[v3.2] Add grafana dashboard importing API (#11)

* Add API to import grafana templates to kubesphere dashboard
* Merge and fix the latest codes from kubesphere #2501

Signed-off-by: zhu733756 <talonzhu@yunify.com>

vendor/github.com/grafana-tools/sdk/rest-request.go

@@ -0,0 +1,118 @@
+package sdk
+
+/*
+   Copyright 2016 Alexander I.Grafov <grafov@gmail.com>
+   Copyright 2016-2019 The Grafana SDK 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.
+
+   ॐ तारे तुत्तारे तुरे स्व
+*/
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"path"
+	"strings"
+)
+
+// DefaultHTTPClient initialized Grafana with appropriate conditions.
+// It allows you globally redefine HTTP client.
+var DefaultHTTPClient = http.DefaultClient
+
+// Client uses Grafana REST API for interacting with Grafana server.
+type Client struct {
+	baseURL   string
+	key       string
+	basicAuth bool
+	client    *http.Client
+}
+
+// StatusMessage reflects status message as it returned by Grafana REST API.
+type StatusMessage struct {
+	ID      *uint   `json:"id"`
+	OrgID   *uint   `json:"orgId"`
+	Message *string `json:"message"`
+	Slug    *string `json:"slug"`
+	Version *int    `json:"version"`
+	Status  *string `json:"status"`
+	UID     *string `json:"uid"`
+	URL     *string `json:"url"`
+}
+
+// NewClient initializes client for interacting with an instance of Grafana server;
+// apiKeyOrBasicAuth accepts either 'username:password' basic authentication credentials,
+// or a Grafana API key
+func NewClient(apiURL, apiKeyOrBasicAuth string, client *http.Client) *Client {
+	key := ""
+	basicAuth := strings.Contains(apiKeyOrBasicAuth, ":")
+	baseURL, _ := url.Parse(apiURL)
+	if !basicAuth {
+		key = fmt.Sprintf("Bearer %s", apiKeyOrBasicAuth)
+	} else {
+		parts := strings.Split(apiKeyOrBasicAuth, ":")
+		baseURL.User = url.UserPassword(parts[0], parts[1])
+	}
+	return &Client{baseURL: baseURL.String(), basicAuth: basicAuth, key: key, client: client}
+}
+
+func (r *Client) get(ctx context.Context, query string, params url.Values) ([]byte, int, error) {
+	return r.doRequest(ctx, "GET", query, params, nil)
+}
+
+func (r *Client) patch(ctx context.Context, query string, params url.Values, body []byte) ([]byte, int, error) {
+	return r.doRequest(ctx, "PATCH", query, params, bytes.NewBuffer(body))
+}
+
+func (r *Client) put(ctx context.Context, query string, params url.Values, body []byte) ([]byte, int, error) {
+	return r.doRequest(ctx, "PUT", query, params, bytes.NewBuffer(body))
+}
+
+func (r *Client) post(ctx context.Context, query string, params url.Values, body []byte) ([]byte, int, error) {
+	return r.doRequest(ctx, "POST", query, params, bytes.NewBuffer(body))
+}
+
+func (r *Client) delete(ctx context.Context, query string) ([]byte, int, error) {
+	return r.doRequest(ctx, "DELETE", query, nil, nil)
+}
+
+func (r *Client) doRequest(ctx context.Context, method, query string, params url.Values, buf io.Reader) ([]byte, int, error) {
+	u, _ := url.Parse(r.baseURL)
+	u.Path = path.Join(u.Path, query)
+	if params != nil {
+		u.RawQuery = params.Encode()
+	}
+	req, err := http.NewRequest(method, u.String(), buf)
+	if err != nil {
+		return nil, 0, err
+	}
+	req = req.WithContext(ctx)
+	if !r.basicAuth {
+		req.Header.Set("Authorization", r.key)
+	}
+	req.Header.Set("Accept", "application/json")
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("User-Agent", "autograf")
+	resp, err := r.client.Do(req)
+	if err != nil {
+		return nil, 0, err
+	}
+	data, err := ioutil.ReadAll(resp.Body)
+	resp.Body.Close()
+	return data, resp.StatusCode, err
+}