nexarch/cmd/account-api/dbstart.go

package main

import (
	"context"
	"errors"
	"fmt"
	"time"

	"github.com/jackc/pgx/v5/pgconn"
)

const exitPermanentDBError = 2

type pinger interface {
	Ping(ctx context.Context) error
}

func isPermanentDBError(err error) bool {
	var pgErr *pgconn.PgError
	if !errors.As(err, &pgErr) {
		return false
	}
	switch pgErr.Code {
	case "28000", "28P01", "3D000":
		return true
	}
	return false
}

func waitForDB(ctx context.Context, p pinger, timeout time.Duration, sleep func(time.Duration)) error {
	deadline := time.Now().Add(timeout)
	delay := time.Second
	for {
		err := p.Ping(ctx)
		if err == nil {
			return nil
		}
		if isPermanentDBError(err) {
			return fmt.Errorf("datenbank lehnt Anmeldung oder Datenbank ab (dauerhaft): %w", err)
		}
		if time.Now().Add(delay).After(deadline) {
			return fmt.Errorf("datenbank nach %s nicht erreichbar: %w", timeout, err)
		}
		sleep(delay)
		if delay < 30*time.Second {
			delay *= 2
		}
	}
}