plugin/errors: 'consolidate' option (#2192)

- see more details at https://github.com/infobloxopen/coredns-plugin-errors/pull/3

plugin/errors/setup.go

@@ -1,7 +1,8 @@
 package errors
 
 import (
-	"fmt"
+	"regexp"
+	"time"
 
 	"github.com/coredns/coredns/core/dnsserver"
 	"github.com/coredns/coredns/plugin"
@@ -22,6 +23,11 @@ func setup(c *caddy.Controller) error {
 		return plugin.Error("errors", err)
 	}
 
+	c.OnShutdown(func() error {
+		handler.stop()
+		return nil
+	})
+
 	dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
 		handler.Next = next
 		return handler
@@ -30,13 +36,13 @@ func setup(c *caddy.Controller) error {
 	return nil
 }
 
-func errorsParse(c *caddy.Controller) (errorHandler, error) {
-	handler := errorHandler{}
+func errorsParse(c *caddy.Controller) (*errorHandler, error) {
+	handler := newErrorHandler()
 
 	i := 0
 	for c.Next() {
 		if i > 0 {
-			return handler, plugin.ErrOnce
+			return nil, plugin.ErrOnce
 		}
 		i++
 
@@ -45,11 +51,39 @@ func errorsParse(c *caddy.Controller) (errorHandler, error) {
 		case 0:
 		case 1:
 			if args[0] != "stdout" {
-				return handler, fmt.Errorf("invalid log file: %s", args[0])
+				return nil, c.Errf("invalid log file: %s", args[0])
 			}
 		default:
-			return handler, c.ArgErr()
+			return nil, c.ArgErr()
+		}
+
+		for c.NextBlock() {
+			if err := parseBlock(c, handler); err != nil {
+				return nil, err
+			}
 		}
 	}
 	return handler, nil
 }
+
+func parseBlock(c *caddy.Controller, h *errorHandler) error {
+	if c.Val() != "consolidate" {
+		return c.SyntaxErr("consolidate")
+	}
+
+	args := c.RemainingArgs()
+	if len(args) != 2 {
+		return c.ArgErr()
+	}
+	p, err := time.ParseDuration(args[0])
+	if err != nil {
+		return c.Err(err.Error())
+	}
+	re, err := regexp.Compile(args[1])
+	if err != nil {
+		return c.Err(err.Error())
+	}
+	h.patterns = append(h.patterns, &pattern{period: p, pattern: re})
+
+	return nil
+}