Compose profiles for selective services in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Compose profile in Docker Compose?

A Compose profile is a way to group services in a Docker Compose file so you can selectively start those services by enabling specific profiles (services without profiles always start too).

beginner

How do you define a profile for a service in a Docker Compose file?

You add a 'profiles' key under the service with a list of profile names. For example:<br>

services:
  web:
    image: nginx
    profiles:
      - frontend

beginner

How do you start Docker Compose with a specific profile?

Use the command: docker compose --profile <profile_name> up to start services in that profile (in addition to services without profiles).

intermediate

What happens if you run 'docker compose up' without specifying any profile?

Docker Compose starts all services that have no profile specified. Services assigned to profiles are not started unless their profile is enabled.

beginner

Why use Compose profiles for selective services?

Profiles help you manage complex projects by starting only the services you need for a specific task, like development, testing, or production, saving resources and time.

How do you specify a profile for a service in a Docker Compose file?

A Add a 'profiles' key with a list of profile names under the service

B Use 'profile:' with a single profile name under the service

C Add 'profile' as an environment variable

D Profiles are set only via command line, not in the file

The correct way is to add a 'profiles' key with a list of profile names under the service.

What command starts services in the 'frontend' profile only?

A docker compose up frontend

B docker compose --profile frontend up

C docker compose start frontend

D docker compose run frontend

Use 'docker compose --profile frontend up' to start services in the 'frontend' profile (in addition to services without profiles).

If a service has no profile defined, when does it start?

A Always, regardless of profiles specified

B Only with the 'default' profile explicitly enabled

C Never, it must have a profile

D Only when a profile is specified

Services without profiles always start when you run 'docker compose up', regardless of profiles specified.

Why might you use profiles in Docker Compose?

A To set network configurations

B To define environment variables

C To group services for selective startup

D To build images automatically

Profiles group services so you can start only the ones you want.

What happens if you run 'docker compose up' with no profiles specified?

A No services start

B All services start regardless of profiles

C Only services with profiles start

D Only services without profiles start

Only services without profiles start by default when no profile is specified.

Explain how to use Compose profiles to start only selected services in a Docker Compose project.

Think about grouping services and using command line to select them.

Describe the benefits of using Compose profiles in managing Docker services.

Consider how profiles help organize and control service execution.