add configurable log level to errors plugin (#4718)

Automatically submitted.

plugin/errors/README.md

@@ -22,12 +22,12 @@ Extra knobs are available with an expanded syntax:
 
 ~~~
 errors {
-	consolidate DURATION REGEXP
+	consolidate DURATION REGEXP [LEVEL]
 }
 ~~~
 
-Option `consolidate` allows collecting several error messages matching the regular expression **REGEXP** during **DURATION**. After the **DURATION** since receiving the first such message, the consolidated message will be printed to standard output, e.g.
-
+Option `consolidate` allows collecting several error messages matching the regular expression **REGEXP** during **DURATION**. After the **DURATION** since receiving the first such message, the consolidated message will be printed to standard output with
+log level, which is configurable by optional option **LEVEL**. Supported options for **LEVEL** option are `warn`,`error`,`info` and `debug`.
 ~~~
 2 errors like '^read udp .* i/o timeout$' occurred in last 30s
 ~~~
@@ -53,7 +53,7 @@ Use the *forward* to resolve queries via 8.8.8.8 and print consolidated error me
 . {
     forward . 8.8.8.8
     errors {
-        consolidate 5m ".* i/o timeout$"
+        consolidate 5m ".* i/o timeout$" warn
         consolidate 30s "^Failed to .+"
     }
 }

plugin/errors/errors.go

@@ -22,6 +22,7 @@ type pattern struct {
 	count       uint32
 	period      time.Duration
 	pattern     *regexp.Regexp
+	logCallback func(format string, v ...interface{})
 }
 
 func (p *pattern) timer() *time.Timer {
@@ -46,7 +47,7 @@ func newErrorHandler() *errorHandler {
 func (h *errorHandler) logPattern(i int) {
 	cnt := atomic.SwapUint32(&h.patterns[i].count, 0)
 	if cnt > 0 {
-		log.Errorf("%d errors like '%s' occurred in last %s",
+		h.patterns[i].logCallback("%d errors like '%s' occurred in last %s",
 			cnt, h.patterns[i].pattern.String(), h.patterns[i].period)
 	}
 }

plugin/errors/errors_test.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/coredns/coredns/plugin"
 	"github.com/coredns/coredns/plugin/pkg/dnstest"
+	clog "github.com/coredns/coredns/plugin/pkg/log"
 	"github.com/coredns/coredns/plugin/test"
 
 	"github.com/miekg/dns"
@@ -71,7 +72,40 @@ func TestErrors(t *testing.T) {
 }
 
 func TestLogPattern(t *testing.T) {
+	type args struct {
+		logCallback func(format string, v ...interface{})
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "error log",
+			args: args{logCallback: log.Errorf},
+			want: "[ERROR] plugin/errors: 4 errors like '^error.*!$' occurred in last 2s",
+		},
+		{
+			name: "warn log",
+			args: args{logCallback: log.Warningf},
+			want: "[WARNING] plugin/errors: 4 errors like '^error.*!$' occurred in last 2s",
+		},
+		{
+			name: "info log",
+			args: args{logCallback: log.Infof},
+			want: "[INFO] plugin/errors: 4 errors like '^error.*!$' occurred in last 2s",
+		},
+		{
+			name: "debug log",
+			args: args{logCallback: log.Debugf},
+			want: "[DEBUG] plugin/errors: 4 errors like '^error.*!$' occurred in last 2s",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
 			buf := bytes.Buffer{}
+			clog.D.Set()
 			golog.SetOutput(&buf)
 
 			h := &errorHandler{
@@ -79,13 +113,15 @@ func TestLogPattern(t *testing.T) {
 					count:       4,
 					period:      2 * time.Second,
 					pattern:     regexp.MustCompile("^error.*!$"),
+					logCallback: tt.args.logCallback,
 				}},
 			}
 			h.logPattern(0)
 
