Service Mesh之Istio部署bookinfo
我们在安装istio以后，对应会在k8s上创建一些crd资源，这些crd资源就是用来定义如何管控流量的；即我们通过定义这些crd类型的资源来告诉istiod,对应服务该如何暴露；只要我们在k8s集群上创建这些crd类型的资源以后，对应istiod就会将其收集起来，把对应资源转换为envoy的配置文件格式，再统一下发给通过istio注入的sidecar，以实现配置envoy的目的（envoy就是istio注入到应用pod中的sidecar）；
前文我们了解了service mesh、分布式服务治理和istio部署相关话题，回顾请参考https://www.cnblogs.com/qiuhom-1874/p/17281541.html；今天我们在istio环境中部署官方示例项目bookinfo；通过部署bookinfo项目来了解istio；
给istio部署插件
root@k8s-master01:/usr/local# cd istio root@k8s-master01:/usr/local/istio# ls samples/addons/ extras grafana.yaml jaeger.yaml kiali.yaml prometheus.yaml README.md root@k8s-master01:/usr/local/istio# kubectl apply -f samples/addons/ serviceaccount/grafana created configmap/grafana created service/grafana created deployment.apps/grafana created configmap/istio-grafana-dashboards created configmap/istio-services-grafana-dashboards created deployment.apps/jaeger created service/tracing created service/zipkin created service/jaeger-collector created serviceaccount/kiali created configmap/kiali created clusterrole.rbac.authorization.k8s.io/kiali-viewer created clusterrole.rbac.authorization.k8s.io/kiali created clusterrolebinding.rbac.authorization.k8s.io/kiali created role.rbac.authorization.k8s.io/kiali-controlplane created rolebinding.rbac.authorization.k8s.io/kiali-controlplane created service/kiali created deployment.apps/kiali created serviceaccount/prometheus created configmap/prometheus created clusterrole.rbac.authorization.k8s.io/prometheus created clusterrolebinding.rbac.authorization.k8s.io/prometheus created service/prometheus created deployment.apps/prometheus created root@k8s-master01:/usr/local/istio#
提示：istio插件的部署清单在istio/samples/addons/目录下，该目录下有grafana、jaeger、kiali、prometheus的部署清单；其中jaeger是负责链路追踪，kiali是istio的一个web客户端工具，我们可以在web页面来管控istio，prometheus是负责指标数据采集，grafana负责指标数据的展示工具；应用该目录下的所有部署清单后，对应istio-system名称空间下会跑相应的pod和相应的svc资源;
验证：在istio-system名称空间下，查看对应pod是否正常跑起来了？对应svc资源是否创建？
root@k8s-master01:/usr/local/istio# kubectl get pods -n istio-system NAME READY STATUS RESTARTS AGE grafana-69f9b6bfdc-cm966 1/1 Running 0 12m istio-egressgateway-774d6846df-fv97t 1/1 Running 3 (144m ago) 22h istio-ingressgateway-69499dc-pdgld 1/1 Running 3 (144m ago) 22h istiod-65dcb8497-9skn9 1/1 Running 3 (145m ago) 22h jaeger-cc4688b98-wzfph 1/1 Running 0 12m kiali-594965b98c-kbllg 1/1 Running 0 64s prometheus-5f84bbfcfd-62nwc 2/2 Running 0 12m root@k8s-master01:/usr/local/istio# kubectl get svc -n istio-system NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE grafana ClusterIP 10.107.10.186 <none> 3000/TCP 12m istio-egressgateway ClusterIP 10.106.179.126 <none> 80/TCP,443/TCP 22h istio-ingressgateway LoadBalancer 10.102.211.120 192.168.0.252 15021:32639/TCP,80:31338/TCP,443:30597/TCP,31400:31714/TCP,15443:32154/TCP 22h istiod ClusterIP 10.96.6.69 <none> 15010/TCP,15012/TCP,443/TCP,15014/TCP 22h jaeger-collector ClusterIP 10.100.138.187 <none> 14268/TCP,14250/TCP,9411/TCP 12m kiali ClusterIP 10.99.88.50 <none> 20001/TCP,9090/TCP 12m prometheus ClusterIP 10.108.131.84 <none> 9090/TCP 12m tracing ClusterIP 10.100.53.36 <none> 80/TCP,16685/TCP 12m zipkin ClusterIP 10.110.231.233 <none> 9411/TCP 12m root@k8s-master01:/usr/local/istio#
