配置Ingress支持HTTPS访问(二):使用cert-manager申请证书

一.系统环境

服务器版本 docker软件版本 Kubernetes(k8s)集群版本 kube-bench版本 CPU架构
Ubuntu 18.04.5 LTS Docker version 20.10.14 v1.22.2 0.6.7 x86_64

Kubernetes集群架构:k8scludes1作为master节点,k8scludes2,k8scludes3作为worker节点。

服务器 操作系统版本 CPU架构 进程 功能描述
k8scludes1/192.168.110.128 Ubuntu 18.04.5 LTS x86_64 docker,kube-apiserver,etcd,kube-scheduler,kube-controller-manager,kubelet,kube-proxy,coredns,calico k8s master节点
k8scludes2/192.168.110.129 Ubuntu 18.04.5 LTS x86_64 docker,kubelet,kube-proxy,calico k8s worker节点
k8scludes3/192.168.110.130 Ubuntu 18.04.5 LTS x86_64 docker,kubelet,kube-proxy,calico k8s worker节点

二.前言

在现代的应用程序开发中,使用HTTPS来保护数据传输的安全性变得越来越重要。而在Kubernetes集群中配置Ingress支持HTTPS访问,可以为我们的应用程序提供更高的安全性。

本文将介绍如何在Kubernetes集群中配置Ingress支持HTTPS访问,使用Let's Encrypt和cert-manager工具来自动颁发和更新权威证书。

注意 :上一篇博客《 Kubernetes集群中配置Ingress支持HTTPS访问(一):cfssl 》里,使用cfssl工具生成了证书,实现了https访问,但是那个证书是我们自定义的,不是权威机构颁发的证书,在浏览器里https访问还是有警告,此次使用cert-manager向Let’s Encrypt机构申请的证书,是权威证书,在浏览器里https访问是不会有警告的。

在Kubernetes集群中配置Ingress支持HTTPS访问的 前提 是已经有一套可以正常运行的Kubernetes集群,关于Kubernetes(k8s)集群的安装部署,可以查看博客《Ubuntu 安装部署Kubernetes(k8s)集群》 https://www.cnblogs.com/renshengdezheli/p/17632858.html。

三.Let's Encrypt和cert-manager简介

Let’s Encrypt 是一家免费、开放、自动化的证书颁发机构(CA),它提供了免费的SSL/TLS证书。Let's Encrypt的证书由ACME协议自动颁发和更新。letsencrypt官网为: https://letsencrypt.org/zh-cn/,Let's Encrypt 的运作方式可以查看文档: https://letsencrypt.org/zh-cn/how-it-works/。

cert-manager是一个用于管理证书生命周期的工具,它可以自动化证书的颁发和更新。它与Kubernetes紧密集成,可以轻松地在集群中部署和配置。cert-manager官网为: https://cert-manager.io/。

Let’s Encrypt 可以免费提供证书,不过证书只有90天有效期,过期之后需要重新申请,使用cert-manager工具可以自动向Let’s Encrypt机构申请证书和续约证书,两者结合使用事半功倍。

四.部署cert-manager

4.1 安装cert-manager

在博客《 Kubernetes集群中配置Ingress支持HTTPS访问(一):cfssl 》里详细介绍了 配置ingress对外发布服务 的步骤,本文不再赘述。

cert-manager安装文档为: https://cert-manager.io/docs/installation/。

安装cert-manager之后,会建立CRD资源类型(自定义资源类型),Kubernetes 1.7之后,提供了CRD(CustomResourceDefinitions)自定义资源的二次开发能力来扩展kubernetes API,通过此扩展可以向kubernetes API中增加新的资源类型,会比修改kubernetes apiserver的源代码或创建自定义的apiserver来的更加的简洁和容易。

