag:

emb <command> --flavor production

The flag comes after the command.

Building with Flavors

Build production images:

emb resources build --flavor production

This applies the production flavor, changing:

• Docker target from development to production
• Environment variables as configured

Viewing Flavor Effects

Compare base vs flavored configuration:

# Base configuration
emb config print

# With production flavor
emb config print --flavor production

Check specific values using the defaults section:

emb config print | grep -A 3 "^defaults:"

defaults:
  docker:
    tag: ${env:DOCKER_TAG}
    target: development

emb config print --flavor production | grep -A 3 "^defaults:"

defaults:
  docker:
    tag: ${env:DOCKER_TAG}
    target: production

Running with Flavors

Start services with production settings:

emb up --flavor production

This:

1. Applies the flavor patches
2. Builds images with the production target
3. Starts services with production environment variables

Flavor in CI/CD

Flavors are perfect for CI/CD pipelines:

# Development builds (default)
emb resources build
emb up -d
npm test

# Staging deployment
emb resources build --flavor staging
docker push myregistry/app:staging

# Production deployment
emb resources build --flavor production
docker push myregistry/app:latest

Component-Level Flavor Patches

Components can add their own flavor patches:

cat api/Embfile.yml | grep -A 5 "^flavors:"

flavors:
  production:
    patches:
      - op: replace
        path: /resources/image/params/target
        value: production

This ensures the API uses the production Docker target when building with --flavor production.

Flavor Inheritance

When both project and component define the same flavor:

1. Project-level patches apply first
2. Component-level patches apply second

This lets you:

• Set global defaults at project level
• Override specific components as needed

Summary

You’ve completed the EMB tutorials! You now know how to:

• Hello World: Minimal configuration and auto-discovery
• Fullstack App: Tasks, environment variables, Docker Compose
• Microservices: Dependencies and build ordering
• Production Ready: Multi-stage builds and flavors

Next Steps

• Check the Advanced documentation for executors, interactive tasks, and more
• Learn about Secrets Management for Vault integration
• Read the Reference for complete configuration options

Happy building!