feat: add backend definition and new function

pkg/backend/backend.go

@@ -0,0 +1,90 @@
+package backend
+
+import (
+	"errors"
+	"fmt"
+
+	v1 "kusionstack.io/kusion/pkg/apis/core/v1"
+	"kusionstack.io/kusion/pkg/backend/storages"
+	"kusionstack.io/kusion/pkg/config"
+)
+
+// Backend is used to provide the storage service for Workspace, Spec and State.
+type Backend interface {
+	// todo: add functions to parse storage for workspace, spec and state, the format is like the following:
+	// WorkspaceStorage() workspace.Storage
+	// StateStorage(projectName, stackName string) state.Storage
+	// SpecStorage(projectName, stackName string) spec.Storage
+}
+
+// NewBackend creates the Backend with the configuration set in the Kusion configuration file. If the
+// backend configuration of the specified name does not exist or is invalid, NewBackend will get failed.
+// If the input name is empty, use the current backend. If no current backend is specified or backends
+// config is empty, use the default local storage.
+func NewBackend(name string) (Backend, error) {
+	var emptyCfg bool
+	cfg, err := config.GetConfig()
+	if errors.Is(err, config.ErrEmptyConfig) {
+		emptyCfg = true
+	} else if err != nil {
+		return nil, err
+	}
+	if cfg.Backends == nil {
+		emptyCfg = true
+	}
+
+	var bkCfg *v1.BackendConfig
+	if name == "" {
+		if emptyCfg || cfg.Backends.Current == "" {
+			// if empty backends config or empty current backend, use the default storage
+			return storages.NewDefaultStorage(), nil
+		}
+		name = cfg.Backends.Current
+		bkCfg = cfg.Backends.Backends[name]
+	} else {
+		bkCfg = cfg.Backends.Backends[name]
+		if bkCfg == nil {
+			return nil, fmt.Errorf("config of backend %s does not exist", name)
+		}
+	}
+
+	var storage Backend
+	switch bkCfg.Type {
+	case v1.BackendTypeLocal:
+		bkConfig := bkCfg.ToLocalBackend()
+		return storages.NewLocalStorage(bkConfig), nil
+	case v1.BackendTypeMysql:
+		bkConfig := bkCfg.ToMysqlBackend()
+		storages.CompleteMysqlConfig(bkConfig)
+		if err = storages.ValidateMysqlConfig(bkConfig); err != nil {
+			return nil, fmt.Errorf("invalid config of backend %s: %w", name, err)
+		}
+		storage, err = storages.NewMysqlStorage(bkConfig)
+		if err != nil {
+			return nil, fmt.Errorf("new mysql storage of backend %s failed, %w", name, err)
+		}
+	case v1.BackendTypeOss:
+		bkConfig := bkCfg.ToOssBackend()
+		storages.CompleteOssConfig(bkConfig)
+		if err = storages.ValidateOssConfig(bkConfig); err != nil {
+			return nil, fmt.Errorf("invalid config of backend %s: %w", name, err)
+		}
+		storage, err = storages.NewOssStorage(bkConfig)
+		if err != nil {
+			return nil, fmt.Errorf("new oss storage of backend %s failed, %w", name, err)
+		}
+	case v1.BackendTypeS3:
+		bkConfig := bkCfg.ToS3Backend()
+		storages.CompleteS3Config(bkConfig)
+		if err = storages.ValidateS3Config(bkConfig); err != nil {
+			return nil, fmt.Errorf("invalid config of backend %s: %w", name, err)
+		}
+		storage, err = storages.NewS3Storage(bkConfig)
+		if err != nil {
+			return nil, fmt.Errorf("new s3 storage of backend %s failed, %w", name, err)
+		}
+	default:
+		return nil, fmt.Errorf("invalid type %s of backend %s", bkCfg.Type, name)
+	}
+	return storage, nil
+}

