k8s与UI--scope简介与部署

scope简介

scope 是 weave公司开源的用于监控，可视化，管理kubernetes集群的一个类似于dashbord的UI系统。有一下四大特点：

• 实时了解你的docker容器。
• 相关细节和深层链接。提供了容器tags，元数据，metrics等细节，也提供了cpu和内存指标。

• 集成了容器管理。可以pause，stop容器，也提供了webshell，方便对容器进行操作。

• 插件机制。这个很重要，可以根据约定，写一些自己需要的插件。官方提供的插件集中在github。

个人感觉有两个地方做的不错。第一个是scope提供了容器之间的业务拓扑，可以很方便的查看调用关系。

另外一个是scope-traffic-control插件，该插件用来控制容器的流量。
本身k8s只提供了cpu，内存和存储的限制。在官方不支持流控之前，也是一个不侵入的选择。利用的原理就是linux tc。后期我们会对该插件专门介绍。

scope部署

直接上yaml文件

apiVersion: v1
kind: List
items:
  - apiVersion: v1
    kind: Namespace
    metadata:
      name: weave
      annotations:
        cloud.weave.works/version: v1.0.0-44-gd0d2369
  - apiVersion: v1
    kind: ServiceAccount
    metadata:
      name: weave-scope
      annotations:
        cloud.weave.works/launcher-info: |-
          {
            "original-request": {
              "url": "/k8s/scope.yaml?k8s-version=1.8.0",
              "date": "Sat Feb 24 2018 09:12:44 GMT+0000 (UTC)"
            },
            "email-address": "[e-mail]"
          }
      labels:
        name: weave-scope
      namespace: weave
  - apiVersion: rbac.authorization.k8s.io/v1beta1
    kind: ClusterRole
    metadata:
      name: weave-scope
      annotations:
        cloud.weave.works/launcher-info: |-
          {
            "original-request": {
              "url": "/k8s/scope.yaml?k8s-version=1.8.0",
              "date": "Sat Feb 24 2018 09:12:44 GMT+0000 (UTC)"
            },
            "email-address": "[e-mail]"
          }
      labels:
        name: weave-scope
      namespace: weave
    rules:
      - apiGroups:
          - '*'
        resources:
          - '*'
        verbs:
          - '*'
      - nonResourceURLs:
          - '*'
        verbs:
          - '*'
  - apiVersion: rbac.authorization.k8s.io/v1beta1
    kind: ClusterRoleBinding
    metadata:
      name: weave-scope
      annotations:
        cloud.weave.works/launcher-info: |-
          {
            "original-request": {
              "url": "/k8s/scope.yaml?k8s-version=1.8.0",
              "date": "Sat Feb 24 2018 09:12:44 GMT+0000 (UTC)"
            },
            "email-address": "[e-mail]"
          }
      labels:
        name: weave-scope
      namespace: weave
    roleRef:
      kind: ClusterRole
      name: weave-scope
      apiGroup: rbac.authorization.k8s.io
    subjects:
      - kind: ServiceAccount
        name: weave-scope
        namespace: weave
  - apiVersion: apps/v1beta1
    kind: Deployment
    metadata:
      name: weave-scope-app
      annotations:
        cloud.weave.works/launcher-info: |-
          {
            "original-request": {
              "url": "/k8s/scope.yaml?k8s-version=1.8.0",
              "date": "Sat Feb 24 2018 09:12:44 GMT+0000 (UTC)"
            },
            "email-address": "[e-mail]"
          }
      labels:
        name: weave-scope-app
        app: weave-scope
        weave-cloud-component: scope
        weave-scope-component: app
      namespace: weave
    spec:
      replicas: 1
      revisionHistoryLimit: 2
      template:
        metadata:
          labels:
            name: weave-scope-app
            app: weave-scope
            weave-cloud-component: scope
            weave-scope-component: app
        spec:
          containers:
            - name: app
              args:
                - '--no-probe'
                - '--weave=false'
              env: []
              image: 'registry.xxx.com/kubernetes/scope:1.7.3'
              imagePullPolicy: IfNotPresent
              ports:
                - containerPort: 4040
                  protocol: TCP
