add kiali client with authentication supports

Signed-off-by: Roland.Ma <rolandma@yunify.com>

pkg/simple/client/kiali/client.go

@@ -0,0 +1,174 @@
+/*
+Copyright 2021 KubeSphere 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 kiali
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"time"
+
+	"kubesphere.io/kubesphere/pkg/simple/client/cache"
+)
+
+// Kiali token Response
+type TokenResponse struct {
+	// The username for the token
+	Username string `json:"username"`
+	// The authentication token
+	Token string `json:"token"`
+	// The expired time for the token
+	ExpiresOn string `json:"expiresOn"`
+}
+
+// Kiali Authentication  Strategy
+type Strategy string
+
+const (
+	AuthStrategyToken     Strategy = "token"
+	AuthStrategyAnonymous Strategy = "anonymous"
+)
+
+const (
+	AuthURL            = "%s/kiali/api/authenticate"
+	KialiTokenCacheKey = "kubesphere:kubesphere:kiali"
+)
+
+type HttpClient interface {
+	// Do is an interface of http client Do method,
+	// that sends an HTTP request and returns an HTTP response.
+	Do(req *http.Request) (*http.Response, error)
+
+	// PostForm is an interface of http client PostForm method,
+	// that issues a POST to the specified URL.
+	PostForm(url string, data url.Values) (resp *http.Response, err error)
+}
+
+// Kiali Client
+type Client struct {
+	Strategy     Strategy
+	cache        cache.Interface
+	client       HttpClient
+	ServiceToken string
+	Host         string
+}
+
+// NewClient creates an instance of Kiali Client.
+func NewClient(strategy Strategy,
+	cache cache.Interface,
+	client HttpClient,
+	serviceToken string,
+	host string) *Client {
+
+	return &Client{
+		Strategy:     strategy,
+		cache:        cache,
+		client:       client,
+		ServiceToken: serviceToken,
+		Host:         host,
+	}
+
+}
+
+// NewDefaultClient creates an instance of Kiali Client with default http settings.
+func NewDefaultClient(
+	cache cache.Interface,
+	serviceToken string,
+	host string) *Client {
+	return &Client{
+		Strategy:     AuthStrategyToken,
+		cache:        cache,
+		client:       &http.Client{},
+		ServiceToken: serviceToken,
+		Host:         host,
+	}
+}
+
+// authenticate sends auth request with Kubernetes token and
+// get Kiali token from the response.
+func (c *Client) authenticate() (*TokenResponse, error) {
+	resp, err := c.client.PostForm(fmt.Sprintf(AuthURL, c.Host), url.Values{
+		"token": {c.ServiceToken},
+	})
+	if err != nil {
+		return nil, err
+	}
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	token := TokenResponse{}
+	err = json.Unmarshal(body, &token)
+	if err != nil {
+		return nil, err
+	}
+
+	return &token, nil
+}
+
+// Get issues a GET to the Kiali server with the url.
+func (c *Client) Get(url string) (resp *http.Response, err error) {
+
+	if req, err := http.NewRequest(http.MethodGet, fmt.Sprintf("%s%s", c.Host, url), nil); err != nil {
+		return nil, err
+	} else {
+		if c.Strategy == AuthStrategyToken {
+			err := c.SetToken(req)
+			if err != nil {
+				return nil, err
+			}
+		}
+		resp, err := c.client.Do(req)
+
+		if err != nil {
+			c.clearTokenCache(err)
+		}
+
+		return resp, err
+	}
+}
+
+func (c *Client) clearTokenCache(err error) {
+	if c.cache != nil && err != nil {
+		c.cache.Del(KialiTokenCacheKey)
+	}
+}
+
+// SetToken gets token from the Kiali server/cache and sets Bearer token to the request header.
+func (c *Client) SetToken(req *http.Request) error {
+	if c.cache != nil {
+		token, err := c.cache.Get(KialiTokenCacheKey)
+		if err == nil {
+			req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
+			return nil
+		}
+	}
+
+	token, err := c.authenticate()
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token.Token))
+
+	if c.cache != nil {
+		c.cache.Set(KialiTokenCacheKey, token.Token, time.Hour)
+	}
+	return nil
+}