pkg/backend/backend_test.go

@@ -0,0 +1,158 @@
+package backend
+
+import (
+	"os"
+	"reflect"
+	"testing"
+
+	"github.com/bytedance/mockey"
+	"github.com/stretchr/testify/assert"
+
+	v1 "kusionstack.io/kusion/pkg/apis/core/v1"
+	"kusionstack.io/kusion/pkg/backend/storages"
+	"kusionstack.io/kusion/pkg/config"
+)
+
+func mockConfig() *v1.Config {
+	return &v1.Config{
+		Backends: &v1.BackendConfigs{
+			Current: "pre",
+			Backends: map[string]*v1.BackendConfig{
+				"dev": {
+					Type: v1.BackendTypeLocal,
+					Configs: map[string]any{
+						v1.BackendLocalPath: "/etc",
+					},
+				},
+				"pre": {
+					Type: v1.BackendTypeMysql,
+					Configs: map[string]any{
+						v1.BackendMysqlDBName: "kusion",
+						v1.BackendMysqlUser:   "kk",
+						v1.BackendMysqlHost:   "127.0.0.1",
+						v1.BackendMysqlPort:   3306,
+					},
+				},
+				"staging": {
+					Type: v1.BackendTypeOss,
+					Configs: map[string]any{
+						v1.BackendGenericOssEndpoint: "http://oss-cn-hangzhou.aliyuncs.com",
+						v1.BackendGenericOssBucket:   "kusion",
+					},
+				},
+				"prod": {
+					Type: v1.BackendTypeS3,
+					Configs: map[string]any{
+						v1.BackendGenericOssBucket: "kusion",
+					},
+				},
+			},
+		},
+	}
+}
+
+func mockNewStorage() {
+	mockey.Mock(storages.NewLocalStorage).Return(&storages.LocalStorage{}).Build()
+	mockey.Mock(storages.NewMysqlStorage).Return(&storages.MysqlStorage{}, nil).Build()
+	mockey.Mock(storages.NewOssStorage).Return(&storages.OssStorage{}, nil).Build()
+	mockey.Mock(storages.NewS3Storage).Return(&storages.S3Storage{}, nil).Build()
+}
+
+func TestNewBackend(t *testing.T) {
+	testcases := []struct {
+		name    string
+		success bool
+		cfg     *v1.Config
+		envs    map[string]string
+		bkName  string
+		storage Backend
+	}{
+		{
+			name:    "new default backend",
+			success: true,
+			cfg: func() *v1.Config {
+				cfg := mockConfig()
+				cfg.Backends.Current = ""
+				return cfg
+			}(),
+			envs:    nil,
+			bkName:  "",
+			storage: &storages.LocalStorage{},
+		},
+		{
+			name:    "new current backend",
+			success: true,
+			cfg:     mockConfig(),
+			envs:    nil,
+			bkName:  "",
+			storage: &storages.MysqlStorage{},
+		},
+		{
+			name:    "new local backend",
+			success: true,
+			cfg:     mockConfig(),
+			envs:    nil,
+			bkName:  "dev",
+			storage: &storages.LocalStorage{},
+		},
+		{
+			name:    "new local backend",
+			success: true,
+			cfg:     mockConfig(),
+			envs:    nil,
+			bkName:  "dev",
+			storage: &storages.LocalStorage{},
+		},
+		{
+			name:    "new mysql backend",
+			success: true,
+			cfg:     mockConfig(),
+			envs: map[string]string{
+				v1.EnvBackendMysqlPassword: "fake-password",
+			},
+			bkName:  "pre",
+			storage: &storages.MysqlStorage{},
+		},
+		{
+			name:    "new oss backend",
+			success: true,
+			cfg:     mockConfig(),
+			envs: map[string]string{
+				v1.EnvOssAccessKeyID:     "fake-ak",
+				v1.EnvOssAccessKeySecret: "fake-sk",
+			},
+			bkName:  "staging",
+			storage: &storages.OssStorage{},
+		},
+		{
+			name:    "new s3 backend",
+			success: true,
+			cfg:     mockConfig(),
+			envs: map[string]string{
+				v1.EnvAwsRegion:          "us-east-1",
+				v1.EnvAwsAccessKeyID:     "fake-ak",
+				v1.EnvAwsSecretAccessKey: "fake-sk",
+			},
+			bkName:  "prod",
+			storage: &storages.S3Storage{},
+		},
+	}
+
+	for _, tc := range testcases {
+		t.Run(tc.name, func(t *testing.T) {
+			mockey.PatchConvey("mock config", t, func() {
+				mockey.Mock(config.GetConfig).Return(tc.cfg, nil).Build()
+				mockNewStorage()
+				for k, v := range tc.envs {
+					_ = os.Setenv(k, v)
+				}
+				storage, err := NewBackend(tc.bkName)
+				assert.Equal(t, tc.success, err == nil)
+				assert.Equal(t, reflect.TypeOf(tc.storage), reflect.TypeOf(storage))
+				for k := range tc.envs {
+					_ = os.Unsetenv(k)
+				}
+			})
+		})
+	}
+}

pkg/backend/storages/completion_test.go

@@ -84,6 +84,9 @@ func TestCompleteOssConfig(t *testing.T) {
 			}
 			CompleteOssConfig(tc.config)
 			assert.Equal(t, tc.completeConfig, tc.config)
+			for k := range tc.envs {
+				_ = os.Unsetenv(k)
+			}
 		})
 	}
 }
@@ -127,6 +130,9 @@ func TestCompleteS3Config(t *testing.T) {
 			}
 			CompleteS3Config(tc.config)
 			assert.Equal(t, tc.completeConfig, tc.config)
+			for k := range tc.envs {
+				_ = os.Unsetenv(k)
+			}
 		})
 	}
 }

pkg/backend/storages/local.go

@@ -14,3 +14,7 @@ type LocalStorage struct {
 func NewLocalStorage(config *v1.BackendLocalConfig) *LocalStorage {
 	return &LocalStorage{path: config.Path}
 }
+
+func NewDefaultStorage() *LocalStorage {
+	return NewLocalStorage(&v1.BackendLocalConfig{})
+}