应用接入Skywalking

# 1、使用Skywalking Agent

Java 中使用 agent ，提供了以下三种方式供你选择

- 使用官方提供的基础镜像 skywalking-base; 
- 将 agent 包构建到已经存在的基础镜像中; 
- sidecar 模式挂载 agent(推荐);

**1、使用官方提供的基础镜像**

[Downloads | Apache SkyWalking](https://skywalking.apache.org/downloads/)

**2、将agent包构建到已经存在的基础镜像中**

提供这种方式的原因是:官方的镜像属于精简镜像，并且是 openjdk ，可能很多命令没有，需要自己二次安装，这里略过。

**3、sidecar模式挂载agent**

- 不需要修改原来的基础镜像，也无需重新构建服务镜像。以sidecar 模式，通过共享volume 的方式将 agent 所需的相关文件挂载到已经存在的服务镜像中。
- 在 Sidecar 模式下，SkyWalking 代理程序与应用程序是分离的，不会影响应用程序的执行，也不会干扰到应用的性能问题。

**4、构建skywalking agent image**

通过以下dockerfile进行构建

```dockerfile
FROM alpine:3.8

LABEL maintainer="ZHDYA"

ENV SKYWALKING_VERSION=8.5.0

ADD https://archive.apache.org/dist/skywalking/${SKYWALKING_VERSION}/apache-skywalking-apm-${SKYWALKING_VERSION}.tar.gz /

RUN tar -zxvf /apache-skywalking-apm-${SKYWALKING_VERSION}.tar.gz && \
    mv apache-skywalking-apm-bin skywalking && \
    mv /skywalking/agent/optional-plugins/apm-trace-ignore-plugin* /skywalking/agent/plugins/ && \
    sed -i 's@# logging.max_history_files=${SW_LOGGING_MAX_HISTORY_FILES:-1}@logging.max_history_files=${SW_LOGGING_MAX_HISTORY_FILES:2}@' /skywalking/agent/config/agent.config && \
    echo -e "\n# Ignore Path" >> /skywalking/agent/config/agent.config && \
    echo "# see https://github.com/apache/skywalking/blob/v8.5.0/docs/en/setup/service-agent/java-agent/agent-optional-plugins/trace-ignore-plugin.md" >> /skywalking/agent/config/agent.config && \
    echo 'trace.ignore_path=${SW_IGNORE_PATH:/health}' >> /skywalking/agent/config/agent.config
```

待 docker build 完毕后，push 到仓库即可。

```shell
$ docker build -t harbor-local.kubernets.cn/library/skywalking-agent:8.5.0 .

$ docker push harbor-local.kubernets.cn/library/skywalking-agent:8.5.0
```

**5、使用sidecar挂载**

测试 demo应用

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo-skywalking
spec:
  replicas: 1
  selector:
    matchLabels:
      app: demo-skywalking
  strategy:
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: demo-skywalking
    spec:
      initContainers:
        - name: init-skywalking-agent
          image: harbor-local.kubernets.cn/library/skywalking-agent:8.5.0
          command:
            - 'sh'
            - '-c'
            - 'set -ex;mkdir -p /vmskywalking/agent;cp -r /skywalking/agent/* /vmskywalking/agent;'
          volumeMounts:
            - mountPath: /vmskywalking/agent
              name: skywalking-agent
      containers:
        - image: nginx:1.7.9
          imagePullPolicy: Always
          name: nginx
          ports:
            - containerPort: 80
              protocol: TCP
          volumeMounts:
            - mountPath: /opt/skywalking/agent
              name: skywalking-agent
      volumes:
        - name: skywalking-agent
          emptyDir: {}
```

以上是挂载`sidecar`的`deployment.yaml`文件，以`nginx`作为服务为例，主要是通过 共享`volume`的方式挂载`agent`。

首先`initContainers`通过`skywalking-agent`卷挂载了`sw-agent-sidecar`中的`/vmskywalking/agent`，并且将上面构建好的镜像中的`agent`目录 cp 到了`/vmskywalking/agent`目录，完成之后`nginx`启动时也挂载了`skywalking-agent`卷，并将其挂载到了容器的`/opt/skywalking/agent`目录。

# 2、改造Spring Cloud应用

**1、docker打包并推送到仓库**

修改下 dockerfile 配置，集成 skywalking agent：