提示：可以看到对应pod都在正常runing并处于ready状态；对应svc资源也都正常创建；我们要想访问对应服务，可以在集群内部访问对应的clusterIP来访问；也可以修改svc对应资源类型为nodeport或者loadbalancer类型；当然除了上述修改svc资源类型的方式实现集群外部访问之外，我们也可以通过istio的入口网关来访问；不过这种方式需要我们先通过配置文件告诉给istiod，让其把对应的服务通过ingressgate的外部IP地址暴露出来；
这里说一下通过ingressgateway暴露服务的原理；我们在安装istio以后，对应会在k8s上创建一些crd资源，这些crd资源就是用来定义如何管控流量的；即我们通过定义这些crd类型的资源来告诉istiod,对应服务该如何暴露；只要我们在k8s集群上创建这些crd类型的资源以后，对应istiod就会将其收集起来，把对应资源转换为envoy的配置文件格式，再统一下发给通过istio注入的sidecar，以实现配置envoy的目的（envoy就是istio注入到应用pod中的sidecar）；
查看crd
root@k8s-master01:~# kubectl get crds NAME CREATED AT authorizationpolicies.security.istio.io 2023-04-02T16:28:24Z bgpconfigurations.crd.projectcalico.org 2023-04-02T02:26:34Z bgppeers.crd.projectcalico.org 2023-04-02T02:26:34Z blockaffinities.crd.projectcalico.org 2023-04-02T02:26:34Z caliconodestatuses.crd.projectcalico.org 2023-04-02T02:26:34Z clusterinformations.crd.projectcalico.org 2023-04-02T02:26:34Z destinationrules.networking.istio.io 2023-04-02T16:28:24Z envoyfilters.networking.istio.io 2023-04-02T16:28:24Z felixconfigurations.crd.projectcalico.org 2023-04-02T02:26:34Z gateways.networking.istio.io 2023-04-02T16:28:24Z globalnetworkpolicies.crd.projectcalico.org 2023-04-02T02:26:34Z globalnetworksets.crd.projectcalico.org 2023-04-02T02:26:34Z hostendpoints.crd.projectcalico.org 2023-04-02T02:26:34Z ipamblocks.crd.projectcalico.org 2023-04-02T02:26:34Z ipamconfigs.crd.projectcalico.org 2023-04-02T02:26:34Z ipamhandles.crd.projectcalico.org 2023-04-02T02:26:34Z ippools.crd.projectcalico.org 2023-04-02T02:26:34Z ipreservations.crd.projectcalico.org 2023-04-02T02:26:34Z istiooperators.install.istio.io 2023-04-02T16:28:24Z kubecontrollersconfigurations.crd.projectcalico.org 2023-04-02T02:26:34Z networkpolicies.crd.projectcalico.org 2023-04-02T02:26:34Z networksets.crd.projectcalico.org 2023-04-02T02:26:34Z peerauthentications.security.istio.io 2023-04-02T16:28:24Z proxyconfigs.networking.istio.io 2023-04-02T16:28:24Z requestauthentications.security.istio.io 2023-04-02T16:28:24Z serviceentries.networking.istio.io 2023-04-02T16:28:24Z sidecars.networking.istio.io 2023-04-02T16:28:24Z telemetries.telemetry.istio.io 2023-04-02T16:28:24Z virtualservices.networking.istio.io 2023-04-02T16:28:24Z wasmplugins.extensions.istio.io 2023-04-02T16:28:24Z workloadentries.networking.istio.io 2023-04-02T16:28:24Z workloadgroups.networking.istio.io 2023-04-02T16:28:24Z root@k8s-master01:~# kubectl api-resources --api-group=networking.istio.io NAME SHORTNAMES APIVERSION NAMESPACED KIND destinationrules dr networking.istio.io/v1beta1 true DestinationRule envoyfilters networking.istio.io/v1alpha3 true EnvoyFilter gateways gw networking.istio.io/v1beta1 true Gateway proxyconfigs networking.istio.io/v1beta1 true ProxyConfig serviceentries se networking.istio.io/v1beta1 true ServiceEntry sidecars networking.istio.io/v1beta1 true Sidecar virtualservices vs networking.istio.io/v1beta1 true VirtualService workloadentries we networking.istio.io/v1beta1 true WorkloadEntry workloadgroups wg networking.istio.io/v1beta1 true WorkloadGroup root@k8s-master01:~#
