如何在Kubernetes上修补已部署的Ingress资源？

Question

我有以下Ingress资源：

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: main-ingress
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
    nginx.ingress.kubernetes.io/force-ssl-redirect: "false"
    nginx.ingress.kubernetes.io/proxy-read-timeout: "86400"
    nginx.ingress.kubernetes.io/proxy-send-timeout: "86400"

spec:
  tls:
  - secretName: the-secret
    hosts:
      - sample.domain.com
      - sample2.domain.com
      - rabbit.domain.com
      - hub.domain.com
      - grafana.domain.com

  rules:

  - host: sample.domain.com
    http:
      paths:
      - path: /
        backend:
          serviceName: fe-srvc
          servicePort: 80
      - path: /api
        backend:
          serviceName: be-srvc
          servicePort: 80

  - host: sample2.domain.com
    http:
      paths:
      - path: /
        backend:
          serviceName: fe2-srvc
          servicePort: 80
      - path: /api
        backend:
          serviceName: be-srvc
          servicePort: 80

## The Extra Services ###
  - host: rabbit.domain.com
    http:
      paths:
      - path: /
        backend:
          serviceName: rabbitmq-srvc
          servicePort: 80

我想在部署后对其进行修补。

所以我用它来尝试将be-srvc值替换为some-srvc：

kubectl patch ing/main-ingress --patch '{ "spec" : { "rules": [{"http":{"paths":[ {"- path":"/"},{"backend":{"serviceName":"other-srvc"}},{"servicePort":"80"} ] }}]}}'

我得到这个错误：

The Ingress "main-ingress" is invalid:
* spec.rules[0].http.backend.serviceName: Required value
* spec.rules[0].http.backend.servicePort: Invalid value: 0: must be between 1 and 65535, inclusive

任何见识将不胜感激！

Answer 1

您的补丁程序有很多问题；例如，"- path"代替"path"但又不正确地引用对象级别。但是，即使您纠正了错误，也无法按预期进行。让我们看看为什么。

kubectl patch是对战略合并补丁的要求。在.spec.rules和阵列打补丁时，如和，.spec.rules.http.paths在这种情况下，战略性合并补丁程序可以使用定义的补丁程序类型和对象的合并补丁程序合并键执行正确的操作。但是，对于Ingress对象，没有人愿意定义它们。这意味着任何补丁都将覆盖整个对象。它不会是一个人们希望的很好的合并。

要完成问题中提到的特定更改，您可以执行以下操作：

kubectl get ing/main-ingress -o json \ 
  | jq '(.spec.rules[].http.paths[].backend.serviceName | select(. == "be-srvc")) |= "some-srvc"' \
  | kubectl apply -f -

以上将所有出现的be-srvc服务更改为some-srvc。请记住，这里存在一个短暂的竞争条件：如果在kubectl get运行后修改了Ingress ，更改将失败并显示错误Operation cannot be fulfilled on ingresses.extensions "xx": the object has been modified；要处理这种情况，您需要实现重试逻辑。

如果上述阵列中的索引已知，则可以直接完成补丁：

kubectl patch ing/main-ingress --type=json \
  -p='[{"op": "replace", "path": "/spec/rules/0/http/paths/1/backend/serviceName", "value":"some-srvc"}]'
kubectl patch ing/main-ingress --type=json \
  -p='[{"op": "replace", "path": "/spec/rules/1/http/paths/1/backend/serviceName", "value":"some-srvc"}]'

以上两个命令将改变为后端sample.domain.com/api和sample2.domain.com/api到some-srvc。

这两个命令也可以这样组合：

kubectl patch ing/main-ingress --type=json \
  -p='[{"op": "replace", "path": "/spec/rules/0/http/paths/1/backend/serviceName", "value":"some-srvc"}, {"op": "replace", "path": "/spec/rules/1/http/paths/1/backend/serviceName", "value":"some-srvc"}]'

这具有相同的效果，并且作为额外的奖励，此处没有比赛条件。该补丁保证是原子的。