// Lookup the Route53 zone-id for the domain-name we were given:
func getRoute53ZoneId(domainName string) (string, error) {
// Authenticate with AWS:
awsAuth, err := aws.GetAuth("", "", "", time.Now())
if err != nil {
log.Criticalf("[dnsUpdater] Unable to authenticate to AWS! (%s)", err)
return "", err
} else {
log.Debugf("[dnsUpdater] Authenticated to AWS")
}
// Make a new EC2 connection:
log.Debugf("[dnsUpdater] Connecting to Route53 ...")
route53Connection, err := route53.NewRoute53(awsAuth)
if err != nil {
log.Criticalf("[dnsUpdater] Unable to connect to Route53! (%s)", err)
return "", err
}
// Submit the request:
ListHostedZonesResponse, err := route53Connection.ListHostedZones("", 100)
if err != nil {
log.Criticalf("[dnsUpdater] Failed to make ListHostedZones call: %v", err)
return "", err
} else {
log.Debugf("[dnsUpdater] Retreived %d DNS zones.", len(ListHostedZonesResponse.HostedZones))
}
// Go through the responses looking for our zone:
for _, hostedZone := range ListHostedZonesResponse.HostedZones {
// Compare the name to the one provided:
if hostedZone.Name == domainName {
log.Infof("[dnsUpdater] Found ID (%v) for domain (%v).", hostedZone.Id, domainName)
// Split the zone-ID (because they tend to look like "/hostedzone/ZXJHAS123"):
return strings.Split(hostedZone.Id, "/")[2], nil
break
}
}
log.Criticalf("[dnsUpdater] Couldn't find zone-ID for domain (%v)!", domainName)
os.Exit(1)
return "", errors.New(fmt.Sprintf("Couldn't find DNS-domain '%v' on your AWS account", domainName))
}
// Periodically populate DNS using the host-inventory:
func Updater(config *types.Config) {
// Get the Route53 "Zone-ID":
route53zoneId, err := getRoute53ZoneId(config.DNSDomainName)
if err != nil {
log.Criticalf("Error looking up DNS zone-id: %v", err)
os.Exit(2)
}
// 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 {
// Authenticate with AWS:
awsAuth, err := aws.GetAuth("", "", "", time.Now())
if err != nil {
log.Errorf("[dnsUpdater] Unable to authenticate to AWS! (%s)", err)
continue
} else {
log.Debugf("[dnsUpdater] Authenticated to AWS")
}
// Make a new EC2 connection:
log.Debugf("[dnsUpdater] Connecting to Route53 ...")
route53Connection, err := route53.NewRoute53(awsAuth)
if err != nil {
log.Errorf("[dnsUpdater] Unable to connect to Route53! (%s)", err)
continue
}
// Go through each environment:
for environmentName, environment := range config.HostInventory.Environments {
// Make an empty batch of changes:
changes := make([]route53.ResourceRecordSet, 0)
// Now iterate over the host-inventory:
log.Debugf("[dnsUpdater] Creating requests for the '%v' environment ...", environmentName)
for dnsRecordName, dnsRecordValue := range environment.DNSRecords {
// Turn the list of strings (host-addresses) into a list of route53.ResourceRecordValue:
resourceRecordValues := make([]route53.ResourceRecordValue, 0)
for _, hostAddress := range dnsRecordValue {
resourceRecordValues = append(resourceRecordValues, route53.ResourceRecordValue{Value: hostAddress})
}
// Prepare a change-request:
log.Debugf("[dnsUpdater] Record: %v => %v", dnsRecordName, dnsRecordValue)
changes = append(changes, &route53.BasicResourceRecordSet{
Action: "UPSERT",
Name: dnsRecordName,
Type: "A",
TTL: config.DNSTTL,
Values: resourceRecordValues,
})
}
// Create a request to modify records:
changeResourceRecordSetsRequest := route53.ChangeResourceRecordSetsRequest{
Xmlns: "https://route53.amazonaws.com/doc/2013-04-01/",
Changes: changes,
}
// Submit the request:
changeResourceRecordSetsResponse, err := route53Connection.ChangeResourceRecordSet(&changeResourceRecordSetsRequest, route53zoneId)
if err != nil {
log.Errorf("[dnsUpdater] Failed to make changeResourceRecordSetsResponse call: %v", err)
continue
} else {
log.Infof("[dnsUpdater] Successfully updated %d DNS record-sets for %v.%v (Request-ID: %v, Status: %v, Submitted: %v)", len(changes), environmentName, config.DNSDomainName, changeResourceRecordSetsResponse.Id, changeResourceRecordSetsResponse.Status, changeResourceRecordSetsResponse.SubmittedAt)
}
}
} else {
log.Info("[dnsUpdater] No DNS changes to make")
}
// Unlock the host-inventory:
log.Tracef("[dnsUpdater] Unlocking config.HostInventoryMutex ...")
config.HostInventoryMutex.Unlock()
}
}