Flavors Introduction

Flavors let you define environment-specific configuration variants without duplicating your entire configuration.

The Problem

Different environments need different settings:

Setting	Development	Staging	Production
NODE_ENV	development	staging	production
LOG_LEVEL	debug	info	warn
Docker target	development	development	production

Without flavors, you’d need separate config files for each environment.

The Solution: Flavors

Flavors define patches that modify your base configuration:

flavors:
  production:
    patches:
      - op: replace
        path: /env/NODE_ENV
        value: production

When you use --flavor production, EMB:

1. Loads your base configuration
2. Applies the flavor’s patches
3. Uses the modified configuration

Viewing Available Flavors

List defined flavors:

emb config print | grep -A 22 "^flavors:"

flavors:
  staging:
    patches:
      - op: replace
        path: /env/NODE_ENV
        value: staging
      - op: replace
        path: /env/LOG_LEVEL
        value: info
  production:
    patches:
      - op: replace
        path: /env/NODE_ENV
        value: production
      - op: replace
        path: /env/LOG_LEVEL
        value: warn
      - op: replace
        path: /defaults/docker/target
        value: production
      - op: add
        path: /defaults/docker/platform
        value: ${env:DOCKER_PLATFORM:-linux/amd64}

Base vs Flavored Configuration

Base Configuration

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

env:
  DOCKER_TAG: ${env:DOCKER_TAG:-latest}
  NODE_ENV: ${env:NODE_ENV:-development}
  LOG_LEVEL: ${env:LOG_LEVEL:-debug}

With Production Flavor

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

env:
  DOCKER_TAG: ${env:DOCKER_TAG:-latest}
  NODE_ENV: production
  LOG_LEVEL: warn

Notice how NODE_ENV and LOG_LEVEL changed from templates to fixed production values!

When to Use Flavors

Flavors are ideal for:

• Environment differences - dev/staging/production settings
• Feature flags - enabling/disabling features per environment
• Resource sizing - different memory limits, replicas
• Docker targets - development vs production builds

Component-Level Flavors

Components can also define flavors in their Embfiles:

cat api/Embfile.yml | head -15

description: Production-ready API with multi-stage builds

resources:
  image:
    type: docker/image
    publish: true
    params:
      target: development

tasks:
  test:
    description: Run tests
    pre:
      - lint
    script: npm test

When both project and component define the same flavor, both sets of patches are applied (component first, then project). If they touch the same key, the project-level patch wins.

Next Step

Continue to JSON Patch to learn about the patch operations in detail.