Merge pull request d2iq-archive#123 from mesosphere/soa

Improve customization of SOA records

config.json.sample

@@ -4,11 +4,17 @@
   "refreshSeconds": 60,
   "ttl": 60,
   "domain": "mesos",
+  "ns": "ns1",
   "port": 8053,
   "resolvers": ["8.8.8.8"],
   "timeout": 5,
   "listener": "0.0.0.0",
-  "email": "root.mesos-dns.mesos",
+  "SOAMname": "root.ns1.mesos",
+  "SOARname": "ns1.mesos",
+  "SOARefresh": 60,
+  "SOARetry":   600,
+  "SOAExpire":  86400,
+  "SOAMinttl": 60,
   "dnson": true,
   "httpon": true,
   "httpport": 8123,

docs/docs/configuration-parameters.md

@@ -18,8 +18,17 @@ The configuration file should include the following fields:
   "port": 53,
   "resolvers": ["169.254.169.254"],
   "timeout": 5, 
+  "httpon": true,
+  "dsnon": true,
+  "httpport": 8123,
+  "externalon": true
   "listener": "10.101.160.16",
-  "email": "root.mesos-dns.mesos"
+  "SOAMname": "root.ns1.mesos",
+  "SOARname": "ns1.mesos",
+  "SOARefresh": 60,
+  "SOARetry":   600,
+  "SOAExpire":  86400,
+  "SOAMinttl": 60,
 }
 ```
 
@@ -43,13 +52,21 @@ It is sufficient to specify just one of the `zk` or `masters` field. If both are
 
 `listener` is the IP address of Mesos-DNS. In SOA replies, Mesos-DNS identifies hostname `mesos-dns.domain` as the primary nameserver for the domain. It uses this IP address in an A record for `mesos-dns.domain`. The default value is "0.0.0.0", which instructs Mesos-DNS to create an A record for every IP address associated with a network interface on the server that runs the Mesos-DNS process. 
 
-`email` is the email address of the Mesos domain name administrator. It is associated with the SOA record for the Mesos domain. The format is `mailbox-name.domain`, using a `.` instead of `@`. For example, if the email address is `root@mesos-dns.mesos`, the `email` field should be `root.mesos-dns.mesos`. The default value is `root.mesos-dns.mesos`.
-
 `dnson` is a boolean field that controls whether Mesos-DNS listens for DNS requests or not. The default value is `true`. 
 
 `httpon` is a boolean field that controls whether Mesos-DNS listens for HTTP requests or not. The default value is `true`. 
 
 `httpport` is the port number that Mesos-DNS monitors for incoming HTTP requests. The default value is `8123`.
 
+`externalon` is a boolean field that controls whether Mesos-DNS serves requests outside of the Mesos domain. The default value is `true`. 
+
+`SOAMname` is the MNAME field in the SOA record for the Mesos domain. The format is `mailbox.domain`, using a `.` instead of `@`. For example, if the email address is `root@ns1.mesos`, the `email` field should be `root.mesos-dns.mesos`. For details, see the [RFC-1035](http://tools.ietf.org/html/rfc1035#page-18). The default value is `root.ns1.mesos`. 
+
+`SOARefresh` is the REFRESH field in the SOA record for the Mesos domain. For details, see the [RFC-1035](http://tools.ietf.org/html/rfc1035#page-18). The default value is `60`.
+
+`SOARetry` is the RETRY field in the SOA record for the Mesos domain. For details, see the [RFC-1035](http://tools.ietf.org/html/rfc1035#page-18). The default value is `600`.
+
+`SOAExpire` is the EXPIRE field in the SOA record for the Mesos domain. For details, see the [RFC-1035](http://tools.ietf.org/html/rfc1035#page-18). The default value is `86400`.
 
+`SOAMinttl` is the minimum TTL field in the SOA record for the Mesos domain. For details, see the [RFC-2308](https://tools.ietf.org/html/rfc2308). The default value is `60`.
 

docs/docs/faq.md

@@ -10,6 +10,13 @@ title: Mesos-DNS FAQ
 
 You can check the Mesos-DNS version by executing `mesos-dns -version`. 
 
+
+---
+
+#### SOA record customization
+