查看crd资源。

root@k8scludes1:~# kubectl get crd -o wide
NAME                                                  CREATED AT
bgpconfigurations.crd.projectcalico.org               2022-04-16T18:41:13Z
bgppeers.crd.projectcalico.org                        2022-04-16T18:41:13Z
blockaffinities.crd.projectcalico.org                 2022-04-16T18:41:13Z
caliconodestatuses.crd.projectcalico.org              2022-04-16T18:41:13Z
clusterinformations.crd.projectcalico.org             2022-04-16T18:41:13Z
felixconfigurations.crd.projectcalico.org             2022-04-16T18:41:13Z
globalnetworkpolicies.crd.projectcalico.org           2022-04-16T18:41:13Z
globalnetworksets.crd.projectcalico.org               2022-04-16T18:41:13Z
hostendpoints.crd.projectcalico.org                   2022-04-16T18:41:13Z
ipamblocks.crd.projectcalico.org                      2022-04-16T18:41:13Z
ipamconfigs.crd.projectcalico.org                     2022-04-16T18:41:13Z
ipamhandles.crd.projectcalico.org                     2022-04-16T18:41:13Z
ippools.crd.projectcalico.org                         2022-04-16T18:41:13Z
ipreservations.crd.projectcalico.org                  2022-04-16T18:41:13Z
kubecontrollersconfigurations.crd.projectcalico.org   2022-04-16T18:41:13Z
networkpolicies.crd.projectcalico.org                 2022-04-16T18:41:13Z
networksets.crd.projectcalico.org                     2022-04-16T18:41:13Z

创建cert-manager目录存放文件。

root@k8scludes1:~# mkdir cert-manager

root@k8scludes1:~# cd cert-manager/

下载cert-manager的安装yaml文件。

root@k8scludes1:~# wget https://GitHub.com/cert-manager/cert-manager/releases/download/v1.8.0/cert-manager.yaml

root@k8scludes1:~/cert-manager# ls
cert-manager.yaml

查看 cert-manager.yaml 所需的镜像。

root@k8scludes1:~/cert-manager# grep image cert-manager.yaml 
          image: "quay.io/jetstack/cert-manager-cainjector:v1.8.0"
          imagePullPolICY: IfNotPresent
          image: "quay.io/jetstack/cert-manager-controller:v1.8.0"
          imagePullPolicy: IfNotPresent
          image: "quay.io/jetstack/cert-manager-webhook:v1.8.0"
          imagePullPolicy: IfNotPresent

在k8s的worker节点提前下载 cert-manager.yaml 所需的镜像。

root@k8scludes2:~# docker pull quay.io/jetstack/cert-manager-cainjector:v1.8.0
root@k8scludes2:~# docker pull quay.io/jetstack/cert-manager-controller:v1.8.0
root@k8scludes2:~# docker pull quay.io/jetstack/cert-manager-webhook:v1.8.0

root@k8scludes3:~# docker pull quay.io/jetstack/cert-manager-cainjector:v1.8.0
root@k8scludes3:~# docker pull quay.io/jetstack/cert-manager-controller:v1.8.0
root@k8scludes3:~# docker pull quay.io/jetstack/cert-manager-webhook:v1.8.0

看下载好的镜像。

root@k8scludes2:~/cert-manager# docker images | grep cert-manager
quay.io/jetstack/cert-manager-webhook                             v1.8.0    5efca4d28ca6   2 weeks ago     45.4MB
quay.io/jetstack/cert-manager-cainjector                          v1.8.0    7c3e4d23dcd7   2 weeks ago     38.6MB
quay.io/jetstack/cert-manager-controller                          v1.8.0    2b8eb1ab5ff9   2 weeks ago     57.4MB

root@k8scludes3:~/cert-manager# docker images | grep cert-manager
quay.io/jetstack/cert-manager-webhook                             v1.8.0    5efca4d28ca6   2 weeks ago     45.4MB
quay.io/jetstack/cert-manager-cainjector                          v1.8.0    7c3e4d23dcd7   2 weeks ago     38.6MB
quay.io/jetstack/cert-manager-controller                          v1.8.0    2b8eb1ab5ff9   2 weeks ago     57.4MB

