// CreateInterface creates a clouddns.Interface object using the specified parameters.
// If no tokenSource is specified, uses oauth2.DefaultTokenSource.
func CreateInterface(projectID string, tokenSource oauth2.TokenSource) (*Interface, error) {
if tokenSource == nil {
var err error
tokenSource, err = google.DefaultTokenSource(
oauth2.NoContext,
compute.CloudPlatformScope,
compute.ComputeScope)
glog.Infof("Using DefaultTokenSource %#v", tokenSource)
if err != nil {
return nil, err
}
} else {
glog.Infof("Using existing Token Source %#v", tokenSource)
}
oauthClient := oauth2.NewClient(oauth2.NoContext, tokenSource)
service, err := dns.New(oauthClient)
if err != nil {
glog.Errorf("Failed to get Cloud DNS client: %v", err)
}
glog.Infof("Successfully got DNS service: %v\n", service)
return newInterfaceWithStub(projectID, internal.NewService(service)), nil
}
// Periodically populate DNS using the host-inventory:
func Updater(config *types.Config) {
// Run forever:
log.Infof("[dnsUpdater] Started")
for {
// Sleep until the next run:
log.Debugf("[dnsUpdater] Sleeping for %vs ...", config.DNSUpdateFrequency)
time.Sleep(time.Duration(config.DNSUpdateFrequency) * time.Second)
// Lock the host-list (so we don't try to access it when another go-routine is modifying it):
log.Tracef("[dnsUpdater] Trying to lock config.HostInventoryMutex ...")
config.HostInventoryMutex.Lock()
log.Tracef("[dnsUpdater] Locked config.HostInventoryMutex")
// See if we actually have any changes to make:
if len(config.HostInventory.Environments) > 0 {
// Connect to GCE (either from GCE permissions, JSON file, or ENV-vars):
client, err := google.DefaultClient(context.Background(), googledns.CloudPlatformScope)
if err != nil {
log.Errorf("[dnsUpdater] Unable to authenticate to GCE! (%s)", err)
continue
}
// Get a DNS service-object:
dnsService, err := googledns.New(client)
if err != nil {
log.Errorf("[dnsUpdater] Failed to connecting to GCE! %v", err)
continue
}
// Get the project:
googleComputeProject, err := metadata.ProjectID()
if err != nil {
log.Errorf("[hostInventoryUpdater] Unable to retrieve metadata from instance! (%s)", err)
continue
} else {
log.Debugf("[hostInventoryUpdater] Found project-id (%v)", googleComputeProject)
}
// Get a list of pre-existing DNS records in this zone:
resourceRecordSetsList, err := dnsService.ResourceRecordSets.List(googleComputeProject, config.DNSZoneName).Do()
if err != nil {
log.Errorf("[dnsUpdater] Unable to make DNS ResourceRecordSets.List() call! (%s)", err)
continue
} else {
log.Debugf("[dnsUpdater] Found %v pre-existing DNS records", len(resourceRecordSetsList.Rrsets))
}
// Go through each environment:
for environmentName, environment := range config.HostInventory.Environments {
// Prepare a "change" (which is a list of records to add):
change := &googledns.Change{
Additions: []*googledns.ResourceRecordSet{},
}
// See if we already have a DNS entry:
for _, resourceRecordSet := range resourceRecordSetsList.Rrsets {
record, ok := environment.DNSRecords[resourceRecordSet.Name]
if ok {
// See if the record needs to be deleted and changed:
if fmt.Sprintf("%v", record) == fmt.Sprintf("%v", resourceRecordSet.Rrdatas) {
// Delete the record from the host-inventory (to prevent it from being created again):
log.Debugf("[dnsUpdater] Record %v already exists in DNS (%v) - no need to make it again", resourceRecordSet.Name, record)
delete(environment.DNSRecords, resourceRecordSet.Name)
} else {
// The record doesn't match, so we'll ask for it to be deleted:
change.Deletions = append(change.Deletions, resourceRecordSet)
}
}
}
// Now iterate over the host-inventory:
log.Debugf("[dnsUpdater] Creating requests for the '%v' environment ...", environmentName)
for dnsRecordName, dnsRecordValue := range environment.DNSRecords {
// Prepare a resourceRecordSet:
log.Debugf("[dnsUpdater] Record: %v => %v", dnsRecordName, dnsRecordValue)
change.Additions = append(change.Additions, &googledns.ResourceRecordSet{
Name: dnsRecordName,
Rrdatas: dnsRecordValue,
Ttl: config.DNSTTL,
Type: "A",
})
}
// Make the Create() call:
if len(change.Additions) > 0 || len(change.Deletions) > 0 {
changeMade, err := dnsService.Changes.Create(googleComputeProject, config.DNSZoneName, change).Do()
if err != nil {
log.Errorf("[dnsUpdater] Unable to make DNS Changes.Create() call! (%s)", err)
continue
} else {
log.Debugf("[dnsUpdater] Made %v changes to DNS zone (%v), status: %v", len(changeMade.Additions), googleComputeProject, changeMade.Status)
}
} else {
log.Infof("[dnsUpdater] No changes to be made")
}
}
} else {
log.Info("[dnsUpdater] No DNS changes to make")
}
// Unlock the host-inventory:
log.Tracef("[dnsUpdater] Unlocking config.HostInventoryMutex ...")
config.HostInventoryMutex.Unlock()
}
}
