Local Development

Why use Depot for local development?

Replacing docker build with depot build allows you to get faster Docker image builds via Depot's remote builders and persistent caching. The cache is shared across your entire team who has access to a given Depot project, allowing you to reuse build results and cache across your entire team for faster local development. Additionally, routing the image build to remote builders frees your local machine's CPU and memory resources.

Cache sharing with local builds

There is nothing additional you need to configure to share your build cache across your team for local builds. If your team members can access the Depot project, they will automatically share the same build cache. So, if you build an image locally, your team members can reuse the layers you built in their own builds.

How to use Depot for local development

To leverage Depot locally, install the depot CLI tool locally and configure your Depot project, if you haven't already.

With those two things complete, you can then login to Depot via the CLI:

depot login

Once you're logged in, you can configure Depot inside of your git repository by running the init command:

depot init

The init command writes a depot.json file to the root of your repository with the Depot project ID that you selected. Alternatively, you can skip the init command if you'd like and use the --project flag on the build command to specify the project ID.

You can now run a build with Depot locally by running the build command:

depot build -t my-image:latest .

By default, Depot won't return you the built image locally. Instead, the built image and the layers produced will remain in the build cache. However, if you'd like to download the image locally, for instance, so you can docker run it, you can specify the --load flag:

depot build -t my-image:latest --load .

Using Depot with Docker Compose

If you're using Docker Compose, you can configure your docker-compose.yml file just as you usually would. You can then build your images inside of a compose file via our bake command:

depot bake -f docker-compose.yml --load

The bake command concurrently builds all of the images defined in your compose file on a Depot builder with persistent caching. After the build, the --load flag will download the images locally. Once the build is complete, you can run your compose file as you usually would:

depot bake -f docker-compose.yml --load && docker compose up

The bake command effectively replaces docker compose build with depot bake and allows you to get significantly faster image builds while still being able to leverage Docker Compose.