centersl/docker-docs
1
0
Fork 0
mirror of https://github.com/docker/docs.git synced 2026-03-27 14:28:47 +07:00
Code Issues Packages Projects Releases Wiki Activity

build: WORKDIR+SOURCE_DATE_EPOCH cache invalidation

Browse Source 
Signed-off-by: David Karlsson <35727626+dvdksn@users.noreply.github.com>
This commit is contained in:
David Karlsson
2025-12-02 12:08:44 +01:00
parent e6879b9b94
commit 4865382560
1 changed files with 17 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
content/manuals/build/cache/invalidation.md vendored
View File

@@ -44,6 +44,23 @@ If your build contains several layers and you want to ensure the build cache is
reusable, order the instructions from less frequently changed to more
frequently changed where possible.
## WORKDIR and SOURCE_DATE_EPOCH
The `WORKDIR` instruction respects the `SOURCE_DATE_EPOCH` build argument when
determining cache validity. Changing `SOURCE_DATE_EPOCH` between builds
invalidates the cache for `WORKDIR` and all subsequent instructions.
`SOURCE_DATE_EPOCH` sets timestamps for files created during the build. If you
set this to a dynamic value like a Git commit timestamp, the cache breaks with
each commit. This is expected behavior when tracking build provenance.
For reproducible builds without frequent cache invalidation, use a fixed
timestamp:
```console
$ docker build --build-arg SOURCE_DATE_EPOCH=0 .
```
## RUN instructions
The cache for `RUN` instructions isn't invalidated automatically between builds.