mhoennigandClaude Opus 5
eee4d5184c
werkator build succeeded after 00:03
PUT /containers/{id}/archive was the last endpoint Testcontainers asks
for that werkdock answered with a 501. It is what withCopyFileToContainer
sends, and with it an image's own init mechanism works: a script copied
to /docker-entrypoint-initdb.d is run by the postgres entrypoint.
Docker unpacks the tar into the container's writable layer. Werkdock has
none, and its rootfs is the image's own directory in the store, shared by
every instance and bound read-only — unpacking there would change the
image for everyone. So the tar goes into the instance directory and is
bound into the sandbox, one of two ways, and the image decides which:
whole where the image has nothing at the destination, file by file where
it has something, so its own files stay visible beside the copied ones.
That is docker's merge semantics, reached by another road.
The real client corrected the design once: Testcontainers sends path=/
and carries the whole path in the tar entry names. An afternoon's
assumption that / should be refused would have refused every copy there
is. The measured call is now written down in docs/testcontainers-api.md,
where the guesses can be checked against it.
Refused rather than ignored: a copy into a running instance (mounts are
fixed at start), a directory onto one the image fills (the bind would
hide it), symlinks and device nodes, entries that climb out of the
destination, and archives above 64 entries.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>