105a7c5b70
This approach mimics Tilt's behavior[^1]:
1. At sync time, `stat` the path on host
2. If the path does not exist -> `rm` from container
3. If the path exists -> sync to container
By handling things this way, we're always syncing based on the true
state, regardless of what's happened in the interim. For example, a
common pattern in POSIX tools is to create a file and then rename it
over an existing file. Based on timing, this could be a sync, delete,
sync (every file gets seen & processed) OR a delete, sync (by the
the time we process the event, the "temp" file is already gone, so
we just delete it from the container, where it never existed, but
that's fine since we deletes are idempotent thanks to the `-f` flag
on `rm`).
Additionally, when syncing, if the `stat` call shows it's for a
directory, we ignore it. Otherwise, duplicate, nested copies of the
entire path could get synced in. (On some OSes, an event for the
directory gets dispatched when a file inside of it is modified. In
practice, I think we might want this pushed further down in the
watching code, but since we're already `stat`ing the paths here now,
it's a good place to handle it.)
Lastly, there's some very light changes to the text when it does a
full rebuild that will list out the (merged) set of paths that
triggered it. We can continue to improve the output, but this is
really helpful for understanding why it's rebuilding.
[^1]: db7f887b06/internal/controllers/core/liveupdate/reconciler.go (L911)
Signed-off-by: Milas Bowman <milas.bowman@docker.com>
Table of Contents
- Docker Compose v2
- About update and backward compatibility
- Where to get Docker Compose
- Quick Start
- Contributing
Docker Compose v2
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.
About update and backward compatibility
Docker Compose V2 is a major version bump release of Docker Compose. It has been completely rewritten from scratch in Golang (V1 was in Python). The installation instructions for Compose V2 differ from V1. V2 is not a standalone binary anymore, and installation scripts will have to be adjusted. Some commands are different.
For a smooth transition from legacy docker-compose 1.xx, please consider installing compose-switch to translate docker-compose ... commands into Compose V2's docker compose .... . Also check V2's --compatibility flag.
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
docker-compose.ymlso 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.