refactor: define api register of supernode to add api

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

supernode/server/api/api.go

@@ -0,0 +1,87 @@
+/*
+ * 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 (
+	// V1 is recommended, any new API should be registered in this category.
+	V1 = newCategory("v1 api", "/api/v1")
+
+	// Extension allows users to register extension APIs into supernode.
+	// Customized APIs should be registered by using this category.
+	// It can distinguish between Dragonfly's core APIs and customized APIs.
+	// And supernode provides `/api/ext` to list all the registered APIs in this
+	// category.
+	Extension = newCategory("extension api", "/api/ext")
+
+	// Legacy is deprecated, just for compatibility with the old version,
+	// please do not use it to add new API.
+	Legacy = newCategory("legacy api", "")
+)
+
+var (
+	apiCategories = make(map[string]*category)
+)
+
+func newCategory(name, prefix string) *category {
+	if c, ok := apiCategories[name]; ok && c != nil {
+		return c
+	}
+
+	apiCategories[name] = &category{
+		name:         name,
+		prefix:       prefix,
+		handlerSpecs: make([]*HandlerSpec, 0),
+	}
+	return apiCategories[name]
+}
+
+// category groups the APIs.
+type category struct {
+	name         string
+	prefix       string
+	handlerSpecs []*HandlerSpec
+}
+
+// Register registers an API into this API category.
+func (c *category) Register(h *HandlerSpec) *category {
+	if !validate(h) {
+		return c
+	}
+	c.handlerSpecs = append(c.handlerSpecs, h)
+	return c
+}
+
+// Name returns the name of this category.
+func (c *category) Name() string {
+	return c.name
+}
+
+// Prefix returns the api prefix of this category.
+func (c *category) Prefix() string {
+	return c.prefix
+}
+
+// Handlers returns all of the APIs registered into this category.
+func (c *category) Handlers() []*HandlerSpec {
+	return c.handlerSpecs
+}
+
+// -----------------------------------------------------------------------------
+
+func validate(h *HandlerSpec) bool {
+	return h != nil && h.HandlerFunc != nil && h.Method != ""
+}

supernode/server/api/api_test.go

@@ -0,0 +1,75 @@
+/*
+ * 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"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+)
+
+func TestSuite(t *testing.T) {
+	suite.Run(t, new(APISuite))
+}
+
+type APISuite struct {
+	suite.Suite
+	validHandler   *HandlerSpec
+	invalidHandler *HandlerSpec
+}
+
+func (s *APISuite) SetupSuite() {
+	s.validHandler = &HandlerSpec{
+		Method: "GET",
+		HandlerFunc: func(ctx context.Context, rw http.ResponseWriter, req *http.Request) error {
+			return nil
+		},
+	}
+	s.invalidHandler = &HandlerSpec{}
+}
+
+func (s *APISuite) SetupTest() {
+	for _, c := range []*category{V1, Extension, Legacy} {
+		c.HandlerSpecs = nil
+	}
+}
+
+func (s *APISuite) TestCategory_Register() {
+	var cases = []struct {
+		c *category
+		h *HandlerSpec
+	}{
+		{V1, s.invalidHandler},
+		{V1, s.validHandler},
+		{Extension, s.validHandler},
+		{Legacy, s.validHandler},
+	}
+
+	for _, v := range cases {
+		before := v.c.HandlerSpecs
+		v.c.Register(v.h)
+		after := v.c.HandlerSpecs
+		if s.invalidHandler == v.h {
+			s.Equal(before, after)
+		} else if s.validHandler == v.h {
+			s.Equal(len(before)+1, len(after))
+			s.Equal(after[len(after)-1], v.h)
+		}
+	}
+}

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 an 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"