Traefik IngressRoute规则解析报错：非法字符U+005C求助

问题现象 #

配置Traefik Dashboard的IngressRoute和BasicAuth中间件后，Traefik Pod抛出规则解析错误：

time="2022-11-05T11:45:52Z" level=error msg="error while parsing rule Host(\`traefik.domain.com\`) && (PathPrefix(\`/api\`) || PathPrefix(\`/dashboard\`)): 1:6: illegal character U+005C '\' (and 2 more errors)" entryPointName=websecure routerName=traefik-traefik-dashboard-1cd33424d5fb33e10e2e@kubernetescrd
time="2022-11-05T11:45:52Z" level=error msg="invalid rule Host(\`traefik.domain.com\`) && (PathPrefix(\`/api\`) || PathPrefix(\`/dashboard\`)), error: 1:6: illegal character U+005C '\' (and 2 more errors)" routerName=traefik-traefik-dashboard-1cd33424d5fb33e10e2e@kubernetescrd entryPointName=websecure

当前使用的YAML配置如下：

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: traefik-dashboard
  namespace: traefik
spec:
  entryPoints:
    - websecure
  routes:
    - kind: Rule
      match: Host(\`traefik.domain.com\`) && (PathPrefix(\`/api\`) || PathPrefix(\`/dashboard\`))
      services:
        - name: api@internal
          kind: TraefikService
      middlewares:
        - name: traefik-dashboard-auth # Referencing the BasicAuth middleware
          namespace: traefik
  tls:
    secretName: domain-com-cert-secret
---
apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: traefik-dashboard-auth
  namespace: traefik
spec:
  basicAuth:
    secret: traefik-dashboard-auth-secret

问题原因 #

错误根源是YAML配置中match字段里的转义符\完全多余，Traefik规则语法不需要对反引号做转义处理，YAML解析时会将\识别为非法字符。

解决方法 #

修正match字段的规则写法，两种可行方式任选其一：

方式一：直接移除转义符 #

match: Host(`traefik.domain.com`) && (PathPrefix(`/api`) || PathPrefix(`/dashboard`))

方式二：用单引号包裹整个规则（避免YAML解析歧义，更稳妥） #

match: 'Host(`traefik.domain.com`) && (PathPrefix(`/api`) || PathPrefix(`/dashboard`))'

修正后的完整IngressRoute配置如下：

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: traefik-dashboard
  namespace: traefik
spec:
  entryPoints:
    - websecure
  routes:
    - kind: Rule
      match: 'Host(`traefik.domain.com`) && (PathPrefix(`/api`) || PathPrefix(`/dashboard`))'
      services:
        - name: api@internal
          kind: TraefikService
      middlewares:
        - name: traefik-dashboard-auth
          namespace: traefik
  tls:
    secretName: domain-com-cert-secret

应用修正后的配置即可解决规则解析错误。

内容的提问来源于stack exchange，提问作者Ross