Method discoverMembers

kv/memberlist/memberlist_client.go:926–950

Provides a dns-based member discovery to join a memberlist cluster w/o knowning members' addresses upfront. May both return some addresses and an error in case of a partial resolution.

(ctx context.Context, members []string)

// Provides a dns-based member discovery to join a memberlist cluster w/o knowning members' addresses upfront.
// May both return some addresses and an error in case of a partial resolution.
func (m *KV) discoverMembers(ctx context.Context, members []string) ([]string, error) {
	if len(members) == 0 {
		return nil, nil
	}

	var ms, resolve []string

	for _, member := range members {
		if strings.Contains(member, "+") {
			resolve = append(resolve, member)
		} else {
			// No DNS SRV record to lookup, just append member
			ms = append(ms, member)
		}
	}

	err := m.provider.Resolve(ctx, resolve)
	if err != nil {
		level.Warn(m.logger).Log("msg", "failed to resolve members", "addrs", strings.Join(resolve, ","), "err", err)
	}

	ms = append(ms, m.provider.Addresses()...)

	return ms, err
}

// Like discoverMembers() but retries (up to 10 times) on error.
func (m *KV) discoverMembersWithRetries(ctx context.Context, members []string) ([]string, error) {