提示：可以看到在networking.istio.io这个群组里面有很多crd资源类型；其中gateway就是来定义如何接入外部流量的；virtualservice就是来定义虚拟主机的（类似apache中的虚拟主机），destinationrules用于定义外部流量通过gateway进来以后，结合virtualservice路由，对应目标该如何承接对应流量的；我们在k8s集群上创建这些类型的crd资源以后，都会被istiod收集并由它负责将其转换为envoy识别的格式配置统一下发给整个网格内所有的envoy sidecar或istio-system名称空间下所有envoy pod;
通过istio ingressgateway暴露kiali服务
定义 kiali-gateway资源实现流量匹配
# cat kiali-gateway.yaml
apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
name: kiali-gateway
namespace: istio-system
spec:
selector:
app: istio-ingressgateway
servers:
- port:
number: 80
name: http-kiali
protocol: HTTP
hosts:
- "kiali.ik8s.cc"
提示：该资源定义了通过istio-ingresstateway进来的流量，匹配主机头为kiali.ik8s.cc，协议为http,端口为80的流量；
定义virtualservice资源实现路由
# cat kiali-virtualservice.yaml
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
name: kiali-virtualservice
namespace: istio-system
spec:
hosts:
- "kiali.ik8s.cc"
gateways:
- kiali-gateway
http:
- match:
- uri:
prefix: /
route:
- destination:
host: kiali
port:
number: 20001
提示：该资源定义了gateway进来的流量匹配主机头为kiali.ik8s.cc，uri匹配“/”；就把对应流量路由至对应服务名为kiali的服务的20001端口进行响应；
定义destinationrule实现如何承接对应流量
# cat kiali-destinationrule.yaml
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
name: kiali
namespace: istio-system
spec:
host: kiali
trafficPolicy:
tls:
mode: DISABLE
提示：该资源定义了对应承接非tls的流量；即关闭kiali服务的tls功能；
应用上述配置清单
root@k8s-master01:~/istio-in-practise/Traffic-Management-Basics/kiali-port-80# kubectl apply -f . destinationrule.networking.istio.io/kiali created gateway.networking.istio.io/kiali-gateway created virtualservice.networking.istio.io/kiali-virtualservice created root@k8s-master01:~/istio-in-practise/Traffic-Management-Basics/kiali-port-80# kubectl get gw -n istio-system NAME AGE kiali-gateway 27s root@k8s-master01:~/istio-in-practise/Traffic-Management-Basics/kiali-port-80# kubectl get vs -n istio-system NAME GATEWAYS HOSTS AGE kiali-virtualservice ["kiali-gateway"] ["kiali.ik8s.cc"] 33s root@k8s-master01:~/istio-in-practise/Traffic-Management-Basics/kiali-port-80# kubectl get dr -n istio-system NAME HOST AGE kiali kiali 38s root@k8s-master01:~/istio-in-practise/Traffic-Management-Basics/kiali-port-80#
通过集群外部客户端的hosts文件将kiali.ik8s.cc解析至istio-ingressgateway外部地址
提示：我这里是一台win11的客户端，修改C:\Windows\System32\drivers\etc\hosts文件来实现解析；
测试，用浏览器访问kiali.ik8s.cc看看对应是否能够访问到kiali服务呢？
提示：可以看到我们现在就把集群内部kiali服务通过gateway、virtualservice、destinationrule这三种资源的创建将其暴露给ingresgateway的外部地址上；对于其他服务我们也可以采用类似的逻辑将其暴露出来；这里建议kiali不要直接暴露给集群外部客户端访问，因为kiali没有认证，但它又具有管理istio的功能；
部署bookinfo
