Merge pull request #124 from ddosify/fix/prevent-race-on-dynamic-env

prevent race on calls to faker func

Jenkinsfile

@@ -37,6 +37,7 @@ fi'''
       steps {
         lock('multi_branch_server') {
           sh 'go run --race main.go -t https://servdown.com/ -d 1 -n 1500'
+          sh 'go test -race -run ^TestDynamicVariableRace$ go.ddosify.com/ddosify/core/scenario/scripting/injection'
         }
       }
     }

core/scenario/scripting/injection/dynamic_test.go

@@ -0,0 +1,15 @@
+package injection
+
+import (
+	"testing"
+)
+
+func TestDynamicVariableRace(t *testing.T) {
+	num := 10
+	ei := EnvironmentInjector{}
+	for key := range dynamicFakeDataMap {
+		for i := 0; i < num; i++ {
+			go ei.getFakeData(key)
+		}
+	}
+}

core/scenario/scripting/injection/environment.go

@@ -7,6 +7,7 @@ import (
 	"reflect"
 	"regexp"
 	"strings"
+	"sync"
 	"time"
 
 	"go.ddosify.com/ddosify/core/types/regex"
@@ -17,6 +18,7 @@ type EnvironmentInjector struct {
 	jr  *regexp.Regexp
 	dr  *regexp.Regexp
 	jdr *regexp.Regexp
+	mu  sync.Mutex
 }
 
 func (ei *EnvironmentInjector) Init() {
@@ -34,8 +36,13 @@ func (ei *EnvironmentInjector) getFakeData(key string) (interface{}, error) {
 		return nil, fmt.Errorf("%s is not a valid dynamic variable", key)
 	}
 
-	res := reflect.ValueOf(fakeFunc).Call(nil)[0].Interface()
-	return res, nil
+	preventRaceOnRandomFunc := func(fakeFunc interface{}) interface{} {
+		ei.mu.Lock()
+		defer ei.mu.Unlock()
+		return reflect.ValueOf(fakeFunc).Call(nil)[0].Interface()
+	}
+
+	return preventRaceOnRandomFunc(fakeFunc), nil
 }
 
 func truncateTag(tag string, rx string) string {