```dockerfile
# FROM openjdk:8-jdk
FROM harbor-local.kubernets.cn/library/openjdk:8-jdk
COPY ./springdemo2023.jar /opt/
RUN mkdir -p data/logs/ \
&& mkdir -p data/skywalking/agent
RUN ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
RUN echo 'Asia/Shanghai' > /etc/timezone

ENTRYPOINT [ "java","-Dapp.id=springdemo2023","-javaagent:/data/skywalking/agent/skywalking-agent.jar","-Dskywalking.agent.service_name=springdemo2023","-Dskywalking.collector.backend_service=skywalking-oap.devops.svc.cluster.local:11800", "-jar", "/opt/springdemo2023.jar" ,"-Dfile.encoding=UTF-8"]
```

注意:

> k8s 创建 Service 时，它会创建相应的 DNS 条目。此条目的格式为`<service-name>.<namespace-name>.svc.cludster.local`，这意味着如果容器只使用`<service-name>`，它将解析为本地服务到命名空间。 如果要跨命名空间访问，则 需要使用完全限定的域名。

编译推送到私仓测试:

```bash
$ docker build -t harbor-local.kubernets.cn/demo/springdemo-skywalking:v1 .
```

**2、编写 k8s的yaml部署**

```yaml
    apiVersion: v1
    kind: Service
    metadata:
      annotations:
        prometheus.io/http-probe: "true"
        prometheus.io/http-probe-port: "8080"
        prometheus.io/http-probe-path: "/apptwo"
      name: springdemo2023
      namespace: default
    spec:
      ports:
      - name: web
        port: 8080
        protocol: TCP
        targetPort: 8080
      selector:
        app: springdemo2023
      sessionAffinity: None
      type: ClusterIP
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: springdemo2023
      namespace: default
    spec:
      replicas: 1
      revisionHistoryLimit: 10
      selector:
        matchLabels:
          app: springdemo2023
      strategy:
        rollingUpdate:
          maxSurge: 25%
          maxUnavailable: 25%
        type: RollingUpdate
      template:
        metadata:
          labels:
            app: springdemo2023
        spec:
          imagePullSecrets:
          - name: harborsecret
          initContainers:
            - name: init-skywalking-agent
              image: harbor-local.kubernets.cn/library/skywalking-agent:8.5.0
              command:
                - 'sh'
                - '-c'
                - 'set -ex;mkdir -p /vmskywalking/agent;cp -r /skywalking/agent/* /vmskywalking/agent;'
              volumeMounts:
                - mountPath: /vmskywalking/agent
                  name: skywalking-agent
          containers:
          - image: harbor-local.kubernets.cn/demo/springdemo-skywalking:v1
            imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 5
          httpGet:
            path: /apptwo
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 30
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 2
        name: springdemo2023
        ports:
        - containerPort: 8080
          name: web
          protocol: TCP
        readinessProbe:
          failureThreshold: 5
          httpGet:
            path: /apptwo
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 20
          periodSeconds: 5
          successThreshold: 1
          timeoutSeconds: 2
        volumeMounts:
        - mountPath: /data/skywalking/agent
          name: skywalking-agent
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      terminationGracePeriodSeconds: 60
      volumes:
      - name: skywalking-agent
        emptyDir: {}
```

# 3、线上真实场景模拟（springboot微服务）

**1、Springboot微服务 - UI服务**

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: acme-financial-ui
  name: acme-financial-ui
spec:
  replicas: 1
  selector:
    matchLabels:
      app: acme-financial-ui
  template:
    metadata:
      labels:
        app: acme-financial-ui
    spec:
      initContainers:
        - name: init-skywalking-agent
          image: harbor-local.kubernets.cn/library/skywalking-agent:8.5.0
          command:
            - 'sh'
            - '-c'
            - 'set -ex;mkdir -p /vmskywalking/agent;cp -r /skywalking/agent/* /vmskywalking/agent;'
          volumeMounts:
            - mountPath: /vmskywalking/agent
              name: skywalking-agent
      containers:
      - env:
        - name: JAVA_OPTS
          value: "-javaagent:/opt/sw/agent/skywalking-agent.jar"
        - name: SW_AGENT_NAME
          value: "acme-financial-ui"
        - name: SW_AGENT_COLLECTOR_BACKEND_SERVICES
          value: "skywalking-oap.devops.svc.cluster.local:11800"
        image: registry.cn-shanghai.aliyuncs.com/zhdya/acme-financial-ui:v0.1
        imagePullPolicy: Always
        name: ui
        ports:
        - containerPort: 8081
          protocol: TCP
        volumeMounts:
        - mountPath: /opt/sw/agent
          name: skywalking-agent
      volumes: 
      - name: skywalking-agent
        emptyDir: {}
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: acme-financial-ui
  name: acme-financial-ui
spec:
  ports:
  - name: http
    port: 8081
    protocol: TCP
    targetPort: 8081
  selector:
    app: acme-financial-ui
  sessionAffinity: None
  type: ClusterIP
```