root@k8s-master01:/usr/local/istio# kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml service/details created serviceaccount/bookinfo-details created deployment.apps/details-v1 created service/ratings created serviceaccount/bookinfo-ratings created deployment.apps/ratings-v1 created service/reviews created serviceaccount/bookinfo-reviews created deployment.apps/reviews-v1 created deployment.apps/reviews-v2 created deployment.apps/reviews-v3 created service/productpage created serviceaccount/bookinfo-productpage created deployment.apps/productpage-v1 created root@k8s-master01:/usr/local/istio#
提示：我们安装istio以后，bookinfo的部署清单就在istio/samples/bookinfo/platform/kube/目录下；该部署清单会在default名称空间将bookinfo需要的pod运行起来，并创建相应的svc资源；
验证：查看default名称空间下的pod和svc资源，看看对应pod和svc是否正常创建？
root@k8s-master01:/usr/local/istio# kubectl get pods NAME READY STATUS RESTARTS AGE details-v1-6997d94bb9-4jssp 2/2 Running 0 2m56s productpage-v1-d4f8dfd97-z2pcz 2/2 Running 0 2m55s ratings-v1-b8f8fcf49-j8l44 2/2 Running 0 2m56s reviews-v1-5896f547f5-v2h92 2/2 Running 0 2m56s reviews-v2-5d99885bc9-dhjdk 2/2 Running 0 2m55s reviews-v3-589cb4d56c-rw6rw 2/2 Running 0 2m55s root@k8s-master01:/usr/local/istio# kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE details ClusterIP 10.109.96.34 <none> 9080/TCP 3m2s kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 38h productpage ClusterIP 10.101.76.112 <none> 9080/TCP 3m1s ratings ClusterIP 10.97.209.163 <none> 9080/TCP 3m2s reviews ClusterIP 10.108.1.117 <none> 9080/TCP 3m2s root@k8s-master01:/usr/local/istio#
提示：可以看到default名称空间下跑了几个pod，每个pod内部都有两个容器，其中一个是bookinfo程序的主容器，一个是istio注入的sidecar;bookinfo的访问入口是productpage；
验证：查看istiod是否将配置下发给我们刚才部署的bookinfo中注入的sidecar配置？
root@k8s-master01:/usr/local/istio# istioctl ps NAME CLUSTER CDS LDS EDS RDS ECDS ISTIOD VERSION details-v1-6997d94bb9-4jssp.default Kubernetes SYNCED SYNCED SYNCED SYNCED NOT SENT istiod-65dcb8497-9skn9 1.17.1 istio-egressgateway-774d6846df-fv97t.istio-system Kubernetes SYNCED SYNCED SYNCED NOT SENT NOT SENT istiod-65dcb8497-9skn9 1.17.1 istio-ingressgateway-69499dc-pdgld.istio-system Kubernetes SYNCED SYNCED SYNCED SYNCED NOT SENT istiod-65dcb8497-9skn9 1.17.1 productpage-v1-d4f8dfd97-z2pcz.default Kubernetes SYNCED SYNCED SYNCED SYNCED NOT SENT istiod-65dcb8497-9skn9 1.17.1 ratings-v1-b8f8fcf49-j8l44.default Kubernetes SYNCED SYNCED SYNCED SYNCED NOT SENT istiod-65dcb8497-9skn9 1.17.1 reviews-v1-5896f547f5-v2h92.default Kubernetes SYNCED SYNCED SYNCED SYNCED NOT SENT istiod-65dcb8497-9skn9 1.17.1 reviews-v2-5d99885bc9-dhjdk.default Kubernetes SYNCED SYNCED SYNCED SYNCED NOT SENT istiod-65dcb8497-9skn9 1.17.1 reviews-v3-589cb4d56c-rw6rw.default Kubernetes SYNCED SYNCED SYNCED SYNCED NOT SENT istiod-65dcb8497-9skn9 1.17.1 root@k8s-master01:/usr/local/istio#
提示：这里我们只需要关心cds、lds、eds、rds即可；显示synced表示对应配置已经下发；配置下发完成以后，对应服务就可以在集群内部访问了；
验证：在集群内部部署一个客户端pod，访问productpage：9080看看对应bookinfo是否被访问到？
