Develop is an optional part of the Compose Specification
Compose focuses on the development use-case of running applications on a local machine. It also supports some development hooks to improve the velocity of your local workflow, also known as your "inner loop". This document defines how Compose behaves to efficiently assist the developer.
This section defines the development constraints and workflows set by Compose. Only a subset of
Compose file services may require a
services: frontend: image: example/webapp build: ./webapp develop: watch: # sync static content - path: ./webapp/html action: sync target: /var/www ignore: - node_modules/ backend: image: example/backend build: ./backend develop: watch: # rebuild image and recreate service - path: ./backend/src action: rebuild
develop subsection defines configuration options that are applied by Compose to assist you during development of a service with optimized workflows.
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, see
Use Compose Watchopen_in_new.
action defines the action to take when changes are detected. If
action is set to:
rebuild, Compose rebuilds the service image based on the
buildsection and recreates the service with the updated image.
sync, Compose keeps the existing service container(s) running, but synchronizes source files with container content according to the
sync+restart, Compose synchronizes source files with container content according to the
targetattribute, and then restarts the container.
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
*matches 0 or more characters in a file name.
?matches a single character in file name.
*/*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
ignores file, and values set in the Compose model are appended.
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 attribute only applies when
action is configured for
sync. Files within
path with changes are synchronized
with container filesystem, so that the latter is always running with up-to-date content.