Add secondary support

Allow specifying a primary server and retrieve the zone's content.

Add tests and an Expired bool to zone struct, to stop server zones

that are expired. The zone is retrieved on Startup, no updates of

changed content are done. We also don't respond to notifies yet.

core/directives.go

@@ -59,6 +59,7 @@ var directiveOrder = []directive{
 	{"errors", setup.Errors},
 
 	{"file", setup.File},
+	{"secondary", setup.Secondary},
 	{"etcd", setup.Etcd},
 	{"proxy", setup.Proxy},
 }

core/setup/file.go

@@ -36,9 +36,9 @@ func fileParse(c *Controller) (file.Zones, error) {
 			if c.NextArg() {
 				origin = c.Val()
 			}
-			// normalize this origin
-			origin = middleware.Host(origin).Standard()
+			origin = middleware.Host(origin).Normalize()
 
+			// TODO(miek): we should allow more. Issue #54.
 			reader, err := os.Open(fileName)
 			if err != nil {
 				return file.Zones{}, err
@@ -48,27 +48,40 @@ func fileParse(c *Controller) (file.Zones, error) {
 				z[origin] = zone
 			}
 			names = append(names, origin)
-			if c.NextBlock() {
-				what := c.Val()
-				if !c.NextArg() {
-					return file.Zones{}, c.ArgErr()
-				}
-				value := c.Val()
-				var err error
-				switch what {
-				case "transfer":
-					if value == "out" {
-						z[origin].Transfer.Out = true
-					}
-					if value == "in" {
-						z[origin].Transfer.In = true
-					}
-				}
-				if err != nil {
-					return file.Zones{}, err
+
+			for c.NextBlock() {
+				t, _, e := parseTransfer(c)
+				if e != nil {
+					return file.Zones{}, e
 				}
+				// discard from, here, maybe check and show log when we do?
+				z[origin].TransferTo = append(z[origin].TransferTo, t)
 			}
 		}
 	}
 	return file.Zones{Z: z, Names: names}, nil
 }
+
+// transfer to [address]
+func parseTransfer(c *Controller) (to, from string, err error) {
+	what := c.Val()
+	if !c.NextArg() {
+		return "", "", c.ArgErr()
+	}
+	value := c.Val()
+	switch what {
+	case "transfer":
+		if !c.NextArg() {
+			return "", "", c.ArgErr()
+		}
+		if value == "to" {
+			to = c.Val()
+			to = middleware.Addr(to).Normalize()
+		}
+		if value == "from" {
+			from = c.Val()
+			from = middleware.Addr(from).Normalize()
+		}
+	}
+	return
+}

core/setup/secondary.go

@@ -0,0 +1,59 @@
+package setup
+
+import (
+	"github.com/miekg/coredns/middleware"
+	"github.com/miekg/coredns/middleware/file"
+	"github.com/miekg/coredns/middleware/secondary"
+)
+
+// Secondary sets up the secondary middleware.
+func Secondary(c *Controller) (middleware.Middleware, error) {
+	zones, err := secondaryParse(c)
+	if err != nil {
+		return nil, err
+	}
+
+	// Setup retrieve the zone.
+	for _, n := range zones.Names {
+		if len(zones.Z[n].TransferFrom) > 0 {
+			c.Startup = append(c.Startup, func() error {
+				err := zones.Z[n].TransferIn()
+				return err
+			})
+		}
+	}
+
+	return func(next middleware.Handler) middleware.Handler {
+		return secondary.Secondary{file.File{Next: next, Zones: zones}}
+	}, nil
+
+}
+
+func secondaryParse(c *Controller) (file.Zones, error) {
+	z := make(map[string]*file.Zone)
+	names := []string{}
+	for c.Next() {
+		if c.Val() == "secondary" {
+			// secondary [origin]
+			origin := c.ServerBlockHosts[c.ServerBlockHostIndex]
+			if c.NextArg() {
+				origin = c.Val()
+			}
+			// TODO(miek): we should allow more. Issue #54.
+			origin = middleware.Host(origin).Normalize()
+
+			z[origin] = file.NewZone(origin)
+			names = append(names, origin)
+
+			for c.NextBlock() {
+				t, f, e := parseTransfer(c)
+				if e != nil {
+					return file.Zones{}, e
+				}
+				z[origin].TransferTo = append(z[origin].TransferTo, t)
+				z[origin].TransferFrom = append(z[origin].TransferFrom, f)
+			}
+		}
+	}
+	return file.Zones{Z: z, Names: names}, nil
+}