如何引用k8s yaml文件中的label值

Question

我想在 k8s yaml 文件中的 VirtualService 规范部分引用标签值。我使用 ${metadata.labels[component]} 来表示下面的位置。有没有办法实现我的想法？

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: istio-ingress-version
  namespace: netops
  labels:
    component: version
spec:
  hosts:
  - "service.api.com" 
  gateways:
  - public-inbound-gateway 
  http:
  - match: 
    - uri:
        prefix: /${metadata.labels[component]}/
      headers: 
        referer:
          regex: ^https://[^\s/]*a.api.com[^\s]* 
    rewrite:
      uri: "/"
    route:
    - destination:
        host: ${metadata.labels[component]}.3da.svc.cluster.local  
  - match: 
    - uri:
        prefix: /${metadata.labels[component]}/
      headers: 
        referer:
          regex: ^https://[^\s/]*b.api.com[^\s]* 
    rewrite:
      uri: "/"
    route:
    - destination:
        host: ${metadata.labels[component]}.3db.svc.cluster.local  
  - match: 
    - uri:
        prefix: /${metadata.labels[component]}/
    rewrite:
      uri: "/"
    route:
    - destination:
        host: ${metadata.labels[component]}.3db.svc.cluster.local

Answer 1

这不是 Kubernetes 本身的功能，但是存在其他工具可以帮助您处理这种情况。

其中最主要的是Helm。它允许您创建可以在多个不同的 YAML 文件之间共享的变量，允许您共享值甚至完全参数化您的部署。

Answer 2

查看 downwardAPI 以在运行时将标签和注释等 pod 元数据注入 pods。

apiVersion: v1
kind: Pod
metadata:
  name: kubernetes-downwardapi-volume-example
  labels:
    zone: us-est-coast
    cluster: test-cluster1
    rack: rack-22
  annotations:
    build: two
    builder: john-doe
spec:
  containers:
    - name: client-container
      image: gcr.io/google_containers/busybox
      command: ["sh", "-c", "while true; do if [[ -e /etc/labels ]]; then cat /etc/labels; fi; if [[ -e /etc/annotations ]]; then cat /etc/annotations; fi; sleep 5; done"]
      volumeMounts:
        - name: podinfo
          mountPath: /etc
          readOnly: false
  volumes:
    - name: podinfo
      downwardAPI:
        items:
          - path: "labels"
            fieldRef:
              fieldPath: metadata.labels
          - path: "annotations"
            fieldRef:
              fieldPath: metadata.annotations

如何引用k8s yaml文件中的label值

How to reference the label value in k8s yaml file

yaml

kubernetes

istio

查看 downwardAPI 以在运行时将标签和注释等 pod 元数据注入 pods。