The Compose cap set is `cap_drop: ALL` plus CHOWN/SETGID/SETUID/DAC_OVERRIDE
and carries no FOWNER, and searxng's own entrypoint chowns /etc/searxng to
searxng:searxng, so every retained settings file belongs to that user by the
second boot. Chowning the temporary file first left root unable to chmod it,
so the migration exited 1 and `set -eu` killed the container before
`exec /usr/local/searxng/entrypoint.sh` — SearXNG never started and odysseus
blocked on its healthcheck.
Swap the two calls so the chmod lands while the temporary file is still
root-owned, and cover the ordering with a test that refuses the chmod once
the chown has happened, the way the kernel does.
Léo
54d794e8de