等待 http-01 传播的 Kubernetes 挑战：拨号 tcp：没有这样的主机

Question

我正在尝试创建一个 kubernetes 集群命名空间，其中包含自动生成的用于入口的 DNS，并使用Let's Encrypt TLS 证书进行保护。不幸的是，我遇到了一些麻烦，不知道在哪里寻找解决方案。

正在使用多阶段 yaml 管道将其部署到 AKS 集群中，我已经在单独的命名空间中设置了 nginx 入口控制器和证书管理器。部署成功，一切似乎都在运行，但无法访问来自入口的公开主机名。查看证书时，我看到以下内容

Name:         letsencrypt-tls-cd
Namespace:    myApp-dev
Labels:       app.kubernetes.io/instance=myApp
              app.kubernetes.io/managed-by=Helm
              app.kubernetes.io/name=cd
              app.kubernetes.io/version=9.3.0
              helm.sh/chart=cd-1.0.0
Annotations:  <none>
API Version:  cert-manager.io/v1alpha3
Kind:         Certificate
Metadata:
  Creation Timestamp:  2020-06-15T11:59:53Z
  Generation:          1
  Owner References:
    API Version:           extensions/v1beta1
    Block Owner Deletion:  true
    Controller:            true
    Kind:                  Ingress
    Name:                  myApp-cd
    UID:                   a6cbbf69-749e-4dd1-81cc-37a817051690
  Resource Version:        1218430
  Self Link:               /apis/cert-manager.io/v1alpha3/namespaces/myApp-dev/certificates/letsencrypt-tls-cd
  UID:                     46ac0acb-71bf-4dbc-a376-c024e92d68ca
Spec:
  Dns Names:
    cd-myApp-dev.dev
  Issuer Ref:
    Group:      cert-manager.io
    Kind:       Issuer
    Name:       letsencrypt-prod
  Secret Name:  letsencrypt-tls-cd
Status:
  Conditions:
    Last Transition Time:  2020-06-15T11:59:53Z
    Message:               ***Waiting for CertificateRequest "letsencrypt-tls-cd-95531636" to complete***
    Reason:                InProgress
    Status:                False
    Type:                  Ready
Events:
  Type    Reason        Age   From          Message
  ----    ------        ----  ----          -------
  Normal  GeneratedKey  57m   cert-manager  Generated a new private key
  Normal  Requested     57m   cert-manager  Created new CertificateRequest resource "letsencrypt-tls-cd-95531636"

查看证书请求：

Name:         letsencrypt-tls-cd-95531636
Namespace:    myApp-dev
Labels:       app.kubernetes.io/instance=myApp
              app.kubernetes.io/managed-by=Helm
              app.kubernetes.io/name=cd
              app.kubernetes.io/version=9.3.0
              helm.sh/chart=cd-1.0.0
Annotations:  cert-manager.io/certificate-name: letsencrypt-tls-cd
              cert-manager.io/private-key-secret-name: letsencrypt-tls-cd
API Version:  cert-manager.io/v1alpha3
Kind:         CertificateRequest
Metadata:
  Creation Timestamp:  2020-06-15T11:59:54Z
  Generation:          1
  Owner References:
    API Version:           cert-manager.io/v1alpha2
    Block Owner Deletion:  true
    Controller:            true
    Kind:                  Certificate
    Name:                  letsencrypt-tls-cd
    UID:                   46ac0acb-71bf-4dbc-a376-c024e92d68ca
  Resource Version:        1218442
  Self Link:               /apis/cert-manager.io/v1alpha3/namespaces/myApp-dev/certificaterequests/letsencrypt-tls-cd-95531636
  UID:                     2bef5e93-6722-43c0-bd2c-283d70334b1c
Spec:
  Csr:  mySecret
  Issuer Ref:
    Group:  cert-manager.io
    Kind:   Issuer
    Name:   letsencrypt-prod
Status:
  Conditions:
    Last Transition Time:  2020-06-15T11:59:54Z
    Message:               Waiting on certificate issuance from order myApp-dev/letsencrypt-tls-cd-95531636-1679437339: "pending"
    Reason:                Pending
    Status:                False
    Type:                  Ready
Events:
  Type    Reason        Age   From          Message
  ----    ------        ----  ----          -------
  Normal  OrderCreated  58m   cert-manager  Created Order resource myApp-dev/letsencrypt-tls-cd-95531636-1679437339