安装cert-manager。

root@k8scludes1:~/cert-manager# ls
cert-manager.yaml

root@k8scludes1:~/cert-manager# kubectl apply -f cert-manager.yaml 
namespace/cert-manager created
customresourcedefinition.apiextensions.k8s.io/certificaterequests.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/certificates.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/challenges.acme.cert-manager.io created
......
deployment.apps/cert-manager-webhook created
mutatingwebhookconfiguration.admissionregistration.k8s.io/cert-manager-webhook created
validatingwebhookconfiguration.admissionregistration.k8s.io/cert-manager-webhook created

查看cert-manager命名空间里的所有资源。

root@k8scludes1:~/cert-manager# kubectl get all -n cert-manager -o wide
NAME                                           READY   STATUS    RESTARTS   AGE   IP               NODE         NOMINATED NODE   READINESS GATES
pod/cert-manager-b4d6fd99b-mndtp               1/1     Running   0          61s   10.244.1.96      k8scludes3   <none>           <none>
pod/cert-manager-cainjector-74bfccdfdf-l6kh9   1/1     Running   0          61s   10.244.218.162   k8scludes2   <none>           <none>
......
replicaset.apps/cert-manager-webhook-65b766b5f8      1         1         1       61s   cert-manager   quay.io/jetstack/cert-manager-webhook:v1.8.0      app.kubernetes.io/comPONEnt=webhook,app.kubernetes.io/instance=cert-manager,app.kubernetes.io/name=webhook,pod-tEMPlate-hash=65b766b5f8

可以看到crd是全局生效的,不受命名空间限制。

root@k8scludes1:~/cert-manager# kubectl get crd -o wide -n cert-manager
NAME                                                  CREATED AT
bgpconfigurations.crd.projectcalico.org               2022-04-16T18:41:13Z
bgppeers.crd.projectcalico.org                        2022-04-16T18:41:13Z
blockaffinities.crd.projectcalico.org                 2022-04-16T18:41:13Z
caliconodestatuses.crd.projectcalico.org              2022-04-16T18:41:13Z
certificaterequests.cert-manager.io                   2022-04-24T17:07:46Z
certificates.cert-manager.io                          2022-04-24T17:07:46Z
challenges.acme.cert-manager.io                       2022-04-24T17:07:46Z
clusterinformations.crd.projectcalico.org             2022-04-16T18:41:13Z
clusterissuers.cert-manager.io                        2022-04-24T17:07:46Z
felixconfigurations.crd.projectcalico.org             2022-04-16T18:41:13Z
globalnetworkpolicies.crd.projectcalico.org           2022-04-16T18:41:13Z
globalnetworksets.crd.projectcalico.org               2022-04-16T18:41:13Z
hostendpoints.crd.projectcalico.org                   2022-04-16T18:41:13Z
ipamblocks.crd.projectcalico.org                      2022-04-16T18:41:13Z
ipamconfigs.crd.projectcalico.org                     2022-04-16T18:41:13Z
ipamhandles.crd.projectcalico.org                     2022-04-16T18:41:13Z
ippools.crd.projectcalico.org                         2022-04-16T18:41:13Z
ipreservations.crd.projectcalico.org                  2022-04-16T18:41:13Z
issuers.cert-manager.io                               2022-04-24T17:07:46Z
kubecontrollersconfigurations.crd.projectcalico.org   2022-04-16T18:41:13Z
networkpolicies.crd.projectcalico.org                 2022-04-16T18:41:13Z
networksets.crd.projectcalico.org                     2022-04-16T18:41:13Z
orders.acme.cert-manager.io                           2022-04-24T17:07:46Z