**2、Springboot微服务 - office服务**

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: acme-financial-office
  name: acme-financial-office
spec:
  replicas: 1
  selector:
    matchLabels:
      app: acme-financial-office
  template:
    metadata:
      labels:
        app: acme-financial-office
    spec:
      initContainers:
        - name: init-skywalking-agent
          image: harbor-local.kubernets.cn/library/skywalking-agent:8.5.0
          command:
            - 'sh'
            - '-c'
            - 'set -ex;mkdir -p /vmskywalking/agent;cp -r /skywalking/agent/* /vmskywalking/agent;'
          volumeMounts:
            - mountPath: /vmskywalking/agent
              name: skywalking-agent
      containers:
      - env:
        - name: JAVA_OPTS
          value: "-javaagent:/opt/sw/agent/skywalking-agent.jar"
        - name: SW_AGENT_NAME
          value: "acme-financial-office"
        - name: SW_AGENT_COLLECTOR_BACKEND_SERVICES
          value: "skywalking-oap.devops.svc.cluster.local:11800"
        image: registry.cn-shanghai.aliyuncs.com/zhdya/acme-financial-office:v0.1
        imagePullPolicy: Always
        name: office
        ports:
        - containerPort: 8082
          protocol: TCP
        volumeMounts:
        - mountPath: /opt/sw/agent
          name: skywalking-agent
      volumes: 
      - name: skywalking-agent
        emptyDir: {}

---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: acme-financial-office
  name: acme-financial-back-office
spec:
  ports:
  - name: http
    port: 8082
    protocol: TCP
    targetPort: 8082
  selector:
    app: acme-financial-office
  sessionAffinity: None
  type: ClusterIP
```

**3、Springboot微服务 - account服务**

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: acme-financial-account
  name: acme-financial-account
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: acme-financial-account
  template:
    metadata:
      labels:
        app: acme-financial-account
    spec:
      initContainers:
        - name: init-skywalking-agent
          image: harbor-local.kubernets.cn/library/skywalking-agent:8.5.0
          command:
            - 'sh'
            - '-c'
            - 'set -ex;mkdir -p /vmskywalking/agent;cp -r /skywalking/agent/* /vmskywalking/agent;'
          volumeMounts:
            - mountPath: /vmskywalking/agent
              name: skywalking-agent
      containers:
      - env:
        - name: JAVA_OPTS
          value: "-javaagent:/opt/sw/agent/skywalking-agent.jar"
        - name: SW_AGENT_NAME
          value: "acme-financial-account"
        - name: SW_AGENT_COLLECTOR_BACKEND_SERVICES
          value: "skywalking-oap.devops.svc.cluster.local:11800"
        image: registry.cn-shanghai.aliyuncs.com/zhdya/acme-financial-account:v0.1
        imagePullPolicy: Always
        name: account
        ports:
        - containerPort: 8083
          protocol: TCP
        volumeMounts:
        - mountPath: /opt/sw/agent
          name: skywalking-agent
      volumes: 
      - name: skywalking-agent
        emptyDir: {}
---

apiVersion: v1
kind: Service
metadata:
  labels:
    app: acme-financial-account
  name: acme-financial-account
spec:
  ports:
  - name: http
    port: 8083
    protocol: TCP
    targetPort: 8083
  selector:
    app: acme-financial-account
  sessionAffinity: None
  type: ClusterIP
```