root@k8s-master01:/usr/local/istio# kubectl apply -f samples/sleep/sleep.yaml serviceaccount/sleep created service/sleep created deployment.apps/sleep created root@k8s-master01:/usr/local/istio# kubectl get pods NAME READY STATUS RESTARTS AGE details-v1-6997d94bb9-4jssp 2/2 Running 0 12m productpage-v1-d4f8dfd97-z2pcz 2/2 Running 0 12m ratings-v1-b8f8fcf49-j8l44 2/2 Running 0 12m reviews-v1-5896f547f5-v2h92 2/2 Running 0 12m reviews-v2-5d99885bc9-dhjdk 2/2 Running 0 12m reviews-v3-589cb4d56c-rw6rw 2/2 Running 0 12m sleep-bc9998558-vjc48 2/2 Running 0 50s root@k8s-master01:/usr/local/istio#
进入sleep pod，访问productpage：9080看看是否能访问？
root@k8s-master01:/usr/local/istio# kubectl exec -it sleep-bc9998558-vjc48 -- /bin/sh
/ $ cd
~ $ curl productpage:9080
<!DOCTYPE html>
<html>
<head>
<title>Simple Bookstore App</title>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- Latest compiled and minified CSS -->
<link rel="stylesheet" href="static/bootstrap/css/bootstrap.min.css">
<!-- Optional theme -->
<link rel="stylesheet" href="static/bootstrap/css/bootstrap-theme.min.css">
</head>
<body>
<p>
<h3>Hello! This is a simple bookstore application consisting of three services as shown below</h3>
</p>
<table class="table table-condensed table-bordered table-hover"><tr><th>name</th><td>http://details:9080</td></tr><tr><th>endpoint</th><td>details</td></tr><tr><th>children</th><td><table class="table table-condensed table-bordered table-hover"><tr><th>name</th><th>endpoint</th><th>children</th></tr><tr><td>http://details:9080</td><td>details</td><td></td></tr><tr><td>http://reviews:9080</td><td>reviews</td><td><table class="table table-condensed table-bordered table-hover"><tr><th>name</th><th>endpoint</th><th>children</th></tr><tr><td>http://ratings:9080</td><td>ratings</td><td></td></tr></table></td></tr></table></td></tr></table>
<p>
<h4>Click on one of the links below to auto generate a request to the backend as a real user or a tester
</h4>
</p>
<p><a href="/productpage?u=normal">Normal user</a></p>
<p><a href="/productpage?u=test">Test user</a></p>
<!-- Latest compiled and minified JavaScript -->
<script src="static/jquery.min.js"></script>
<!-- Latest compiled and minified JavaScript -->
<script src="static/bootstrap/js/bootstrap.min.js"></script>
</body>
</html>
~ $
提示：可以看到对应客户端pod能够正常访问productpage：9080；这里说一下我们在集群内部pod中用productpage来访问服务是可以正常被coredns解析到对应svc上进行响应的；
暴露bookinfo给集群外部客户端访问
root@k8s-master01:~# cat /usr/local/istio/samples/bookinfo/networking/bookinfo-gateway.yaml
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: bookinfo-gateway
spec:
selector:
istio: ingressgateway # use istio default controller
servers:
- port:
number: 80
name: http
protocol: HTTP
hosts:
- "*"
---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: bookinfo
spec:
hosts:
- "*"
gateways:
- bookinfo-gateway
http:
- match:
- uri:
exact: /productpage
- uri:
prefix: /static
- uri:
exact: /login
- uri:
exact: /logout
- uri:
prefix: /api/v1/products
route:
- destination:
host: productpage
port:
number: 9080
root@k8s-master01:~#
提示：该清单将bookinfo通过关联ingressgateway的外部地址的80端口关联，所以我们访问ingressgateway的外部地址就可以访问到bookinfo；
应用清单
