func()

in internal/cloudsql/resolver.go [100:135]

• 22 lines of code
• 5 McCabe index (conditional complexity)

func (r *DNSInstanceConnectionNameResolver) queryDNS(ctx context.Context, domainName string) (instance.ConnName, error) {
	// Attempt to query the TXT records.
	// This could return a partial error where both err != nil && len(records) > 0.
	records, err := r.dnsResolver.LookupTXT(ctx, domainName)
	// If resolve failed and no records were found, return the error.
	if err != nil {
		return instance.ConnName{}, fmt.Errorf("unable to resolve TXT record for %q: %v", domainName, err)
	}

	// Process the records returning the first valid TXT record.

	// Sort the TXT record values alphabetically by instance name
	sort.Slice(records, func(i, j int) bool {
		return records[i] < records[j]
	})

	var perr error
	// Attempt to parse records, returning the first valid record.
	for _, record := range records {
		// Parse the target as a CN
		cn, parseErr := instance.ParseConnNameWithDomainName(record, domainName)
		if parseErr != nil {
			perr = fmt.Errorf("unable to parse TXT for %q -> %q : %v", domainName, record, parseErr)
			continue
		}
		return cn, nil
	}

	// If all the records failed to parse, return one of the parse errors
	if perr != nil {
		return instance.ConnName{}, perr
	}

	// No records were found, return an error.
	return instance.ConnName{}, fmt.Errorf("no valid TXT records found for %q", domainName)
}