Guillaume Lours
bbec45855a
On top of the output-tail infrastructure from the previous commit: Stderr bias: split the combined output tail into separate stdout and stderr buffers. stdcopy.StdCopy(wOut, wErr, reader) now routes each stream to its own outputTail. The error message prefers stderr (where hooks write their actual error) and falls back to stdout when stderr is empty: db hook exited with status 1: Table 'service.sites' doesn't exist A new hookExitError helper encapsulates this preference. pre_start parity: streamPreStartLogs previously short-circuited and returned immediately when listener was nil (detached mode / compose up -d), leaving the tail buffers empty and failure errors without context. The log stream is now always opened. The demultiplexed streams fill separate tailOut / tailErr buffers. On non-zero exit the stderr-biased tail is appended to the error (same behaviour as exec hooks). Tests: - TestRunHook_StderrBias: stdout noise stays out of the error when stderr has content. - TestPreStart_DetachedModeAttachesLogs: ContainerLogs is called even with a nil listener. - TestPreStart_FailureIncludesTail: a failing pre_start hook carries its stderr output in the returned error. 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.