Fix ints being capped at 32-bits on 32-bit archs (#4054)

(cherry picked from commit fe4d3cd117)

plugins/parsers/influx/parser_test.go

@@ -282,7 +282,7 @@ var ptests = []struct {
 					"cpu",
 					map[string]string{},
 					map[string]interface{}{
-						"value": 9223372036854775807,
+						"value": int64(9223372036854775807),
 					},
 					time.Unix(42, 0),
 				),

plugins/serializers/influx/influx.go

@@ -12,7 +12,7 @@ import (
 	"github.com/influxdata/telegraf"
 )
 
-const MaxInt = int(^uint(0) >> 1)
+const MaxInt64 = int64(^uint64(0) >> 1)
 
 type FieldSortOrder int
 
@@ -270,10 +270,10 @@ func (s *Serializer) appendFieldValue(buf []byte, value interface{}) ([]byte, er
 		if s.fieldTypeSupport&UintSupport != 0 {
 			return appendUintField(buf, v), nil
 		} else {
-			if v <= uint64(MaxInt) {
+			if v <= uint64(MaxInt64) {
 				return appendIntField(buf, int64(v)), nil
 			} else {
-				return appendIntField(buf, int64(MaxInt)), nil
+				return appendIntField(buf, int64(MaxInt64)), nil
 			}
 		}
 	case int64:

plugins/serializers/influx/influx_test.go

@@ -129,6 +129,20 @@ var tests = []struct {
 		),
 		output: []byte("cpu value=42i 0\n"),
 	},
+	{
+		name: "integer field 64-bit",
+		input: MustMetric(
+			metric.New(
+				"cpu",
+				map[string]string{},
+				map[string]interface{}{
+					"value": int64(123456789012345),
+				},
+				time.Unix(0, 0),
+			),
+		),
+		output: []byte("cpu value=123456789012345i 0\n"),
+	},
 	{
 		name: "uint field",
 		input: MustMetric(