Tasks

Tasks are scripts you can run across your monorepo. They can be defined at the project level (in .emb.yml) or at the component level (in Embfile.yml).

Listing Tasks

View all available tasks:

emb tasks

 NAME   COMPONENT  DESCRIPTION                         ID
----------------------------------------------------------------
 build             Build the entire project            build
 deps              Install project dependencies        deps
 setup             Set up the development environment  setup
 fail   api        A task that will fail               api:fail
 lint   api        Run linter on API code              api:lint
 test   api        Run API tests                       api:test
 test   web        Run frontend tests                  web:test

Tasks without a component are project-level tasks. Tasks with a component (like api:test) are component-specific.

Project-Level Tasks

Defined in .emb.yml, these run in the project root context:

tasks:
  setup:
    description: Set up the development environment
    script: |
      echo "Setting up $ENV environment"

Run with:

emb run setup

Component Tasks

Defined in a component’s Embfile.yml:

api/Embfile.yml

tasks:
  test:
    description: Run API tests
    script: npm test

Run with the full task ID:

emb run api:test

Task Variables

Tasks can define their own variables:

tasks:
  setup:
    vars:
      ENV: ${env:NODE_ENV:-development}
    script: |
      echo "Setting up $ENV environment"

The vars section defines variables available to the script. They can reference environment variables with defaults.

Task Prerequisites

Tasks can depend on other tasks:

tasks:
  deps:
    description: Install project dependencies
    script: |
      echo "Installing dependencies..."

  build:
    description: Build the entire project
    pre: ['deps']
    script: |
      echo "Building project..."

When you run emb run build, EMB automatically runs deps first.

Running Tasks

Run a project-level task:

emb run setup

This outputs:

Setting up development environment

Run a component task:

emb run api:test

Task Output

By default, task output is displayed in real-time. Task logs are also saved to .emb/default/logs/tasks/.

Handling Failures

If a task fails, EMB reports the error:

emb run api:fail

This would exit with a non-zero code, useful for CI/CD pipelines.

Next Step

Continue to Docker Compose to learn about running multi-service applications.