在AWS EKS中,我如何定义ingress为多个子域名URL使用一个ALB,每个子域名都有自己的证书



我有多个服务需要暴露在互联网上,但我想为它们使用一个ALB。

我使用的是最新的AWS负载均衡器控制器,我一直在阅读这里的文档(https://kubernetes-sigs.github.io/aws-load-balancer-controller/guide/ingress/annotations/#traffic-路由(,但我还没有找到关于如何实现这一点的明确解释。

设置如下:

我有service-a.example.com-和-service-b.example.com。它们在亚马逊证书管理器中都有自己的证书。

在Kubernetes中,每个都有自己的服务对象,定义如下(每个都是唯一的(:

apiVersion: v1
kind: Service
metadata:
name: svc-a-service
annotations:
alb.ingress.kubernetes.io/healthcheck-protocol: HTTP
alb.ingress.kubernetes.io/healthcheck-port: traffic-port
alb.ingress.kubernetes.io/healthy-threshold-count: '5'
alb.ingress.kubernetes.io/unhealthy-threshold-count: '2'
alb.ingress.kubernetes.io/healthcheck-path: /index.html
alb.ingress.kubernetes.io/healthcheck-interval-seconds: '30'
alb.ingress.kubernetes.io/healthcheck-timeout-seconds: '5'
alb.ingress.kubernetes.io/success-codes: '200'
alb.ingress.kubernetes.io/tags: Environment=Test,App=ServiceA
spec:
selector:
app: service-a
ports:
- port: 80
targetPort: 80
type: NodePort

每个服务都有自己的Ingress对象,定义如下(同样,每个服务都是唯一的,并且为每个服务指定了正确的证书(:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: svc-a-ingress
annotations:
kubernetes.io/ingress.class: alb
alb.ingress.kubernetes.io/group.name: services
alb.ingress.kubernetes.io/scheme: internet-facing
alb.ingress.kubernetes.io/security-groups: sg-01234567898765432
alb.ingress.kubernetes.io/ip-address-type: ipv4
alb.ingress.kubernetes.io/listen-ports: '[{"HTTP": 80}, {"HTTPS": 443}]'
alb.ingress.kubernetes.io/actions.ssl-redirect: '{"Type": "redirect", "RedirectConfig": { "Protocol": "HTTPS", "Port": "443", "StatusCode": "HTTP_301"}}'
alb.ingress.kubernetes.io/actions.response-503: >
{"type":"fixed-response","fixedResponseConfig":{"contentType":"text/plain","statusCode":"503","messageBody":"Unknown Host"}}
alb.ingress.kubernetes.io/target-type: instance
alb.ingress.kubernetes.io/load-balancer-attributes: routing.http2.enabled=true,idle_timeout.timeout_seconds=600
alb.ingress.kubernetes.io/tags: Environment=Test
alb.ingress.kubernetes.io/certificate-arn: arn:aws:acm:us-east-2:555555555555:certificate/33333333-2222-4444-AAAA-EEEEEEEEEEEE
alb.ingress.kubernetes.io/ssl-policy: ELBSecurityPolicy-2016-08
spec:
rules:
- http:
paths:
- path: /*
backend:
serviceName: ssl-redirect
servicePort: use-annotation
- path: /*
backend:
serviceName: svc-a-service
servicePort: 80
- path: /*
backend:
serviceName: response-503
servicePort: use-annotation

HTTP到HTTPS重定向按预期工作。

然而,我的两个应用程序之间没有区别,负载均衡器能够知道去往service-a.example.com和service-b.example.com的流量应该路由到两个不同的目标组。

在控制台中的HTTP:443侦听器规则中,它显示:

  1. 如果路径为/*,则转发到ServiceATargetGroup
  2. 如果路径为/*THEN返回固定503
  3. 如果路径为/*,则转发到ServiceBTargetGroup
  4. 如果路径为/*THEN返回固定503
  5. 如果请求未路由,则返回固定404

所以这里的重要问题是:入口应如何定义,以强制指定给service-a.example.com的流量到ServiceATargetGroup,以及指定给service-b.example.com流量到ServiceBTargetGroup

其次,我需要";否则未路由";以返回503而不是404。我原以为这只会在规则中出现一次(被合并(,但它是为每个入口创建的。应该如何构建我的yaml来实现这一点?

