1 files changed, 81 insertions, 0 deletions
diff --git a/middleware/federation/setup.go b/middleware/federation/setup.go
new file mode 100644
index 000000000..9a60fcc3d
--- /dev/null
+++ b/middleware/federation/setup.go
@@ -0,0 +1,81 @@
+package federation
+
+import (
+	"fmt"
+
+	"github.com/coredns/coredns/core/dnsserver"
+	"github.com/coredns/coredns/middleware"
+	"github.com/coredns/coredns/middleware/kubernetes"
+	"github.com/miekg/dns"
+
+	"github.com/mholt/caddy"
+)
+
+func init() {
+	caddy.RegisterPlugin("federation", caddy.Plugin{
+		ServerType: "dns",
+		Action:     setup,
+	})
+}
+
+func setup(c *caddy.Controller) error {
+	fed, err := federationParse(c)
+	if err != nil {
+		return middleware.Error("federation", err)
+	}
+
+	// Do this in OnStartup, so all middleware has been initialized.
+	c.OnStartup(func() error {
+		m := dnsserver.GetConfig(c).GetHandler("kubernetes")
+		if m == nil {
+			return nil
+		}
+		if x, ok := m.(kubernetes.Kubernetes); ok {
+			fed.Federations = x.Federations
+		}
+		return nil
+	})
+
+	dnsserver.GetConfig(c).AddMiddleware(func(next middleware.Handler) middleware.Handler {
+		fed.Next = next
+		return nil
+	})
+
+	return nil
+}
+
+func federationParse(c *caddy.Controller) (*Federation, error) {
+	fed := New()
+
+	for c.Next() {
+		// federation [zones..]
+		origins := make([]string, len(c.ServerBlockKeys))
+		copy(origins, c.ServerBlockKeys)
+
+		for c.NextBlock() {
+			x := c.Val()
+			switch c.Val() {
+			default:
+				args := c.RemainingArgs()
+				if len(args) != 1 {
+					return fed, fmt.Errorf("need two arguments for federation: %q", args)
+				}
+				fed.f[x] = dns.Fqdn(args[0])
+			}
+		}
+
+		for i := range origins {
+			origins[i] = middleware.Host(origins[i]).Normalize()
+		}
+
+		fed.zones = origins
+
+		if len(fed.f) == 0 {
+			return fed, fmt.Errorf("at least one name to zone federation expected")
+		}
+
+		return fed, nil
+	}
+
+	return fed, nil
+}