MustTestInstance is NewTestInstance, except it prints errors to stderr and calls os.Exit when finished.

NewFromEnv sets up the database connections using the configuration in the process's environment variables.

NewTestInstance creates a new Docker-based database instance.

ApproxTime is a compare helper for clock skew.

ErrAlreadyLocked is returned if the lock is already in use.

ErrKeyConflict indicates that there was a key conflict inserting a row.

ErrNotFound indicates that the requested record was not found in the database.

TestInstance is a wrapper around the Docker-based database instance.

UnlockFn can be deferred to release a lock.