查看和cert-manager相关的crd资源。

root@k8scludes1:~/cert-manager# kubectl get crd | grep cert
certificaterequests.cert-manager.io                   2022-04-24T17:07:46Z
certificates.cert-manager.io                          2022-04-24T17:07:46Z
challenges.acme.cert-manager.io                       2022-04-24T17:07:46Z
clusterissuers.cert-manager.io                        2022-04-24T17:07:46Z
issuers.cert-manager.io                               2022-04-24T17:07:46Z
orders.acme.cert-manager.io                           2022-04-24T17:07:46Z

4.2 创建clusterissuer

cert-manager会创建clusterissuer自定义资源,clusterissuer会向letsencrypt机构申请证书和续约证书。

用户向clusterissuer提出申请证书请求,clusterissuer向letsencrypt机构申请证书,letsencrypt机构进行审核,假如申请的域名为www.nginxx.com,letsencrypt,机构会审核www.nginxx.com这个站点是不是你的?审核的方式有:http01和dns01。

  • 使用http01的审核方式:letsencrypt机构会登录到www.nginxx.com,看看能不能访问成功,访问成功就证明是你的网站,我们现在测试环境为内网环境,letsencrypt访问不了;
  • 使用dns01的审核方式:如果www.nginxx.com是你的站点,你肯定有dns服务器的操控权,在DNS服务器上生成一个api token,letsencrypt会尝试使用这个api token往DNS服务器写入内容,如果能写入成功,则说明www.nginxx.com站点是你的,就会审核通过。本文使用dns01的方式。

现在还没有clusterissuer资源,clusterissuer是全局生效的,不受命名空间限制。

root@k8scludes1:~/cert-manager# kubectl get clusterissuer
No resources found

root@k8scludes1:~/cert-manager# kubectl get clusterissuer -n cert-manager
No resources found

创建Issuer和ClusterIssuer可以去官网找例子: https://cert-manager.io/docs/configuration/acme/dns01/。

letsencrypt审核域名的方式我们使用DNS01的方式,letsencrypt支持的DNS服务器有限,本次使用Cloudflare DNS服务器。

root@k8scludes1:~/cert-manager# cat clusterissuer.yaml 
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  #ClusterIssuer的名字
  name: letsencrypt-dns01
spec:
  acme:
    privateKeySecretRef:
      name: letsencrypt-dns01
      #ClusterIssuer去https://acme-v02.api.letsencrypt.org/directory申请证书
    server: https://acme-v02.api.letsencrypt.org/directory
    solvers:
    - dns01:
        cloudflare:
          email: [email protected] 
          apiTokenSecretRef:
            key: api-token
            name: cloudflare-api-token-secret            

cert-manager配置cloudflare DNS的yaml文件可以查看官网示例: https://cert-manager.io/docs/configuration/acme/dns01/cloudflare/。

要使用Cloudflare DNS服务器,需要先注册一个Cloudflare账号,Cloudflare网址为: https://dash.cloudflare.com/login。

注册成功之后登录Cloudflare。

添加站点,但是域名没有注册,现在先去阿里云申请一个域名。

4.3 申请域名

登录阿里云,工作台-->点击域名。

点击注册域名。

输入域名--->查域名,我申请的域名为rengshengdezheli。

选择一个便宜的域名,加入清单。

点击域名清单。

结算一下。

经过个人信息审核之后,域名申请下来了,我的域名为rengshengdezheli.xyz。

在域名列表查看域名信息。

此时域名申请成功了。

4.4 Cloudflare添加站点

使用新申请到的域名,到Cloudflare添加站点。

选择免费的计划,点击继续。

点击继续。

点击确定。

4.5 修改阿里云的名称服务器为cloudflare名称服务器

按照要求要把阿里云的名称服务器更改为cloudflare名称服务器。

去到阿里云网站,找到域名,域名列表,点击修改DNS。

点击修改DNS服务器。

把DNS服务器修改为cloudflare的DNS服务器,最后点击确定。

现在就修改好了。

返回cloudflare网站,检查名称服务器。

配置好之后会出现如下界面。

现在域名rengshengdezheli.xyz的DNS服务器就是cloudflare服务器了。

4.6 获取API Tokens

根据cert-manager官网的指引: https://cert-manager.io/docs/configuration/acme/dns01/cloudflare/,我们获取API Tokens。

