Apply python path resolution to plugins (#1990)

* Symlink python3 to python
* Apply path resolution to plugins

pkg/plugin/raw.go

@@ -29,6 +29,19 @@ type rawPluginTask struct {
 	done      chan bool
 }
 
+func FindPythonExecutable() (string, error) {
+	_, err := exec.LookPath("python3")
+
+	if err != nil {
+		_, err = exec.LookPath("python")
+		if err != nil {
+			return "", err
+		}
+		return "python", nil
+	}
+	return "python3", nil
+}
+
 func (t *rawPluginTask) Start() error {
 	if t.started {
 		return errors.New("task already started")
@@ -39,6 +52,13 @@ func (t *rawPluginTask) Start() error {
 		return fmt.Errorf("empty exec value in operation %s", t.operation.Name)
 	}
 
+	if command[0] == "python" || command[0] == "python3" {
+		executable, err := FindPythonExecutable()
+		if err == nil {
+			command[0] = executable
+		}
+	}
+
 	cmd := exec.Command(command[0], command[1:]...)
 
 	stdin, err := cmd.StdinPipe()