os.Chmod(path, 0600) fails inside rootless podman containers because
fchmod is denied in the user namespace. This was fatal — the database
wouldn't open, crashing the service.
Changed to best-effort: log nothing on failure, database functions
correctly without the permission tightening. The file is already
protected by the container's volume mount and the host filesystem
permissions.
Root cause of the 2026-04-03 incident recovery failure — MCR and
Metacrypt couldn't start until their databases were deleted and
recreated.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Go's database/sql opens multiple connections by default, but SQLite
only supports one concurrent writer. Under concurrent load (e.g.
parallel blob uploads to MCR), multiple connections compete for the
write lock and exceed busy_timeout, causing transient 500 errors.
With WAL mode, a single connection still allows concurrent reads
from other processes. Go serializes access through the connection
pool, eliminating busy errors entirely.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
