Implement checking in predicates

plugin/pkg/scheduler/algorithm/predicates/predicates_test.go

@@ -18,11 +18,13 @@ package predicates
 
 import (
 	"fmt"
+	"os/exec"
 	"reflect"
 	"testing"
 
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/resource"
+	"k8s.io/kubernetes/pkg/util/codeinspector"
 	"k8s.io/kubernetes/plugin/pkg/scheduler/algorithm"
 	"k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache"
 )
@@ -1408,3 +1410,48 @@ func TestEBSVolumeCountConflicts(t *testing.T) {
 		}
 	}
 }
+
+func TestPredicatesRegistered(t *testing.T) {
+	var functionNames []string
+
+	// Files and directories which predicates may be referenced
+	targetFiles := []string{
+		"./../../algorithmprovider/defaults/defaults.go", // Default algorithm
+		"./../../factory/plugins.go",                     // Registered in init()
+		"./../../../../../pkg/",                          // kubernetes/pkg, often used by kubelet or controller
+	}
+
+	// List all golang source files under ./predicates/, excluding test files and sub-directories.
+	files, err := codeinspector.GetSourceCodeFiles(".")
+
+	if err != nil {
+		t.Errorf("unexpected error: %v when listing files in current directory", err)
+	}
+
+	// Get all public predicates in files.
+	for _, filePath := range files {
+		functions, err := codeinspector.GetPublicFunctions(filePath)
+		if err == nil {
+			functionNames = append(functionNames, functions...)
+		} else {
+			t.Errorf("unexpected error when parsing %s", filePath)
+		}
+	}
+
+	// Check if all public predicates are referenced in target files.
+	for _, functionName := range functionNames {
+		args := []string{"-rl", functionName}
+		args = append(args, targetFiles...)
+
+		err := exec.Command("grep", args...).Run()
+		if err != nil {
+			switch err.Error() {
+			case "exit status 2":
+				t.Errorf("unexpected error when checking %s", functionName)
+			case "exit status 1":
+				t.Errorf("predicate %s is implemented as public but seems not registered or used in any other place",
+					functionName)
+			}
+		}
+	}
+}