Skywalking分布式链路追踪对Spring cloud Gateway无法记录链路问题记录

前因

最近在与技术进行链路验证，在测试Gateway服务一直无法加载显示，其他业务正常展示链路信息。

解决

如果你要追踪Gateway的话，你会发现：无法通过gateway发现路由的服务链路？

通过查看官方文档，原因： Spring Cloud Gateway 是基于 WebFlux 实现，必须搭配上apm-spring-cloud-gateway-2.1.x-plugin 和 apm-spring-webflux-x.x-plugin两个插件。

由于 SkyWalking 对于 spring-cloud-gateway 的支持不是默认的，所以需要将 agent/optional-plugins/上的几个插件复制到 agent/plugins 下，然后重启即可。

由此可见，agent，是通过加载，一系列的plugins插件，来帮我们干活。

最后

SkyWalking 上面这两个功能就已经非常强大，能够有效帮助我们优化我们的程序，监控系统的问题，并及时报警。

附上基于K8s部署的gateway

apiVersion: apps/v1
kind: Deployment
metadata:
  name: gateway
  namespace: ftintserv
  labels:
    app: gateway
spec:
  replicas: 1
  selector:
    matchLabels:
      app: gateway
  strategy:
    rollingUpdate:
      maxSurge: 70%
      maxUnavailable: 30%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: gateway
    spec:
      terminationGracePeriodSeconds: 60
      initContainers:
        - name: agent-container
          imagePullPolicy: IfNotPresent
          image: reg-hub.gzeport.com/library/apache/skywalking-java-agent:9.2.0-alpine
          volumeMounts:
            - mountPath: /agent
              name: skywalking-agent
          command:
            - "/bin/sh"
            - "-c"
            - "set -ex;cp -r /skywalking/agent /agent/;cp /skywalking/agent/optional-plugins/apm-spring-cloud-gateway* /agent/agent/plugins/;cp /skywalking/agent/optional-plugins/apm-spring-webflux* /agent/agent/plugins/;"
#          args: [ "-c","cp -R /skywalking/agent /agent/ " ]cp /skywalking/agent/optional-plugins/ /agent/plugins
          resources:
            requests:
              cpu: 0.2
              memory: 200Mi
            limits:
              cpu: 0.2
              memory: 200Mi
      containers:
        - name: gateway
          image: reg-hub.gzeport.com/ftintserv/gateway:1.0.1.RELEASE
          imagePullPolicy: Always
          ports:
            - containerPort: 8081
          env:
            - name: JAVA_SERVICE_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.labels['app']
            - name: JAVA_SERVICE_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
            - name: JAVA_OPTS
              value: "-Xms128m -Xmx512m -XX:MetaspaceSize=256M -XX:MaxMetaspaceSize=256M -Dspring.profiles.active=prod"
            - name: TZ
              value: "Asia/Shanghai"
            - name: AGENT_ARGS
              value: "-javaagent:/AppHome/skywalking-agent/agent/skywalking-agent.jar"
            - name: SW_AGENT_COLLECTOR_BACKEND_SERVICES
              value: skywalking-oap.logging.svc.cluster.local:11800
            - name: SW_AGENT_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.labels['app']
            - name: SW_AGENT_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
            - name: SW_LOGGING_LEVEL
              value: ERROR
            - name: SW_LOGGING_DIR
              value: /AppHome/logs/skywalking-agent
#          ### 启动探针
#          startupProbe:
#            httpGet:
#              port: 8081
#              path: /actuator/health/ping
#            initialDelaySeconds: 300
#            failureThreshold: 30
#            periodSeconds: 30
#          ### 就绪探针
#          readinessProbe:
#            httpGet:
#              port: 8081
#              path: /actuator/health/ping
#            initialDelaySeconds: 30  # 第一次执行探针前等待的时间
#            periodSeconds: 30  # 每隔多少秒执行一次
#            failureThreshold: 5
#          ### 存活探针
#          livenessProbe:
#            httpGet:
#              port: 8081
#              path: /actuator/health/ping
#            initialDelaySeconds: 30
#            periodSeconds: 30
#            failureThreshold: 3
#            timeoutSeconds: 5
          resources:
            requests:
              cpu: 0.5
              memory: 512Mi
            limits:
              cpu: 1
              memory: 1024Mi
          volumeMounts:
            - mountPath: /etc/localtime
              name: localtime
            - mountPath: /AppHome/logs
              subPath: gateway
              name: ftintserv-log-data
            - mountPath: /AppHome/skywalking-agent
              name: skywalking-agent
      volumes:
        - name: localtime
          hostPath:
            path: /etc/localtime
        - name: ftintserv-log-data
          persistentVolumeClaim:
            claimName: ftintserv-log-data-pvc
        - name: skywalking-agent
          emptyDir: { }
---
apiVersion: v1
kind: Service
metadata:
  name: ftintserv-gateway-svc
  namespace: ftintserv
spec:
  type: ClusterIP
  ports:
    - port: 8081
      protocol: TCP
      targetPort: 8081
  selector:
    app: gateway