回到Cloudflare网站,点击获取您的API令牌

点击创建令牌。

创建自定义令牌,点击开始使用。

填写API令牌的名称,权限和区域资源按照cert-manager的要求设置,点击继续以显示摘要。

点击创建令牌。

此时API令牌就创建好了。

测试我们创建的令牌是否正常。"success":true表示我们创建的令牌正常了。

root@k8scludes1:~/cert-manager# curl -X GET "https://api.cloudflare.com/client/v4/user/tokens/verify" \
>      -H "Authorization: Bearer LKA4oW_7lHqgD66UgbTK5cMYq_4JUQ7kirCGCRj4" \
>      -H "Content-Type:application/json"
{"result":{"id":"8ee3954262ba4d0aeaa90c6fbe94af69","status":"active"},"success":true,"errors":[],"messages":[{"code":10000,"message":"This API Token is valid and active","type":null}]}root@k8scludes1:~/cert-manager# 

letsencrypt通过我们创建的API令牌就可以往我们的cloudflare DNS服务器里写入内容,如果成功写入内容,则证明站点rengshengdezheli.xyz是我们的,则审核通过。

4.7 创建secret存储API token

现在需要把API令牌告诉letsencrypt,通过clusterissuer告诉letsencrypt我们的API令牌。

因为创建clusterissuer需要存着API token的secret,所以现在创建secret。

查看 cert-manager命名空间的secret。

root@k8scludes1:~/cert-manager# kubectl get secrets -n cert-manager
NAME                                  TYPE                                  DATA   AGE
cert-manager-cainjector-token-ltxpd   kubernetes.io/service-account-token   3      19h
cert-manager-token-k5s55              kubernetes.io/service-account-token   3      19h
cert-manager-webhook-ca               Opaque                                3      19h
cert-manager-webhook-token-x94pp      kubernetes.io/service-account-token   3      19h
default-token-wl2sx                   kubernetes.io/service-account-token   3      19h

创建一个secret存储API令牌,secret的创建方法,官网也有例子。

apiVersion: v1
kind: Secret
metadata:
  name: cloudflare-api-token-secret
type: Opaque
stringData:
  api-token: <API Token>

本次使用命令行的方式创建secret,--from-literal指定键值对: api-token是键,LKA4oW_7lHqgD66UgbTK5cMYq_4JUQ7kirCGCRj4 就是我们创建的API令牌(API token )。

root@k8scludes1:~/cert-manager# kubectl create secret generic cloudflare-api-token-secret --from-literal=api-token=LKA4oW_7lHqgD66UgbTK5cMYq_4JUQ7kirCGCRj4 -n cert-manager 
secret/cloudflare-api-token-secret created

查看创建的secrets。

root@k8scludes1:~/cert-manager# kubectl get secrets -n cert-manager 
NAME                                  TYPE                                  DATA   AGE
cert-manager-cainjector-token-ltxpd   kubernetes.io/service-account-token   3      19h
cert-manager-token-k5s55              kubernetes.io/service-account-token   3      19h
cert-manager-webhook-ca               Opaque                                3      19h
cert-manager-webhook-token-x94pp      kubernetes.io/service-account-token   3      19h
cloudflare-api-token-secret           Opaque                                1      116s
default-token-wl2sx                   kubernetes.io/service-account-token   3      19h

4.8 配置clusterissuer

存储API token的secret创建好了,就可以创建clusterissuer了。

root@k8scludes1:~/cert-manager# vim clusterissuer.yaml 

root@k8scludes1:~/cert-manager# cat clusterissuer.yaml 
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  #ClusterIssuer名字
  name: letsencrypt-dns01
spec:
  acme:
    privateKeySecretRef:
      name: letsencrypt-dns01
      #ClusterIssuer去https://acme-v02.api.letsencrypt.org/directory申请证书
    server: https://acme-v02.api.letsencrypt.org/directory
    solvers:
    - dns01:
        cloudflare:
          email: 5386225891@QQ.com
          #指定存储着API token的secret,secret的名字为cloudflare-api-token-secret,secret的key为api-token
          apiTokenSecretRef:
            key: api-token
            name: cloudflare-api-token-secret

