istio環境集成zipkin

   在非istio的環境中，如果我們選擇了zipkin作為鏈路追蹤的解決方案，那么我們需要業務代碼里對每次調用生成span/trace id,雖然大部分流行語言zipkin都提供了對應的sdk幫我們做了這些集成工作，但是我們還是要在發出請求時手動調用sdk提供的方法生成並攜帶相應header到業務下游，相當於要對每一種語言都要去手動做一次 request的封裝，如果公司使用的語言多了那么會是一種很繁瑣的工作。那么有沒有一種工具能幫我們自動生成每次調用所需的信息呢? 答案當然是有的，在istio環境中，這一切都變成了可能、當envoy收到調用請求時，會自動幫我們注入所需的headers，在業務代碼中我們只需做少量改動，只需要調用下游服務時傳遞header 就可以了。參考地址：https://istio.io/latest/zh/docs/tasks/observability/distributed-tracing/overview/

 

下面是一個python flask 應用在istio中接入zipkin的例子：

1.拓撲：

有三個應用，分別是 zipkin-a ， zipkin-b， zipkin-c

調用關系是: zipkin-a  ----->  zipkin-b ----> zipkin-c

案例代碼：

zipkin-a:

from flask import Flask,request
import requests

app = Flask(__name__)


@app.route('/')
def hello_worlda():
    tmp_headers = {}
    b3_headers = ["x-request-id","x-b3-traceid","x-b3-spanid","x-b3-parentspanid","x-b3-sampled","x-b3-flags","x-ot-span-context"]
    for header in b3_headers:
        if request.headers.get(header):
            tmp_headers.update({header:request.headers.get(header)})
    requests.get('http://zipkin-b:5001',headers=tmp_headers)
    return 'zipkin-a!'


if __name__ == '__main__':
    app.run(host="0.0.0.0",port=5000)

zipkin-b:

from flask import Flask,request
import requests

app = Flask(__name__)


@app.route('/')
def hello_worlda():
    tmp_headers = {}
    b3_headers = ["x-request-id","x-b3-traceid","x-b3-spanid","x-b3-parentspanid","x-b3-sampled","x-b3-flags","x-ot-span-context"]
    for header in b3_headers:
        if request.headers.get(header):
            tmp_headers.update({header:request.headers.get(header)})
    requests.get('http://zipkin-c:5002', headers=tmp_headers)
    return 'zipkin-b'


if __name__ == '__main__':
    app.run(host="0.0.0.0",port=5001)

zipkin-c:

from flask import Flask,request

app = Flask(__name__)


@app.route('/')
def hello_world():
    print(' ------------- ^^^ -----------')
    print(request.headers)
    return 'Hello World!'


if __name__ == '__main__':
    app.run(host="0.0.0.0",port=5002)

 

對應k8s manifest:

zipkin-a:

kind: Deployment
metadata:
 name: zipkin-a
spec:
 selector:
  matchLabels:
    app: zipkin-a
    version: "v1"
 replicas: 1
 template:
  metadata:
   labels:
    app: zipkin-a
    version: "v1"
  spec:
   containers:
   - name: zipkin-a
     image: reg.xthklocal.cn/xthk-library/zipkin_a
     command: ["python","/tmp/a.py"]
     ports:
     - containerPort: 5000
       name: http
       protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: zipkin-a
spec:
  ports:
  - name: http-5000
    port: 5000
    protocol: TCP
    targetPort: 5000
  selector:
    app: zipkin-a
  type: ClusterIP

 

zipkin-b:

apiVersion: apps/v1
kind: Deployment
metadata:
 name: zipkin-b
spec:
 selector:
  matchLabels:
    app: zipkin-b
    version: "v1"
 replicas: 1
 template:
  metadata:
   labels:
    app: zipkin-b
    version: "v1"
  spec:
   containers:
   - name: zipkin-b
     image: reg.xthklocal.cn/xthk-library/zipkin_b
     command: ["python","/tmp/b.py"]
     ports:
     - containerPort: 5001
       name: http
       protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: zipkin-b
spec:
  ports:
  - name: http-5000
    port: 5001
    protocol: TCP
    targetPort: 5001
  selector:
    app: zipkin-b
  type: ClusterIP

zipkin-c:

apiVersion: apps/v1
kind: Deployment
metadata:
 name: zipkin-c
spec:
 selector:
  matchLabels:
    app: zipkin-c
    version: "v1"
 replicas: 1
 template:
  metadata:
   labels:
    app: zipkin-c
    version: "v1"
  spec:
   containers:
   - name: zipkin-c
     image: reg.xthklocal.cn/xthk-library/zipkin_c
     command: ["python","/tmp/c.py"]
     ports:
     - containerPort: 5002
       name: http
       protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: zipkin-c
spec:
  ports:
  - name: http-5000
    port: 5002
    protocol: TCP
    targetPort: 5002
  selector:
    app: zipkin-c
  type: ClusterIP

 

istio 增加以下zipkin 配置：

data:
  mesh: |-
    defaultConfig:
      tracing:
        zipkin:
          address: 192.168.3.100:31377   #改成zipkin server的實際地址

 

進入任意能與zipkin-a 容器通信的容器調用zipkin-a 服務觸發鏈路上報 （如果采樣率未設置未全部采樣，需要多次調用才能看到效果）

 

 

登錄zipkin查看效果