Nicolas De Loof
720da68475
Eleven comments in the reconciler and its neighbors justified decisions
by pointing at code that no longer exists ('matching the previous
ensureNetwork behavior', 'same way as convergence.go:138-160' — lines
that today hold unrelated code) instead of stating the behavior and its
reason. A reader following those pointers finds nothing, or worse,
something else.
Each is rewritten as a self-contained behavioral statement. Two carry
real weight:
- reconcileService's up-to-date branch now says explicitly that
starting containers is NOT the plan's job (a separate start phase in
start.go does it) — the previous wording invited 'fixing' the
StateCreated case;
- sortContainers now documents that its ordering IS the scale-down
policy (the tail it produces is what i >= expected trims), instead of
referencing stale line numbers.
Part of #14074 (A: the code misdescribes its own structure).
Signed-off-by: Nicolas De Loof <[email protected]>
Table of Contents
Docker Compose
Docker Compose is a tool for running multi-container applications on Docker
defined using the Compose file format.
A Compose file is used to define how one or more containers that make up
your application are configured.
Once you have a Compose file, you can create and start your application with a
single command: docker compose up.
Note
: About Docker Swarm Docker Swarm used to rely on the legacy compose file format but did not adopt the compose specification so is missing some of the recent enhancements in the compose syntax. After acquisition by Mirantis swarm isn't maintained by Docker Inc, and as such some Docker Compose features aren't accessible to swarm users.
Where to get Docker Compose
Windows and macOS
Docker Compose is included in Docker Desktop for Windows and macOS.
Linux
You can download Docker Compose binaries from the release page on this repository.
Rename the relevant binary for your OS to docker-compose and copy it to $HOME/.docker/cli-plugins
Or copy it into one of these folders to install it system-wide:
/usr/local/lib/docker/cli-pluginsOR/usr/local/libexec/docker/cli-plugins/usr/lib/docker/cli-pluginsOR/usr/libexec/docker/cli-plugins
(might require making the downloaded file executable with chmod +x)
Quick Start
Using Docker Compose is a three-step process:
- Define your app's environment with a
Dockerfileso it can be reproduced anywhere. - Define the services that make up your app in
compose.yamlso they can be run together in an isolated environment. - Lastly, run
docker compose upand Compose will start and run your entire app.
A Compose file looks like this:
services:
web:
build: .
ports:
- "5000:5000"
volumes:
- .:/code
redis:
image: redis
Contributing
Want to help develop Docker Compose? Check out our contributing documentation.
If you find an issue, please report it on the issue tracker.
Legacy
The Python version of Compose is available under the v1 branch.