Compose Develop Specification (original) (raw)

Develop is an optional part of the Compose Specification. It is available with Docker Compose version 2.22.0 and later.

This page defines how Compose behaves to efficiently assist you and defines the development constraints and workflows set by Compose. Only a subset of Compose file services may require a develop subsection.

The develop subsection defines configuration options that are applied by Compose to assist you during development of a service with optimized workflows.

watch

The watch attribute defines a list of rules that control automatic service updates based on local file changes. watch is a sequence, each individual item in the sequence defines a rule to be applied by Compose to monitor source code for changes. For more information, seeUse Compose Watch.

action

action defines the action to take when changes are detected. If action is set to:

• rebuild: Compose rebuilds the service image based on the build section and recreates the service with the updated image.
• restart: Compose restarts the service container. Available with Docker Compose version 2.32.0 and later.
• sync: Compose keeps the existing service container(s) running, but synchronizes source files with container content according to the target attribute.
• sync+restart: Compose synchronizes source files with container content according to the target attribute, and then restarts the container. Available with Docker Compose version 2.23.0 and later.
• sync+exec: Compose synchronizes source files with container content according to the target attribute, and then executes a command inside the container. Available with Docker Compose version 2.32.0 and later.

exec

Requires: Docker Compose2.32.2 and later

exec is only relevant when action is set to sync+exec. Like service hooks, exec is used to define the command to be run inside the container once it has started.

• command: Specifies the command to run once the container starts. This attribute is required, and you can choose to use either the shell form or the exec form.
• user: The user to run the command. If not set, the command is run with the same user as the main service command.
• privileged: Lets the command run with privileged access.
• working_dir: The working directory in which to run the command. If not set, it is run in the same working directory as the main service command.
• environment: Sets the environment variables to run the command. While the command inherits the environment variables defined for the service’s main command, this section lets you add new variables or override existing ones.

ignore

The ignore attribute can be used to define a list of patterns for paths to be ignored. Any updated file that matches a pattern, or belongs to a folder that matches a pattern, won't trigger services to be re-created. The syntax is the same as .dockerignore file:

• * matches 0 or more characters in a filename.
• ? matches a single character in filename.
• */* matches two nested folders with arbitrary names
• ** matches an arbitrary number of nested folders

If the build context includes a .dockerignore file, the patterns in this file is loaded as implicit content for the ignores file, and values set in the Compose model are appended.

include

It is sometimes easier to select files to be watched instead of declaring those that shouldn't be watched with ignore.

The include attribute can be used to define a pattern, or a list of patterns, for paths to be considered for watching. Only files that match these patterns will be considered when applying a watch rule. The syntax is the same as ignore.

path

path attribute defines the path to source code (relative to the project directory) to monitor for changes. Updates to any file inside the path, which doesn't match any ignore rule, triggers the configured action.

target

target attribute only applies when action is configured for sync. Files within path that have changes are synchronized with the container's filesystem, so that the latter is always running with up-to-date content.