下面创建clusterissuer。

root@k8scludes1:~/cert-manager# kubectl apply -f clusterissuer.yaml 
clusterissuer.cert-manager.io/letsencrypt-dns01 created

clusterissuer创建成功。

root@k8scludes1:~/cert-manager# kubectl get clusterissuers.cert-manager.io 
NAME                READY   AGE
letsencrypt-dns01   True    29s

root@k8scludes1:~/cert-manager# kubectl get clusterissuers.cert-manager.io -o wide
NAME                READY   STATUS                                                 AGE
letsencrypt-dns01   True    The ACME account was registered with the ACME server   33s

clusterissuers创建好之后,下面开始申请证书。

五.申请证书

查看现在是否有证书,现在没有证书。

root@k8scludes1:~/cert-manager# kubectl get certificate -o wide
No resources found in tls-ingress namespace.

编写申请证书的yaml文件。

root@k8scludes1:~/cert-manager# vim certificate.yaml 

root@k8scludes1:~/cert-manager# cat certificate.yaml 
apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  #cert-zheli-com是申请的证书名字
  name: cert-zheli-com
spec:
  dnsNames:
  #www.rengshengdezheli.xyz表示申请的证书只给www.rengshengdezheli.xyz用
  - www.rengshengdezheli.xyz
  issuerRef:
    kind: ClusterIssuer
    #name: letsencrypt-dns01表示使用哪个ClusterIssuer申请证书
    name: letsencrypt-dns01 
  #secretName: cert-zheli-com-tls表示申请到的证书放在哪个secret里面
  secretName: cert-zheli-com-tls 

现在申请证书。

root@k8scludes1:~/cert-manager# kubectl apply -f certificate.yaml 
certificate.cert-manager.io/cert-zheli-com created

查看证书,有证书但是READY状态为False。

root@k8scludes1:~/cert-manager# kubectl get certificate -o wide
NAME             READY   SECRET               ISSUER              STATUS                                         AGE
cert-zheli-com   False   cert-zheli-com-tls   letsencrypt-dns01   Issuing certificate as Secret does not exist   26s

查看secret。

root@k8scludes1:~/cert-manager# kubectl get secrets -o wide
NAME                   TYPE                                  DATA   AGE
cert-zheli-com-btt2t   Opaque                                1      2m16s
default-token-mxb4r    kubernetes.io/service-account-token   3      7d8h
test-tls-secret        kubernetes.io/tls                     2      3d8h

查看证书请求。

root@k8scludes1:~/cert-manager# kubectl get certificaterequests.cert-manager.io -o wide
NAME                   APPROVED   DENIED   READY   ISSUER              REQUESTOR                                         STATUS                                         AGE
cert-zheli-com-cbkt2   True                True    letsencrypt-dns01   system:serviceaccount:cert-manager:cert-manager   Certificate fetched from issuer successfully   3m54s

查看challenges,challenges用来验证证书请求是否成功,当证书申请成功之后,challenges会消失,certificaterequests的READY状态变为True。

root@k8scludes1:~/cert-manager# kubectl get challenges.acme.cert-manager.io -o wide
No resources found in tls-ingress namespace.

