1 files changed, 84 insertions, 0 deletions
diff --git a/middleware/metrics/setup.go b/middleware/metrics/setup.go
new file mode 100644
index 000000000..f31cbd4d5
--- /dev/null
+++ b/middleware/metrics/setup.go
@@ -0,0 +1,84 @@
+package metrics
+
+import (
+	"sync"
+
+	"github.com/miekg/coredns/core/dnsserver"
+	"github.com/miekg/coredns/middleware"
+
+	"github.com/mholt/caddy"
+)
+
+func init() {
+	caddy.RegisterPlugin("prometheus", caddy.Plugin{
+		ServerType: "dns",
+		Action:     setup,
+	})
+}
+
+func setup(c *caddy.Controller) error {
+	m, err := prometheusParse(c)
+	if err != nil {
+		return err
+	}
+
+	dnsserver.GetConfig(c).AddMiddleware(func(next dnsserver.Handler) dnsserver.Handler {
+		m.Next = next
+		return m
+	})
+
+	metricsOnce.Do(func() {
+		c.OnStartup(m.Startup)
+		c.OnShutdown(m.Shutdown)
+	})
+
+	return nil
+}
+
+func prometheusParse(c *caddy.Controller) (Metrics, error) {
+	var (
+		met Metrics
+		err error
+	)
+
+	for c.Next() {
+		if len(met.ZoneNames) > 0 {
+			return Metrics{}, c.Err("metrics: can only have one metrics module per server")
+		}
+		met.ZoneNames = make([]string, len(c.ServerBlockKeys))
+		copy(met.ZoneNames, c.ServerBlockKeys)
+		for i, _ := range met.ZoneNames {
+			met.ZoneNames[i] = middleware.Host(met.ZoneNames[i]).Normalize()
+		}
+		args := c.RemainingArgs()
+
+		switch len(args) {
+		case 0:
+		case 1:
+			met.Addr = args[0]
+		default:
+			return Metrics{}, c.ArgErr()
+		}
+		for c.NextBlock() {
+			switch c.Val() {
+			case "address":
+				args = c.RemainingArgs()
+				if len(args) != 1 {
+					return Metrics{}, c.ArgErr()
+				}
+				met.Addr = args[0]
+			default:
+				return Metrics{}, c.Errf("metrics: unknown item: %s", c.Val())
+			}
+
+		}
+	}
+	if met.Addr == "" {
+		met.Addr = addr
+	}
+	return met, err
+}
+
+var metricsOnce sync.Once
+
+const addr = "localhost:9153"