+You can customize all fields in the SOA records for the Mesos domain. See the `SOA*` [configuration parameters](configuration-parameters.html).
+
 ---
 
 #### Verbose and very verbose modes

records/config.go

@@ -8,6 +8,7 @@ import (
 	"os/user"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/mesosphere/mesos-dns/logging"
 	"github.com/miekg/dns"
@@ -26,7 +27,7 @@ type Config struct {
 	RefreshSeconds int
 
 	// TTL: the TTL value used for SRV and A records (default 60)
-	TTL int
+	TTL int32
 
 	// Resolver port: port used to listen for slave requests (default 53)
 	Port int
@@ -44,11 +45,14 @@ type Config struct {
 	// File is the location of the config.json file
 	File string
 
-	// Email is the rname for a SOA
-	Email string
-
-	// Mname is the mname for a SOA
-	Mname string
+	// SOA record fields (see http://tools.ietf.org/html/rfc1035#page-18)
+	SOAMname   string  // primary name server
+	SOARname   string  // email of admin esponsible 
+	SOASerial  uint32  // initial version number (incremented on refresh)
+	SOARefresh uint32  // refresh interval
+	SOARetry   uint32  // retry interval 
+	SOAExpire  uint32  // expiration time
+	SOAMinttl  uint32  // minimum TTL
 
 	// ListenAddr is the server listener address
 	Listener string
@@ -73,7 +77,12 @@ func SetConfig(cjson string) (c Config) {
 		Domain:         "mesos",
 		Port:           53,
 		Timeout:        5,
-		Email:          "root.mesos-dns.mesos",
+		SOARname:       "root.ns1.mesos",
+	        SOAMname:       "ns1.mesos",
+	        SOARefresh:     60,
+	        SOARetry:       600,
+	        SOAExpire:      86400,
+	        SOAMinttl:      60,
 		Resolvers:      []string{"8.8.8.8"},
 		Listener:       "0.0.0.0",
 		HttpPort:       8123,
@@ -119,14 +128,18 @@ func SetConfig(cjson string) (c Config) {
 		c.Resolvers = GetLocalDNS()
 	}
 
-	c.Email = strings.Replace(c.Email, "@", ".", -1)
-	if c.Email[len(c.Email)-1:] != "." {
-		c.Email = c.Email + "."
-	}
-
 	c.Domain = strings.ToLower(c.Domain)
-	c.Mname = "mesos-dns." + c.Domain + "."
 
+	// SOA record fields
+	c.SOARname = strings.Replace(c.SOARname, "@", ".", -1)
+	if c.SOARname[len(c.SOARname)-1:] != "." {
+		c.SOARname = c.SOARname + "."
+	}
+	if c.SOAMname[len(c.SOAMname)-1:] != "." {
+		c.SOAMname = c.SOAMname + "."
+	}
+	c.SOASerial = uint32(time.Now().Unix())
+
 	// print configuration file
 	logging.Verbose.Println("Mesos-DNS configuration:")
 	if len(c.Masters) != 0 {
@@ -144,8 +157,13 @@ func SetConfig(cjson string) (c Config) {
 	logging.Verbose.Println("   - Timeout: ", c.Timeout)
 	logging.Verbose.Println("   - Resolvers: " + strings.Join(c.Resolvers, ", "))
 	logging.Verbose.Println("   - ExternalOn: ", c.ExternalOn)
-	logging.Verbose.Println("   - Email: " + c.Email)
-	logging.Verbose.Println("   - Mname: " + c.Mname)
+	logging.Verbose.Println("   - SOAMname: " + c.SOAMname)
+	logging.Verbose.Println("   - SOARname: " + c.SOARname)
+	logging.Verbose.Println("   - SOASerial: ", c.SOASerial)
+	logging.Verbose.Println("   - SOARefresh: ", c.SOARefresh)
+	logging.Verbose.Println("   - SOARetry: ", c.SOARetry)
+	logging.Verbose.Println("   - SOAExpire: ", c.SOAExpire)
+	logging.Verbose.Println("   - SOAExpire: ", c.SOAMinttl)
 	logging.Verbose.Println("   - HttpPort: ", c.HttpPort)
 	logging.Verbose.Println("   - HttpOn: ", c.HttpOn)
 	logging.Verbose.Println("   - ConfigFile: ", c.File)

records/generator.go

@@ -80,7 +80,7 @@ func (rg *RecordGenerator) ParseState(leader string, c Config) error {
 	}
 
 	// insert state
-	rg.InsertState(sj, c.Domain, c.Mname, c.Listener, c.Masters)
+	rg.InsertState(sj, c.Domain, c.SOAMname, c.Listener, c.Masters)
 	return nil
