func()

in pkg/dns/dns.go [676:728]

• 36 lines of code
• 8 McCabe index (conditional complexity)

func (kd *KubeDNS) recordsForFederation(records []skymsg.Service, path []string, exact bool, federationSegments []string) (retval []skymsg.Service, err error) {
	// For federation query, verify that the local service has endpoints.
	validRecord := false
	// isHeadlessServiceRecord and serviceWithClusterIPHasEndpoints assume
	// they have cacheLock.
	kd.cacheLock.RLock()
	for _, val := range records {
		// We know that a headless service has endpoints for sure if a
		// record was returned for it. The record contains endpoint
		// IPs. So nothing to check for headless services.
		if !kd.isHeadlessServiceRecord(&val) {
			ok, err := kd.serviceWithClusterIPHasEndpoints(&val)
			if err != nil {
				klog.V(3).Infof(
					"Federation: error finding if service has endpoint: %v", err)
				continue
			}
			if !ok {
				klog.V(3).Infof("Federation: skipping record since service has no endpoint: %v", val)
				continue
			}
		}
		validRecord = true
		break
	}
	kd.cacheLock.RUnlock()

	if validRecord {
		// There is a local service with valid endpoints, return its CNAME.
		name := strings.Join(util.ReverseArray(path), ".")
		// Ensure that this name that we are returning as a CNAME response
		// is a fully qualified domain name so that the client's resolver
		// library doesn't have to go through its search list all over
		// again.
		if !strings.HasSuffix(name, ".") {
			name = name + "."
		}
		klog.V(3).Infof(
			"Federation: Returning CNAME for local service: %v", name)
		return []skymsg.Service{{Host: name}}, nil
	}

	// If the name query is not an exact query and does not match any
	// records in the local store, attempt to send a federation redirect
	// (CNAME) response.
	if !exact {
		klog.V(3).Infof(
			"Federation: Did not find a local service. Trying federation redirect (CNAME)")
		return kd.federationRecords(util.ReverseArray(federationSegments))
	}

	return nil, etcd.Error{Code: etcd.ErrorCodeKeyNotFound}
}