Backend e2e tests (and, more rarely, service startup) intermittently
failed applying migrations with `driver: bad connection`: a freshly
started Postgres — notably a test container — can reset a pooled
connection moments after it reports ready, killing the migration
transaction. The harness already waits for the double "ready" log and
pings before migrating, yet goose can still draw a connection postgres
then resets.
ApplyMigrations now wraps the schema-create + goose run in a bounded
retry that fires only on transient connection errors (driver.ErrBadConn
and the connection-failure messages Postgres drivers surface); both
steps are idempotent, so a retry resumes cleanly. Deterministic SQL
errors still fail fast.
Fixes the intermittent TestDiplomailAsyncFallbackOnUnsupportedPair (and
the eight other testcontainer e2e harnesses that share ApplyMigrations).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Ilia Denisov