摘要：簡介是公司開源的用于監控，可視化，管理集群的一個類似于的系統。另外一個是插件，該插件用來控制容器的流量。在官方不支持流控之前，也是一個不侵入的選擇。由于沒有提供登錄認證的功能。通過將暴露，內網可以訪問。

scope 是 weave公司開源的用于監控，可視化，管理kubernetes集群的一個類似于dashbord的UI系統。有一下四大特點：

實時了解你的docker容器。

相關細節和深層鏈接。提供了容器tags，元數據，metrics等細節，也提供了cpu和內存指標。

集成了容器管理。可以pause，stop容器，也提供了webshell，方便對容器進行操作。

插件機制。這個很重要，可以根據約定，寫一些自己需要的插件。官方提供的插件集中在github。

個人感覺有兩個地方做的不錯。第一個是scope提供了容器之間的業務拓撲，可以很方便的查看調用關系。

另外一個是scope-traffic-control插件，該插件用來控制容器的流量。
本身k8s只提供了cpu，內存和存儲的限制。在官方不支持流控之前，也是一個不侵入的選擇。利用的原理就是linux tc。后期我們會對該插件專門介紹。

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": "support@weave.works"
          }
      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": "support@weave.works"
          }
      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": "support@weave.works"
          }
      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": "support@weave.works"
          }
      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": "support@weave.works"
          }
      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": "support@weave.works"
          }
      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

將鏡像源修改為自己服務器可以pull到即可。

由于scope沒有提供登錄認證的功能。所以沒有通過ingress映射到外網。通過nodeport將service暴露，內網可以訪問。當然可以輕松改造，整個接口采用mux實現，實現一個自己的認證中間件即可，這就是后續工作了。

如果你的k8s版本不是1.8.0，那么你可以獲取yaml文件通過下面語句

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

最后上一張效果圖

當然如果是一個商用的k8s集群，scope遠遠不夠。但是對于內部使用，scope是dashbord的一種很好的補充，也可以擴展，來滿足自己。