Docker Layer Caching (DLC)

Docker Layer Caching (DLC) can help to reduce the time when you build a container image. All type of accounts except on free tier, gets layer caching enabled in your pipelines.

Overview

A Docker Image consists of layers which are mainly added when you execute RUN, ADD or COPY from Dockerfile. Each command creates a new layer that contains filesystem changes done by the command. Docker uses a layer cache to optimize the process of building Docker images and make it faster.

When none of the layers in the image change between workflow runs, DLC pulls the layers from cache from the image that was built previously and reuses those instead of rebuilding the entire image.

How it works with Daemon

A DLC volume is provisioned and transparetly attached to the Docker daemon on each workflow run. After the completion of a workflow run, the DLC volume is detached and can be re-used for future runs. The layers, generated during the workflow execution, are cached and kept inside the DLC volume. A DLC volume is not shared between multiple Docker Daemons if muliple workflows are running concurrently.

if your Dockerfile and related files haven't changed, a rebuild can reuse the existing layers in attached DLC volume.

Usage limits

The maximum number of DLC volumes allowed is 10 and storage size to be 10GB. If size of a DLC volume crosses 10GB, we will automatically grabage collect it. If you want to increase this quota, please contact our support.