refactor: define api register of supernode to add api

Signed-off-by: lowzj <[email protected]>

supernode/server/api/api.go

@@ -0,0 +1,63 @@
+/*
+ * Copyright The Dragonfly 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 api
+
+var handlerCategories map[string][]*HandlerSpec
+
+const (
+	// VersionedPrefix is recommended, any new API should start with this prefix.
+	VersionedPrefix = "/api/v1"
+
+	// LegacyPrefix is deprecated, just for compatibility with the old version.
+	LegacyPrefix = ""
+)
+
+var (
+	VersionedCategory = &Category{Name: "versioned api", Prefix: VersionedPrefix}
+	LegacyCategory    = &Category{Name: "legacy api", Prefix: LegacyPrefix}
+)
+
+// Category groups the APIs.
+type Category struct {
+	Name   string
+	Prefix string
+}
+
+// Register add an API into supernode server with current api version.
+func Register(handlers ...*HandlerSpec) {
+	for _, h := range handlers {
+		registerAPI(VersionedCategory, h)
+	}
+}
+
+// RegisterLegacy is deprecated, just for compatibility with the old version,
+// please do not use it to add new API.
+func RegisterLegacy(h *HandlerSpec) {
+	registerAPI(LegacyCategory, h)
+}
+
+func registerAPI(c *Category, h *HandlerSpec) {
+	if c == nil || validate(h) {
+		return
+	}
+	handlers := handlerCategories[c.Name]
+	handlerCategories[c.Name] = append(handlers, h)
+}
+
+func validate(h *HandlerSpec) bool {
+	return h != nil && h.HandlerFunc != nil && h.Method != ""
+}

supernode/server/api/handler.go

@@ -0,0 +1,32 @@
+/*
+ * Copyright The Dragonfly 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 api
+
+import (
+	"context"
+	"net/http"
+)
+
+// HandlerSpec describes a HTTP api
+type HandlerSpec struct {
+	Method      string
+	Path        string
+	HandlerFunc HandlerFunc
+}
+
+// HandlerFunc is the http request handler.
+type HandlerFunc func(ctx context.Context, rw http.ResponseWriter, req *http.Request) error

supernode/server/api/utils.go

@@ -0,0 +1,74 @@
+/*
+ * Copyright The Dragonfly 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 api
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+
+	"github.com/dragonflyoss/Dragonfly/apis/types"
+	"github.com/dragonflyoss/Dragonfly/pkg/errortypes"
+
+	"github.com/go-openapi/strfmt"
+)
+
+// ValidateFunc validates the request parameters.
+type ValidateFunc func(registry strfmt.Registry) error
+
+// ParseJSONRequest parses the request parameter formed by JSON to a object.
+func ParseJSONRequest(body io.Reader, request interface{}, validator ValidateFunc) error {
+	if err := json.NewDecoder(body).Decode(request); err != nil {
+		if err == io.EOF {
+			return errortypes.New(http.StatusBadRequest, "empty body")
+		}
+		return errortypes.New(http.StatusBadRequest, err.Error())
+	}
+	if validator != nil {
+		if err := validator(strfmt.NewFormats()); err != nil {
+			return errortypes.New(http.StatusBadRequest, err.Error())
+		}
+	}
+	return nil
+}
+
+// EncodeResponse encodes response in json.
+func EncodeResponse(rw http.ResponseWriter, statusCode int, data interface{}) error {
+	rw.Header().Set("Content-Type", "application/json")
+	rw.WriteHeader(statusCode)
+	return json.NewEncoder(rw).Encode(data)
+}
+
+// HandleErrorResponse handles err from daemon side and constructs response for client side.
+func HandleErrorResponse(w http.ResponseWriter, err error) {
+	var (
+		code   int
+		errMsg string
+	)
+
+	// By default, daemon side returns code 500 if error happens.
+	code = http.StatusInternalServerError
+	if e, ok := err.(*errortypes.DfError); ok {
+		code = e.Code
+		errMsg = e.Msg
+	}
+
+	_ = EncodeResponse(w, code, types.ErrorResponse{
+		Code:    int64(code),
+		Message: errMsg,
+	})
+}

supernode/server/router.go

@@ -24,6 +24,7 @@ import (
 
 	"github.com/dragonflyoss/Dragonfly/apis/types"
 	"github.com/dragonflyoss/Dragonfly/version"
+
 	"github.com/gorilla/mux"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"