  - apiVersion: v1
    kind: Service
    metadata:
      name: weave-scope-app
      annotations:
        cloud.weave.works/launcher-info: |-
          {
            "original-request": {
              "url": "/k8s/scope.yaml?k8s-version=1.8.0",
              "date": "Sat Feb 24 2018 09:12:44 GMT+0000 (UTC)"
            },
            "email-address": "[e-mail]"
          }
      labels:
        name: weave-scope-app
        app: weave-scope
        weave-cloud-component: scope
        weave-scope-component: app
      namespace: weave
    spec:
      type: NodePort 
      ports:
        - name: app
          port: 80
          protocol: TCP
          targetPort: 4040
          nodePort: 32404
      selector:
        name: weave-scope-app
        app: weave-scope
        weave-cloud-component: scope
        weave-scope-component: app
  - apiVersion: extensions/v1beta1
    kind: DaemonSet
    metadata:
      name: weave-scope-agent
      annotations:
        cloud.weave.works/launcher-info: |-
          {
            "original-request": {
              "url": "/k8s/scope.yaml?k8s-version=1.8.0",
              "date": "Sat Feb 24 2018 09:12:44 GMT+0000 (UTC)"
            },
            "email-address": "[e-mail]"
          }
      labels:
        name: weave-scope-agent
        app: weave-scope
        weave-cloud-component: scope
        weave-scope-component: agent
      namespace: weave
    spec:
      template:
        metadata:
          labels:
            name: weave-scope-agent
            app: weave-scope
            weave-cloud-component: scope
            weave-scope-component: agent
        spec:
          containers:
            - name: scope-agent
              args:
                - '--no-app'
                - '--probe.docker.bridge=docker0'
                - '--probe.docker=true'
                - '--probe.kubernetes=true'
                - 'weave-scope-app.weave:80'
                - '--weave=false'
              env:
                - name: KUBERNETES_HOSTNAME
                  valueFrom:
                    fieldRef:
                      apiVersion: v1
                      fieldPath: spec.nodeName
              image: 'registry.xxx.com/kubernetes/scope:1.7.3'
              imagePullPolicy: IfNotPresent
              securityContext:
                privileged: true
              volumeMounts:
                - name: docker-socket
                  mountPath: /var/run/docker.sock
                - name: scope-plugins
                  mountPath: /var/run/scope/plugins
                - name: sys-kernel-debug
                  mountPath: /sys/kernel/debug
          dnsPolicy: ClusterFirstWithHostNet
          hostNetwork: true
          hostPID: true
          serviceAccountName: weave-scope
          tolerations:
            - effect: NoSchedule
              operator: Exists
          volumes:
            - name: docker-socket
              hostPath:
                path: /var/run/docker.sock
            - name: scope-plugins
              hostPath:
                path: /var/run/scope/plugins
            - name: sys-kernel-debug
              hostPath:
                path: /sys/kernel/debug
      updateStrategy:
        type: RollingUpdate

• 将镜像源修改为自己服务器可以pull到即可。
• 由于scope没有提供登录认证的功能。所以没有通过ingress映射到外网。通过nodeport将service暴露，内网可以访问。当然可以轻松改造，整个接口采用mux实现，实现一个自己的认证中间件即可，这就是后续工作了。
• 如果你的k8s版本不是1.8.0，那么你可以获取yaml文件通过下面语句

curl https://cloud.weave.works/k8s/scope.yaml?k8s-version=1.6.7 -sL -o scope.yaml

最后上一张效果图

总结

当然如果是一个商用的k8s集群，scope远远不够。但是对于内部使用，scope是dashbord的一种很好的补充，也可以扩展，来满足自己。