root@k8s-master01:~# kubectl apply -f /usr/local/istio/samples/bookinfo/networking/bookinfo-gateway.yaml gateway.networking.istio.io/bookinfo-gateway created virtualservice.networking.istio.io/bookinfo created root@k8s-master01:~#
验证：访问ingressgateway的外部地址，看看对应bookinfo是否能够被访问到？
提示：可以看到现在我们在集群外部通过访问ingressgateway的外部地址就能正常访问到bookinfo,通过多次访问，还可以实现不同的效果；
模拟客户端访问bookinfo
root@k8s-node03:~# while true ; do curl 192.168.0.252/productpage;sleep 0.$RANDOM;done
在kiali上查看绘图
提示：我们在kiali上看到的图形，就是通过模拟客户端访问流量所形成的图形；该图形能够形象的展示对应服务流量的top,以及动态显示对应流量访问应用的比例；我们可以通过定义配置文件的方式，动态调整客户端能够访问到bookinfo那个版本；对应绘图也会通过采集到的指标数据动态将流量路径绘制出来；
通过bookinfo测试流量治理功能
创建destinationrule
root@k8s-master01:/usr/local/istio# cat samples/bookinfo/networking/destination-rule-all.yaml
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: productpage
spec:
host: productpage
subsets:
- name: v1
labels:
version: v1
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: reviews
spec:
host: reviews
subsets:
- name: v1
labels:
version: v1
- name: v2
labels:
version: v2
- name: v3
labels:
version: v3
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: ratings
spec:
host: ratings
subsets:
- name: v1
labels:
version: v1
- name: v2
labels:
version: v2
- name: v2-mysql
labels:
version: v2-mysql
- name: v2-mysql-vm
labels:
version: v2-mysql-vm
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: details
spec:
host: details
subsets:
- name: v1
labels:
version: v1
- name: v2
labels:
version: v2
---
root@k8s-master01:/usr/local/istio#
提示：上述清单主要定义了不同版本对应的服务的版本；
应用清单
root@k8s-master01:/usr/local/istio# kubectl apply -f samples/bookinfo/networking/destination-rule-all.yaml destinationrule.networking.istio.io/productpage created destinationrule.networking.istio.io/reviews created destinationrule.networking.istio.io/ratings created destinationrule.networking.istio.io/details created root@k8s-master01:/usr/local/istio#
将所有流量路由至v1版本
root@k8s-master01:/usr/local/istio# kubectl apply -f samples/bookinfo/networking/virtual-service-all-v1.yaml virtualservice.networking.istio.io/productpage created virtualservice.networking.istio.io/reviews created virtualservice.networking.istio.io/ratings created virtualservice.networking.istio.io/details created root@k8s-master01:/usr/local/istio#
验证：在kiali上查看对应流量是否只有v1版本了？
提示：可以看到现在kiali绘制的图里面就只有v1版本的流量，其他v2，v3版本流量就没有了；
通过客户端登陆身份标识来路由
root@k8s-master01:/usr/local/istio# cat samples/bookinfo/networking/virtual-service-reviews-test-v2.yaml
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: reviews
spec:
hosts:
- reviews
http:
- match:
- headers:
end-user:
exact: jason
route:
- destination:
host: reviews
subset: v2
- route:
- destination:
host: reviews
subset: v1
root@k8s-master01:/usr/local/istio#
提示：上述清单定义了，登录用户名为jason，就响应v2版本；其他未登录的客户端还是以v1版本响应；
验证：应用配置清单，登录jason，看看是否是以v2版本响应？
提示：可以看到我们应用了配置清单以后，对应模拟客户端访问的还是一直以v1的版本响应；我们登录jason用户以后，对应响应给我们的页面就是v2版本，退出jason用户又是以v1版本响应；
以上就是bookinfo在istio服务网格中，通过定义不同的配置，实现高级流量治理的效果；
作者：Linux-1874
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利.
