Merge pull request #119057 from vadasambar/feat/scheduler/expose-load-config-func

refactor: export `loadConfigFile` as a public function `LoadConfigFile`

cmd/kube-scheduler/app/options/configfile.go

@@ -30,7 +30,8 @@ import (
 	configv1beta3 "k8s.io/kubernetes/pkg/scheduler/apis/config/v1beta3"
 )
 
-func loadConfigFromFile(logger klog.Logger, file string) (*config.KubeSchedulerConfiguration, error) {
+// LoadConfigFromFile loads scheduler config from the specified file path
+func LoadConfigFromFile(logger klog.Logger, file string) (*config.KubeSchedulerConfiguration, error) {
 	data, err := os.ReadFile(file)
 	if err != nil {
 		return nil, err

cmd/kube-scheduler/app/options/configfile_test.go

@@ -0,0 +1,136 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package options
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"k8s.io/klog/v2"
+	"k8s.io/kubernetes/pkg/scheduler/apis/config"
+)
+
+const (
+	apiVersionMissing = "'apiVersion' is missing"
+	apiVersionTooOld  = "no kind \"KubeSchedulerConfiguration\" is registered for" +
+		" version \"kubescheduler.config.k8s.io/v1alpha1\""
+	fileNotFound = "no such file or directory"
+
+	// schedulerConfigMinimalCorrect is the minimal
+	// correct scheduler config
+	schedulerConfigMinimalCorrect = `
+apiVersion: kubescheduler.config.k8s.io/v1
+kind: KubeSchedulerConfiguration`
+
+	// schedulerConfigDecodeErr is the scheduler config
+	// which throws decoding error when we try to load it
+	schedulerConfigDecodeErr = `
+kind: KubeSchedulerConfiguration`
+
+	// schedulerConfigVersionTooOld is the scheduler config
+	// which throws error because the config version 'v1alpha1'
+	// is too old
+	schedulerConfigVersionTooOld = `
+apiVersion: kubescheduler.config.k8s.io/v1alpha1
+kind: KubeSchedulerConfiguration
+`
+)
+
+func TestLoadConfigFromFile(t *testing.T) {
+	tmpDir, err := os.MkdirTemp("", "scheduler-configs")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	correctConfigFile := filepath.Join(tmpDir, "correct_config.yaml")
+	if err := os.WriteFile(correctConfigFile,
+		[]byte(schedulerConfigMinimalCorrect),
+		os.FileMode(0600)); err != nil {
+		t.Fatal(err)
+	}
+
+	decodeErrConfigFile := filepath.Join(tmpDir, "decode_err_no_version_config.yaml")
+	if err := os.WriteFile(decodeErrConfigFile,
+		[]byte(schedulerConfigDecodeErr),
+		os.FileMode(0600)); err != nil {
+		t.Fatal(err)
+	}
+
+	versionTooOldConfigFile := filepath.Join(tmpDir, "version_too_old_config.yaml")
+	if err := os.WriteFile(versionTooOldConfigFile,
+		[]byte(schedulerConfigVersionTooOld),
+		os.FileMode(0600)); err != nil {
+		t.Fatal(err)
+	}
+
+	tests := []struct {
+		name           string
+		path           string
+		expectedErr    error
+		expectedConfig *config.KubeSchedulerConfiguration
+	}{
+		{
+			name:           "Empty scheduler config file path",
+			path:           "",
+			expectedErr:    fmt.Errorf(fileNotFound),
+			expectedConfig: nil,
+		},
+		{
+			name:           "Correct scheduler config",
+			path:           correctConfigFile,
+			expectedErr:    nil,
+			expectedConfig: &config.KubeSchedulerConfiguration{},
+		},
+		{
+			name:           "Scheduler config with decode error",
+			path:           decodeErrConfigFile,
+			expectedErr:    fmt.Errorf(apiVersionMissing),
+			expectedConfig: nil,
+		},
+		{
+			name:           "Scheduler config version too old",
+			path:           versionTooOldConfigFile,
+			expectedErr:    fmt.Errorf(apiVersionTooOld),
+			expectedConfig: nil,
+		},
+	}
+
+	logger := klog.FromContext(context.Background())
+
+	for i, test := range tests {
+		t.Run(fmt.Sprintf("case_%d: %s", i, test.name), func(t *testing.T) {
+			cfg, err := LoadConfigFromFile(logger, test.path)
+			if test.expectedConfig == nil {
+				assert.Nil(t, cfg)
+			} else {
+				assert.NotNil(t, cfg)
+			}
+
+			if test.expectedErr == nil {
+				assert.NoError(t, err)
+			} else {
+				assert.ErrorContains(t, err, test.expectedErr.Error())
+			}
+		})
+
+	}
+}

cmd/kube-scheduler/app/options/options.go

@@ -204,7 +204,7 @@ func (o *Options) ApplyTo(logger klog.Logger, c *schedulerappconfig.Config) erro
 		o.ApplyLeaderElectionTo(o.ComponentConfig)
 		c.ComponentConfig = *o.ComponentConfig
 	} else {
-		cfg, err := loadConfigFromFile(logger, o.ConfigFile)
+		cfg, err := LoadConfigFromFile(logger, o.ConfigFile)
 		if err != nil {
 			return err
 		}