我最终明白了这一点——所以对于其他偶然发现这篇文章的人来说,以下是我解决它的方法:

诀窍在于不依赖于Ingress对象之间的合并。是的,它可以处理一定程度的合并,但作为TargetGroups的Services和作为ALB的Ingress之间并没有真正的一对一关系。因此,你必须非常谨慎,并注意每个Ingress对象中的内容。

一旦我将所有入口组合到一个对象定义中,我就可以使用以下YAML:使其完全按照我的意愿工作

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: svc-ingress
annotations:
kubernetes.io/ingress.class: alb
alb.ingress.kubernetes.io/group.name: services
alb.ingress.kubernetes.io/scheme: internet-facing
alb.ingress.kubernetes.io/security-groups: sg-01234567898765432
alb.ingress.kubernetes.io/ip-address-type: ipv4
alb.ingress.kubernetes.io/listen-ports: '[{"HTTP": 80}, {"HTTPS": 443}]'
alb.ingress.kubernetes.io/actions.ssl-redirect: '{"Type": "redirect", "RedirectConfig": { "Protocol": "HTTPS", "Port": "443", "StatusCode": "HTTP_301"}}'
alb.ingress.kubernetes.io/actions.response-503: >
{"type":"fixed-response","fixedResponseConfig":{"contentType":"text/plain","statusCode":"503","messageBody":"Unknown Host"}}
alb.ingress.kubernetes.io/actions.svc-a-host: >
{"type":"forward","forwardConfig":{"targetGroups":[{"serviceName":"svc-a-service","servicePort":80,"weight":100}]}}
alb.ingress.kubernetes.io/conditions.svc-a-host: >
[{"field":"host-header","hostHeaderConfig":{"values":["svc-a.example.com"]}}]
alb.ingress.kubernetes.io/actions.svc-b-host: >
{"type":"forward","forwardConfig":{"targetGroups":[{"serviceName":"svc-b-service","servicePort":80,"weight":100}]}}
alb.ingress.kubernetes.io/conditions.svc-b-host: >
[{"field":"host-header","hostHeaderConfig":{"values":["svc-b.example.com"]}}]
alb.ingress.kubernetes.io/target-type: instance
alb.ingress.kubernetes.io/load-balancer-attributes: routing.http2.enabled=true,idle_timeout.timeout_seconds=600
alb.ingress.kubernetes.io/tags: Environment=Test
alb.ingress.kubernetes.io/certificate-arn: arn:aws:acm:us-east-2:555555555555:certificate/33333333-2222-4444-AAAA-EEEEEEEEEEEE,arn:aws:acm:us-east-2:555555555555:certificate/44444444-3333-5555-BBBB-FFFFFFFFFFFF
alb.ingress.kubernetes.io/ssl-policy: ELBSecurityPolicy-2016-08
spec:
backend:
serviceName: response-503
servicePort: use-annotation
rules:
- http:
paths:
- backend:
serviceName: ssl-redirect
servicePort: use-annotation
- backend:
serviceName: svc-a-host
servicePort: use-annotation
- backend:
serviceName: svc-b-host
servicePort: use-annotation

默认操作:

通过在spec:下直接指定serviceName和servicePort进行设置

spec:
backend:
serviceName: response-503
servicePort: use-annotation

路由:

因为我使用的是子域,路径对我来说不起作用,所以我只是省略了路径,而是依赖主机名作为条件。

metadata:
alb.ingress.kubernetes.io/actions.svc-a-host: >
{"type":"forward","forwardConfig":{"targetGroups":[{"serviceName":"svc-a-service","servicePort":80,"weight":100}]}}
alb.ingress.kubernetes.io/conditions.svc-a-host: >
[{"field":"host-header","hostHeaderConfig":{"values":["svc-a.example.com"]}}]

最终结果:

ALB规则的配置正是我想要的:

  • 默认操作是503固定响应
  • 所有http流量都重定向到https
  • 流量基于主机标头定向到TargetGroups
AWS EKS现在有了IngressGroups的概念,因此多个入口可以共享一个入口控制器。请参阅Amazon EKS 上的应用程序负载平衡
To share an application load balancer across multiple ingress resources using IngressGroups
To join an Ingress to an Ingress group, add the following annotation to a Kubernetes Ingress resource specification.
alb.ingress.kubernetes.io/group.name: <my-group>
The group name must be:
63 characters or less in length.
Consist of lower case alphanumeric characters, -, and ., and must start and end with an alphanumeric character.
The controller will automatically merge ingress rules for all Ingresses in the same Ingress group and support them with a single ALB. Most annotations defined on an Ingress only apply to the paths defined by that Ingress. By default, Ingress resources don't belong to any Ingress group.

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