Guillaume Lours
b212ce297c
errgroup.SetLimit(0) means "allow zero goroutines", not "unlimited",
and maxConcurrency's Go zero-value is 0 — only NewComposeService sets
it to -1 explicitly. Any composeService{} literal built without it
(common in tests) silently deadlocked at every call site that called
SetLimit unconditionally.
Separately, --parallel/COMPOSE_PARALLEL_LIMIT was only ever wired
into pull, push, and the dependency-graph traversal, despite the docs
promising a generic bound on "concurrent engine calls". Every other
bulk operation (kill, pause, down, the up/create plan executor, logs,
ps, top, wait, restart, remove, images, model pulls, watch) launched
one goroutine per container/image/DAG-node with no cap at all.
Fix both via a shared newLimitedErrgroup helper applied at every
fan-out site, threading maxConcurrency through forEachContainerConcurrent
and ImagePruner, which had no access to composeService. Add a
regression test for the zero-value case.
service_containers.go's waitDependencies is intentionally left
unguarded: it's a per-dependency ticker poll, not a burst of engine
calls.
Signed-off-by: Guillaume Lours <[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.