-	expLog := "4 errors like '^error.*!$' occurred in last 2s"
-	if log := buf.String(); !strings.Contains(log, expLog) {
-		t.Errorf("Expected log %q, but got %q", expLog, log)
+			if log := buf.String(); !strings.Contains(log, tt.want) {
+				t.Errorf("Expected log %q, but got %q", tt.want, log)
+			}
+		})
 	}
 }
 
@@ -154,6 +190,7 @@ func TestStop(t *testing.T) {
 		patterns: []*pattern{{
 			period:  2 * time.Second,
 			pattern: regexp.MustCompile("^error.*!$"),
+			logCallback: log.Errorf,
 		}},
 	}
 

plugin/errors/setup.go

@@ -66,7 +66,7 @@ func parseBlock(c *caddy.Controller, h *errorHandler) error {
 	}
 
 	args := c.RemainingArgs()
-	if len(args) != 2 {
+	if len(args) < 2 || len(args) > 3 {
 		return c.ArgErr()
 	}
 	p, err := time.ParseDuration(args[0])
@@ -77,7 +77,30 @@ func parseBlock(c *caddy.Controller, h *errorHandler) error {
 	if err != nil {
 		return c.Err(err.Error())
 	}
-	h.patterns = append(h.patterns, &pattern{period: p, pattern: re})
+	lc, err := parseLogLevel(c, args)
+	if err != nil {
+		return err
+	}
+	h.patterns = append(h.patterns, &pattern{period: p, pattern: re, logCallback: lc})
 
 	return nil
 }
+
+func parseLogLevel(c *caddy.Controller, args []string) (func(format string, v ...interface{}), error) {
+	if len(args) != 3 {
+		return log.Errorf, nil
+	}
+
+	switch args[2] {
+	case "warn":
+		return log.Warningf, nil
+	case "error":
+		return log.Errorf, nil
+	case "info":
+		return log.Infof, nil
+	case "debug":
+		return log.Debugf, nil
+	default:
+		return nil, c.Err("unknown log level argument in consolidate")
+	}
+}

plugin/errors/setup_test.go

 package errors
 
 import (
+	"bytes"
+	golog "log"
+	"strings"
 	"testing"
 
 	"github.com/coredns/caddy"
+	clog "github.com/coredns/coredns/plugin/pkg/log"
 )
 
 func TestErrorsParse(t *testing.T) {
@@ -67,3 +71,65 @@ func TestErrorsParse(t *testing.T) {
 		}
 	}
 }
+
+func TestProperLogCallbackIsSet(t *testing.T) {
+	tests := []struct {
+		name             string
+		inputErrorsRules string
+		wantLogLevel     string
+	}{
+		{
+			name: "warn is parsed properly",
+			inputErrorsRules: `errors {
+		        consolidate 1m .* warn
+		    }`,
+			wantLogLevel: "[WARNING]",
+		},
+		{
+			name: "error is parsed properly",
+			inputErrorsRules: `errors {
+		        consolidate 1m .* error
+		    }`,
+			wantLogLevel: "[ERROR]",
+		},
+		{
+			name: "info is parsed properly",
+			inputErrorsRules: `errors {
+		        consolidate 1m .* info
+		    }`,
+			wantLogLevel: "[INFO]",
+		},
+		{
+			name: "debug is parsed properly",
+			inputErrorsRules: `errors {
+		        consolidate 1m .* debug
+		    }`,
+			wantLogLevel: "[DEBUG]",
+		},
+		{
+			name: "default is error",
+			inputErrorsRules: `errors {
+		        consolidate 1m .*
+		    }`,
+			wantLogLevel: "[ERROR]",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			buf := bytes.Buffer{}
+			golog.SetOutput(&buf)
+			clog.D.Set()
+
+			c := caddy.NewTestController("dns", tt.inputErrorsRules)
+			h, _ := errorsParse(c)
+
+			l := h.patterns[0].logCallback
+			l("some error happened")
+
+			if log := buf.String(); !strings.Contains(log, tt.wantLogLevel) {
+				t.Errorf("Expected log %q, but got %q", tt.wantLogLevel, log)
+			}
+		})
+	}
+}