| name | ignore-sync |
| description | Mirror .gitignore to .dockerignore. Use whenever a .gitignore entry is added or removed, or when auditing a bloated Docker build context. |
Ignore Sync
.dockerignore does not inherit from .gitignore. Anything git ignores but .dockerignore misses still enters the Docker build context (COPY . . in the prepare stage of web/next/Dockerfile and api/hono/Dockerfile), and on this repo that has meant gigabytes: web/next/.next alone hit 3GB, .turbo 23GB.
Rule: the files are MIRRORS
.gitignore is the source of truth; .dockerignore follows it. The two files are byte-identical except one line: the platform-tail label (# git overrides vs # docker overrides). Every ignore rule AND every shared ! un-ignore (e.g. !.yarn/patches) lives in the shared body: same entry, same section, same order, in both files, in the same commit.
The one sanctioned divergence is the labeled platform tail at the end of each file, for a git-only or docker-only override. Today both tails carry only !.env.example under their respective label.
.env stays out of the context
Real .env* files never enter the Docker context. Each build mounts the host file as a required BuildKit secret (--mount=type=secret,id=dotenv,target=/app/.env,required=true; compose supplies it via secrets.dotenv.file: .env), so it bypasses the context, is validated in full during the build, and never lands in a layer. If a diff re-includes .env* to feed a builder-stage COPY, that is drift; sync it away.
Audit
diff -u .gitignore .dockerignore
Done when the ONLY difference is the tail label:
-# git overrides
+# docker overrides
Any other line is a missing sync.