 }
 
@@ -188,7 +188,7 @@ func (rg *RecordGenerator) loadWrap(ip string, port string) (StateJSON, error) {
 }
 
 // InsertState transforms a StateJSON into RecordGenerator RRs
-func (rg *RecordGenerator) InsertState(sj StateJSON, domain string, mname string,
+func (rg *RecordGenerator) InsertState(sj StateJSON, domain string, ns string,
 	listener string, masters []string) error {
 
 	// creates a map with slave IP addresses (IPv4)
@@ -244,7 +244,7 @@ func (rg *RecordGenerator) InsertState(sj StateJSON, domain string, mname string
 		}
 	}
 
-	rg.listenerRecord(listener, mname)
+	rg.listenerRecord(listener, ns)
 	rg.masterRecord(domain, masters, sj.Leader)
 	return nil
 }
@@ -294,20 +294,20 @@ func (rg *RecordGenerator) masterRecord(domain string, masters []string, leader
 }
 
 // A record for mesos-dns (the name is listed in SOA replies)
-func (rg *RecordGenerator) listenerRecord(listener string, mname string) {
+func (rg *RecordGenerator) listenerRecord(listener string, ns string) {
 	if listener == "0.0.0.0" {
-		rg.setFromLocal(listener, mname)
+		rg.setFromLocal(listener, ns)
 	} else if listener == "127.0.0.1" {
-		rg.insertRR(mname, "127.0.0.1", "A")
+		rg.insertRR(ns, "127.0.0.1", "A")
 	} else {
-		rg.insertRR(mname, listener, "A")
+		rg.insertRR(ns, listener, "A")
 	}
 }
 
 // A records for each local interface
 // If this causes problems you should explicitly set the
 // listener address in config.json
-func (rg *RecordGenerator) setFromLocal(host string, mname string) {
+func (rg *RecordGenerator) setFromLocal(host string, ns string) {
 
 	ifaces, err := net.Interfaces()
 	if err != nil {
@@ -340,7 +340,7 @@ func (rg *RecordGenerator) setFromLocal(host string, mname string) {
 				continue
 			}
 
-			rg.insertRR(mname, ip.String(), "A")
+			rg.insertRR(ns, ip.String(), "A")
 		}
 	}
 }

resolver/resolver.go

@@ -121,9 +121,11 @@ func (res *Resolver) Reload() {
 	err := t.ParseState(currentLeader, res.config)
 
 	if err == nil {
+		timestamp :=  uint32(time.Now().Unix())
 		// may need to refactor for fairness
 		res.rsLock.Lock()
 		defer res.rsLock.Unlock()
+		res.config.SOASerial = timestamp
 		res.rs = &t
 	} else {
 		logging.VeryVerbose.Println("Warning: master not found; keeping old DNS state")
@@ -225,12 +227,12 @@ func (res *Resolver) formatSOA(dom string) (*dns.SOA, error) {
 			Class:  dns.ClassINET,
 			Ttl:    ttl,
 		},
-		Ns:      res.config.Mname,
-		Mbox:    res.config.Email,
-		Serial:  uint32(time.Now().Unix()),
-		Refresh: ttl,
-		Retry:   600,
-		Expire:  86400,
+		Ns:      res.config.SOAMname,
+		Mbox:    res.config.SOARname,
+		Serial:  res.config.SOASerial,
+		Refresh: res.config.SOARefresh,
+		Retry:   res.config.SOARetry,
+		Expire:  res.config.SOAExpire,
 		Minttl:  ttl,
 	}, nil
 }
@@ -313,7 +315,7 @@ func (res *Resolver) HandleMesos(w dns.ResponseWriter, r *dns.Msg) {
 
 	m := new(dns.Msg)
 	m.Authoritative = true
-	m.RecursionAvailable = true
+	m.RecursionAvailable = false
 	m.SetReply(r)
 
 	rs := res.records()
@@ -385,7 +387,6 @@ func (res *Resolver) HandleMesos(w dns.ResponseWriter, r *dns.Msg) {
 	} else {
 		// no answers but not a {SOA,SRV} request
 		if len(m.Answer) == 0 && (qType != dns.TypeSOA) && (qType != dns.TypeSRV) {
-
 			m = new(dns.Msg)
 			// set NXDOMAIN
 			m.SetRcode(r, 3)

resolver/resolver_test.go

@@ -73,8 +73,8 @@ func fakeDNS(port int) (Resolver, error) {
 		Domain:    "mesos",
 		Resolvers: records.GetLocalDNS(),
 		Listener:  "127.0.0.1",
-		Email:     "root.mesos-dns.mesos.",
-		Mname:     "mesos-dns.mesos.",
+		SOARname:  "root.ns1.mesos.",
+		SOAMname:  "ns1.mesos.",
 		HttpPort:  8123,
 	        ExternalOn: true,
 	}