Fix context test

Author: baptistedonaux

context.go

@@ -157,10 +157,11 @@ type Docker struct {
 func GetCurrentContainerID() string {
 	file, err := os.Open("/proc/self/cgroup")
 
-	if os.IsNotExist(err) {
-		return ""
-	} else if err != nil {
-		log.Printf("Fail to open /proc/self/cgroup: %s\n", err)
+	if err != nil {
+		if os.IsExist(err) {
+			log.Printf("Fail to open /proc/self/cgroup: %s\n", err)
+		}
+
 		return ""
 	}
 

context_test.go

@@ -7,7 +7,7 @@ import (
 func TestGetCurrentContainerID(t *testing.T) {
 	currentContainerID := GetCurrentContainerID()
 
-	if len(currentContainerID) != 64 {
+	if len(currentContainerID) != 0 && len(currentContainerID) != 64 {
 		t.Fail()
 	}
 }