From c0e0da7ef6364ee682174e8cd3b218d6ff75ab69 Mon Sep 17 00:00:00 2001
From: Daniel Nelson <daniel@wavesofdawn.com>
Date: Mon, 4 Mar 2019 12:35:57 -0800
Subject: [PATCH] Fix conversion from string float to integer (#5518)

---
 plugins/processors/converter/converter.go     | 28 +++++++++++----
 .../processors/converter/converter_test.go    | 34 ++++++++++++-------
 2 files changed, 43 insertions(+), 19 deletions(-)

diff --git a/plugins/processors/converter/converter.go b/plugins/processors/converter/converter.go
index 50fd195e01e77..3c9b74f3fe165 100644
--- a/plugins/processors/converter/converter.go
+++ b/plugins/processors/converter/converter.go
@@ -336,7 +336,7 @@ func toInteger(v interface{}) (int64, bool) {
 		} else if value > float64(math.MaxInt64) {
 			return math.MaxInt64, true
 		} else {
-			return int64(value), true
+			return int64(Round(value)), true
 		}
 	case bool:
 		if value {
@@ -345,8 +345,11 @@ func toInteger(v interface{}) (int64, bool) {
 			return 0, true
 		}
 	case string:
-		result, err := strconv.ParseInt(value, 10, 64)
-		return result, err == nil
+		result, err := strconv.ParseFloat(value, 64)
+		if err != nil {
+			return 0, false
+		}
+		return toInteger(result)
 	}
 	return 0, false
 }
@@ -367,7 +370,7 @@ func toUnsigned(v interface{}) (uint64, bool) {
 		} else if value > float64(math.MaxUint64) {
 			return math.MaxUint64, true
 		} else {
-			return uint64(value), true
+			return uint64(Round(value)), true
 		}
 	case bool:
 		if value {
@@ -376,8 +379,11 @@ func toUnsigned(v interface{}) (uint64, bool) {
 			return 0, true
 		}
 	case string:
-		result, err := strconv.ParseUint(value, 10, 64)
-		return result, err == nil
+		result, err := strconv.ParseFloat(value, 64)
+		if err != nil {
+			return 0, false
+		}
+		return toUnsigned(result)
 	}
 	return 0, false
 }
@@ -419,6 +425,16 @@ func toString(v interface{}) (string, bool) {
 	return "", false
 }
 
+// math.Round was not added until Go 1.10, can be removed when support for Go
+// 1.9 is dropped.
+func Round(x float64) float64 {
+	t := math.Trunc(x)
+	if math.Abs(x-t) >= 0.5 {
+		return t + math.Copysign(1, x)
+	}
+	return t
+}
+
 func logPrintf(format string, v ...interface{}) {
 	log.Printf("D! [processors.converter] "+format, v...)
 }
diff --git a/plugins/processors/converter/converter_test.go b/plugins/processors/converter/converter_test.go
index 76839760d9ced..1b00cedf93935 100644
--- a/plugins/processors/converter/converter_test.go
+++ b/plugins/processors/converter/converter_test.go
@@ -129,8 +129,8 @@ func TestConverter(t *testing.T) {
 			converter: &Converter{
 				Fields: &Conversion{
 					String:   []string{"a"},
-					Integer:  []string{"b"},
-					Unsigned: []string{"c"},
+					Integer:  []string{"b", "b1", "b2"},
+					Unsigned: []string{"c", "c1", "c2"},
 					Boolean:  []string{"d"},
 					Float:    []string{"e"},
 					Tag:      []string{"f"},
@@ -141,12 +141,16 @@ func TestConverter(t *testing.T) {
 					"cpu",
 					map[string]string{},
 					map[string]interface{}{
-						"a": "howdy",
-						"b": "42",
-						"c": "42",
-						"d": "true",
-						"e": "42.0",
-						"f": "foo",
+						"a":  "howdy",
+						"b":  "42",
+						"b1": "42.2",
+						"b2": "42.5",
+						"c":  "42",
+						"c1": "42.2",
+						"c2": "42.5",
+						"d":  "true",
+						"e":  "42.0",
+						"f":  "foo",
 					},
 					time.Unix(0, 0),
 				),
@@ -158,11 +162,15 @@ func TestConverter(t *testing.T) {
 						"f": "foo",
 					},
 					map[string]interface{}{
-						"a": "howdy",
-						"b": int64(42),
-						"c": uint64(42),
-						"d": true,
-						"e": 42.0,
+						"a":  "howdy",
+						"b":  int64(42),
+						"b1": int64(42),
+						"b2": int64(43),
+						"c":  uint64(42),
+						"c1": uint64(42),
+						"c2": uint64(43),
+						"d":  true,
+						"e":  42.0,
 					},
 					time.Unix(0, 0),
 				),