**4、Springboot微服务 - customer服务**

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: acme-financial-customer
  name: acme-financial-customer
spec:
  replicas: 1
  selector:
    matchLabels:
      app: acme-financial-customer
  template:
    metadata:
      labels:
        app: acme-financial-customer
    spec:
      initContainers:
        - name: init-skywalking-agent
          image: harbor-local.kubernets.cn/library/skywalking-agent:8.5.0
          command:
            - 'sh'
            - '-c'
            - 'set -ex;mkdir -p /vmskywalking/agent;cp -r /skywalking/agent/* /vmskywalking/agent;'
          volumeMounts:
            - mountPath: /vmskywalking/agent
              name: skywalking-agent
      containers:
      - env:
        - name: JAVA_OPTS
          value: "-javaagent:/opt/sw/agent/skywalking-agent.jar"
        - name: SW_AGENT_NAME
          value: "acme-financial-customer"
        - name: SW_AGENT_COLLECTOR_BACKEND_SERVICES
          value: "skywalking-oap.devops.svc.cluster.local:11800"
        image: registry.cn-shanghai.aliyuncs.com/zhdya/acme-financial-customer:v0.1
        imagePullPolicy: Always
        name: customer
        ports:
        - containerPort: 8084
          protocol: TCP
        volumeMounts:
        - mountPath: /opt/sw/agent
          name: skywalking-agent
      volumes: 
      - name: skywalking-agent
        emptyDir: {}

---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: acme-financial-customer
  name: acme-financial-customer
  namespace: default
spec:
  ports:
  - name: http
    port: 8084
    protocol: TCP
    targetPort: 8084
  selector:
    app: acme-financial-customer
  sessionAffinity: None
  type: ClusterIP
```

**5、创建UI-ingress**

```yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  namespace: default
  name: acme-financial-ing
spec:
  ingressClassName: nginx
  rules:
  - host: acme.kubernets.cn
    http:
      paths:
        - pathType: Prefix
          backend:
            service:
              name: acme-financial-ui
              port:
                number: 8081
          path: /
```

**6、测试Spring微服务API**

通过Ingress访问UI服务的三个接口：/hello、/start、/readtimeout。

```bash
## 查看服务svc
$ kubectl get svc
NAME                         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
acme-financial-account       ClusterIP   10.96.54.249     <none>        8083/TCP   6m22s
acme-financial-back-office   ClusterIP   10.111.237.227   <none>        8082/TCP   6m22s
acme-financial-customer      ClusterIP   10.98.134.30     <none>        8084/TCP   6m21s
acme-financial-office        ClusterIP   10.97.42.206     <none>        8082/TCP   6m21s
acme-financial-ui            ClusterIP   10.99.246.84     <none>        8081/TCP   6m21s

## 模拟访问
$ for i in {1..5000}; do curl http://acme.kubernets.cn/hello && sleep 1; done

$ for i in {1..5000}; do curl http://acme.kubernets.cn/start && sleep 1; done

$ for i in {1..5000}; do curl http://acme.kubernets.cn/readtimeout && sleep 1; done
```

**7、查看Skywalking UI界面**

1. 吞吐量CPM，表示每分钟的调用.
2. Apdex分数:衡量服务器性能的标准
3. 响应时间百分比，包括 p99, p95, p90, p75, p50. 
4. SLA表示成功率。对于HTTP，表示响应为200的请求.

![](https://oss.zhoumx.net/img/k8s/FileSharing327.jpg)

> **拓扑图**:用指标显示服务和实例之间的关系，点击服务显示监控数据。

![](https://oss.zhoumx.net/img/k8s/FileSharing328.jpg)

> **跟踪查询**:skywalk提供的分布式代理一样的典型特性.

![](https://oss.zhoumx.net/img/k8s/FileSharing329.jpg)

> 具体接口服务报错/响应慢的主要原因

![](https://oss.zhoumx.net/img/k8s/FileSharing330.jpg)

# 4、Go应用如何接入Skywalking

[SkyWalking Go Agent 快速开始指南 | Apache SkyWalking](https://skywalking.apache.org/zh/2023-06-01-quick-start-with-skywalking-go-agent/)