Docker Layer Caching (DLC) can reduce Docker image build times on CircleCI. Some frequently asked questions around DLC are:
Is DLC available between different workflows under the same project?
Yes, DLC is not locked to workflows or jobs. You can create a maximum of 50 DLC volumes per project.
Why are subsequent builds not able to access the cache consistently?
If a job fails while calling a specific DLC volume, it would require rebuilding when calling it again, causing inconsistencies. It is worth noting that different jobs may also use different volumes. An example being if two
machine jobs are run in parallel, they will get different DLC volumes.
Is DLC guaranteed?
Unfortunately, DLC is not guaranteed. If you are experiencing issues with cache-misses or need high-parallelism, consider trying the experimental cci-x/docker-registry-image-cache orb.
As an admin, can I see the content of a DLC volume?
While you can see what volume is used for each job, at this time, the content is unavailable.