如何在Host或Path级别配置Kubernetes的HAProxy Ingress控制器？

当然可以，HAProxy Ingress完全支持在Host或Path级别做精细化配置调整，不用局限于全局统一设置。下面分两种场景说明具体实现方式：

一、Host级别配置调整 #

方式1：为单个Host创建独立Ingress #

如果不同Host的配置差异较大，最清晰的方式是为每个Host单独创建Ingress资源，各自配置专属的注解：

# 针对myhost1.org的Ingress，使用长超时配置
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: gn-ingress-myhost1
  namespace: gn
  annotations:
    kubernetes.io/ingress.class: haproxy
    haproxy.org/backend-config-snippet: |
      timeout server 600s
      timeout client 600s
      timeout http-request 60s
spec:
  rules:
    - host: "myhost1.org"
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: myhost
                port:
                  number: 80

# 针对myhost2.org的Ingress，使用短超时配置
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: gn-ingress-myhost2
  namespace: gn
  annotations:
    kubernetes.io/ingress.class: haproxy
    haproxy.org/backend-config-snippet: |
      timeout server 300s
      timeout client 300s
      timeout http-request 30s
spec:
  rules:
    - host: "myhost2.org"
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: myhost2
                port:
                  number: 80

方式2：同一Ingress中区分Host配置 #

如果想在同一个Ingress里管理多个Host，可以通过haproxy.org/route-config-snippet注解，结合ACL匹配特定Host来插入差异化配置：

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: gn-ingress-multi
  namespace: gn
  annotations:
    kubernetes.io/ingress.class: haproxy
    haproxy.org/route-config-snippet: |
      # 匹配myhost1.org并设置长超时
      acl host_myhost1 hdr(host) -i myhost1.org
      timeout server 600s if host_myhost1
      timeout client 600s if host_myhost1
      
      # 匹配myhost2.org并设置短超时
      acl host_myhost2 hdr(host) -i myhost2.org
      timeout server 300s if host_myhost2
      timeout client 300s if host_myhost2
spec:
  rules:
    - host: "myhost1.org"
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: myhost
                port:
                  number: 80
    - host: "myhost2.org"
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: myhost2
                port:
                  number: 80

二、Path级别配置调整 #

方式1：通过ACL匹配Path设置差异化配置 #

如果同一个Host下不同Path需要不同配置，可以用ACL匹配Path，结合haproxy.org/route-config-snippet注解实现：

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: gn-ingress-path
  namespace: gn
  annotations:
    kubernetes.io/ingress.class: haproxy
    # 默认全局backend配置
    haproxy.org/backend-config-snippet: |
      timeout server 600s
      timeout client 600s
    # 针对/api路径设置特殊超时
    haproxy.org/route-config-snippet: |
      acl path_api path_beg /api
      timeout server 1200s if path_api
      timeout client 1200s if path_api
spec:
  rules:
    - host: "myhost1.org"
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: myhost
                port:
                  number: 80
          - path: /api
            pathType: Prefix
            backend:
              service:
                name: myhost-api
                port:
                  number: 80

方式2：为Path绑定的Service添加专属注解 #

如果不同Path对应不同的Service，直接给目标Service添加HAProxy注解，就能实现该Path对应的配置隔离：

# 为myhost-api Service配置专属超时
apiVersion: v1
kind: Service
metadata:
  name: myhost-api
  namespace: gn
  annotations:
    haproxy.org/backend-config-snippet: |
      timeout server 1200s
      timeout client 1200s
spec:
  selector:
    app: myhost-api
  ports:
    - port: 80
      targetPort: 8080

对应的Ingress正常配置Path即可：

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: gn-ingress-path-service
  namespace: gn
  annotations:
    kubernetes.io/ingress.class: haproxy
spec:
  rules:
    - host: "myhost1.org"
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: myhost
                port:
                  number: 80
          - path: /api
            pathType: Prefix
            backend:
              service:
                name: myhost-api
                port:
                  number: 80

内容的提问来源于stack exchange，提问作者dimus