问题现象
在带有 istio-injection: enabled 标签的命名空间中部署服务，服务无法通过 X-Forwarded-For 获取客户端真实 IP。
解决方法
升级 Istio
检查并升级 Istio 版本到 1.7 以上。
设置 externalTrafficPolicy
设置 externalTrafficPolicy 为 Local。
apiVersion: install.istio.io/v1alpha1
kind: IstioOperator
metadata:
namespace: istio-system
name: istiocontrolplane
spec:
profile: default
components:
ingressGateways:
- name: istio-ingressgateway
enabled: true
k8s:
service:
externalTrafficPolicy: Local
等待 ingressgateway 重新部署完成。
下面，部署 httpbin 服务作为验证。
# httpbin.yaml
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: httpbin
spec:
hosts:
- "httpbin.makeoptim.com"
gateways:
- gateway/makeoptim-gateway
http:
- route:
- destination:
port:
number: 8000
host: httpbin
---
apiVersion: v1
kind: Service
metadata:
name: httpbin
labels:
app: httpbin
spec:
ports:
- name: http
port: 8000
selector:
app: httpbin
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: httpbin
spec:
replicas: 1
selector:
matchLabels:
app: httpbin
version: v1
template:
metadata:
labels:
app: httpbin
version: v1
spec:
containers:
- image: docker.io/citizenstig/httpbin
imagePullPolicy: IfNotPresent
name: httpbin
ports:
- containerPort: 8000
部署完 httpbin 后，直接访问并查看 Headers，可以看到多了一项 X-Envoy-External-Address Header，并且指向客户端真实 IP。
❯ curl httpbin.makeoptim.com/get
{
"args": {},
"headers": {
"Accept": "*/*",
"Content-Length": "0",
"Host": "httpbin.makeoptim.com",
"User-Agent": "curl/7.64.1",
"X-B3-Parentspanid": "50419cd0b3ae983a",
"X-B3-Sampled": "0",
"X-B3-Spanid": "5a0bbd2e611fa59e",
"X-B3-Traceid": "33c8c481a13746c050419cd0b3ae983a",
"X-Envoy-Attempt-Count": "1",
"X-Envoy-External-Address": "38.75.137.213",
"X-Forwarded-Client-Cert": "By=spiffe://cluster.local/ns/default/sa/default;Hash=abb1a2a76a04fe7476cd38738e98a228b39dbf6a88936fd249ee23839ec98234;Subject=\"\";URI=spiffe://cluster.local/ns/istio-system/sa/istio-ingressgateway-service-account",
"X-Request-Id": "2fe85688-cf60-4f61-b9bb-25e354625124"
},
"origin": "38.75.137.213",
"url": "http://httpbin.makeoptim.com/get"
}
在自己的服务中，即可通过 X-Envoy-External-Address 来获取客户端真实 IP，下面以 Golang 代码为例：
package http
import "net/http"
var clientIPHeaders = []string{"X-Envoy-External-Address", "X-Forwarded-For", "X-Real-Ip", "X-Appengine-Remote-Addr"}
// ClientIP get client IP with possible headers.
func ClientIP(request *http.Request) string {
for _, v := range clientIPHeaders {
ip := request.Header.Get(v)
if ip != "" {
return ip
}
}
return ""
}