以及挑战：

Name:         letsencrypt-tls-cm-1259919220-2936945618-694921812
Namespace:    myApp-dev
Labels:       <none>
Annotations:  <none>
API Version:  acme.cert-manager.io/v1alpha3
Kind:         Challenge
Metadata:
  Creation Timestamp:  2020-06-15T11:59:55Z
  Finalizers:
    finalizer.acme.cert-manager.io
  Generation:  1
  Owner References:
    API Version:           acme.cert-manager.io/v1alpha2
    Block Owner Deletion:  true
    Controller:            true
    Kind:                  Order
    Name:                  letsencrypt-tls-cm-1259919220-2936945618
    UID:                   4d8eab8e-449b-494e-a751-912a77671223
  Resource Version:        1218492
  Self Link:               /apis/acme.cert-manager.io/v1alpha3/namespaces/myApp-dev/challenges/letsencrypt-tls-cm-1259919220-2936945618-694921812
  UID:                     8b355336-309a-4192-83b7-41397ebc20ac
Spec:
  Authz URL:  https://acme-v02.api.letsencrypt.org/acme/authz-v3/5253543313
  Dns Name:   cm-myApp-dev.dev
  Issuer Ref:
    Group:  cert-manager.io
    Kind:   Issuer
    Name:   letsencrypt-prod
  Key:      0USdpDsQg7_NY1FB138oj6O3AtVVKn6rkdxUSBQk4KI.qZ3FGlVmwRY6MwBNqUR5iktM1fJWdXxFWZYFOpjSUkQ
  Solver:
    http01:
      Ingress:
        Class:  nginx
        Pod Template:
          Metadata:
          Spec:
            Node Selector:
              kubernetes.io/os:  linux
  Token:                         0USdpDsQg7_NY1FB138oj6O3AtVVKn6rkdxUSBQk4KI
  Type:                          http-01
  URL:                           https://acme-v02.api.letsencrypt.org/acme/chall-v3/5253543313/1eUG0g
  Wildcard:                      false
Status:
  Presented:   true
  Processing:  true
  Reason:      Waiting for http-01 challenge propagation: failed to perform self check GET request 'http://cm-myApp-dev.dev/.well-known/acme-challenge/0USdpDsQg7_NY1FB138oj6O3AtVVKn6rkdxUSBQk4KI': Get "http://cm-myApp-dev.dev/.well-known/acme-challenge/0USdpDsQg7_NY1FB138oj6O3AtVVKn6rkdxUSBQk4KI": dial tcp: lookup cm-myApp-dev.dev on 10.0.0.10:53: no such host
  State:       pending
Events:
  Type    Reason     Age    From          Message
  ----    ------     ----   ----          -------
  Normal  Started    2m15s  cert-manager  Challenge scheduled for processing
  Normal  Presented  2m14s  cert-manager  Presented challenge using http-01 challenge mechanism

我对 kubernetes 很陌生，不知道在哪里可以修复下面的错误，非常感谢任何帮助。

Waiting for http-01 challenge propagation: failed to perform self check GET request 'http://cm-myApp-dev.dev/.well-known/acme-challenge/0USdpDsQg7_NY1FB138oj6O3AtVVKn6rkdxUSBQk4KI': Get "http://cm-myApp-dev.dev/.well-known/acme-challenge/0USdpDsQg7_NY1FB138oj6O3AtVVKn6rkdxUSBQk4KI": dial tcp: lookup cm-myApp-dev.dev on 10.0.0.10:53: no such host

查看入口控制器我收到以下错误：

    7 controller.go:1374] Error getting SSL certificate "myApp-dev/letsencrypt-tls-cd": local SSL certificate myApp-dev/letsencrypt-tls-cd was not found
W0616 06:24:29.033235       7 controller.go:1119] Error getting SSL certificate "myApp-dev/letsencrypt-tls-cm": local SSL certificate myApp-dev/letsencrypt-tls-cm was not found. Using default certificate
W0616 06:24:29.033264       7 controller.go:1374] Error getting SSL certificate "myApp-dev/letsencrypt-tls-cd": local SSL certificate myApp-dev/letsencrypt-tls-cd was not found
I0616 06:24:50.355937       7 status.go:275] updating Ingress myApp-dev/cm-acme-http-solver-9z88h status from [] to [{10.240.0.252 } {10.240.1.58 }]
W0616 06:24:50.363181       7 controller.go:1119] Error getting SSL certificate "myApp-dev/letsencrypt-tls-cm": local SSL certificate myApp-dev/letsencrypt-tls-cm was not found. Using default certificate
W0616 06:24:50.363346       7 controller.go:1374] Error getting SSL certificate "myApp-dev/letsencrypt-tls-cd": local SSL certificate myApp-dev/letsencrypt-tls-cd was not found
I0616 06:24:50.363514       7 event.go:278] Event(v1.ObjectReference{Kind:"Ingress", Namespace:"myApp-dev", Name:"cm-acme-http-solver-9z88h", UID:"1b53f4dc-1b52-4f11-9cd0-6ffe1d0d9d40", APIVersion:"networking.k8s.io/v1beta1", ResourceVersion:"1451371", FieldPath:""}): type: 'Normal' reason: 'UPDATE' Ingress myApp-dev/cm-acme-http-solver-9z88h

Answer 1

如果有人用 Google 搜索到此问题，就会知道这个问题也可能是由 Kubernetes 集群中的 DNS 缓存引起的。在这种情况下，这是一个暂时性错误，但在某些情况下速度可能很重要（例如，如果您是托管服务提供商）。

我在这里写过，但只是总结一下。

• cert-manager 会暂时发出“no such host”错误，并最终成功
• 我的 coredns ConfigMap（在kube-system命名空间中）规定了本地 DNS 解析器和 30 秒缓存
• 您可以通过以下方式解决延迟：(1) 删除缓存，以及(2) 将解析器指向 Google DNS（或其他，具体取决于您的需要）

希望这个指针对某人有帮助。