现在cert-zheli-com证书申请成功,READY状态变为True。

root@k8scludes1:~/cert-manager# kubectl get certificate -o wide
NAME             READY   SECRET               ISSUER              STATUS                                          AGE
cert-zheli-com   True    cert-zheli-com-tls   letsencrypt-dns01   Certificate is up to date and has not expired   10m

secret由cert-zheli-com-btt2t变为cert-zheli-com-tls,现在证书就在cert-zheli-com-tls里面了。

root@k8scludes1:~/cert-manager# kubectl get secrets -o wide
NAME                  TYPE                                  DATA   AGE
cert-zheli-com-tls    kubernetes.io/tls                     2      11m
default-token-mxb4r   kubernetes.io/service-account-token   3      7d8h
test-tls-secret       kubernetes.io/tls                     2      3d9h

六.配置ingress使用证书

删除存在的ingress规则。

root@k8scludes1:~/cert-manager# kubectl get ingress
NAME         CLASS    HOSTS            ADDRESS           PORTS     AGE
my-ingress   <none>   www.nginxx.com   192.168.110.129   80, 443   30h

root@k8scludes1:~/cert-manager# kubectl delete ingress my-ingress 
ingress.networking.k8s.io "my-ingress" deleted

root@k8scludes1:~/cert-manager# kubectl get ingress
No resources found in tls-ingress namespace.

修改ingress规则,- www.rengshengdezheli.xyz表示申请的证书只给www.rengshengdezheli.xyz这个域名用,secretName: cert-zheli-com-tls表示证书放在cert-zheli-com-tls这个secret里。

root@k8scludes1:~/cert-manager# vim ingress-rule.yaml 

root@k8scludes1:~/cert-manager# cat ingress-rule.yaml 
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    kubernetes.io/ingress.class: "nginx"
spec:
  tls: 
  - hosts: 
    - www.rengshengdezheli.xyz
    secretName: cert-zheli-com-tls
  rules:
  - host: www.rengshengdezheli.xyz
    http:
      paths:
      #访问网址目录
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx1svc
            port:
              number: 80
      - path: /ingress
        pathType: Prefix
        backend:
          service:
            name: nginx3svc
            port:
              number: 80
      - path: /n2
        pathType: Prefix
        backend:
          service:
            name: nginx2svc
            port:
              number: 80

应用ingress规则。

root@k8scludes1:~/cert-manager# kubectl apply -f ingress-rule.yaml 
ingress.networking.k8s.io/my-ingress created

root@k8scludes1:~/cert-manager# kubectl get ingress -o wide
NAME         CLASS    HOSTS                      ADDRESS   PORTS     AGE
my-ingress   <none>   www.rengshengdezheli.xyz             80, 443   9s

查看svc,443端口映射为31473了。

root@k8scludes1:~/cert-manager# kubectl get svc -o wide -n ingress-nginx
NAME                                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE    SELECTOR
ingress-nginx-controller             NodePort    10.98.61.146    <none>        80:31853/TCP,443:31473/TCP   5d7h   app.kubernetes.io/component=controller,app.kubernetes.io/instance=ingress-nginx,app.kubernetes.io/name=ingress-nginx
ingress-nginx-controller-admission   ClusterIP   10.102.212.60   <none>        443/TCP                      5d7h   app.kubernetes.io/component=controller,app.kubernetes.io/instance=ingress-nginx,app.kubernetes.io/name=ingress-nginx

七.客户端访问ingress服务

7.1 Windows客户端访问ingress服务

证书申请下来之后,使用Windows客户端访问ingress服务。

注意:C:/Windows/System32/drivers/etc/HOSTS里的IP域名映射也要修改。内容修改如下,192.168.110.129是ingress-nginx-controller所在的机器IP。

192.168.110.129 www.rengshengdezheli.xyz

浏览器访问https://www.rengshengdezheli.xyz:31473/,可以发现现在浏览器访问https://www.rengshengdezheli.xyz:31473/没有警告了。

查看证书,显示连接是安全的。

点击查看证书信息。

可以看到详细的证书信息。

7.2 Linux客户端访问ingress服务

下面使用Linux客户端访问ingress服务,可以看到证书颁发机构:issuer: CN=R3,O=Let's Encrypt,C=US。

[root@etcd2 ~]# curl https://www.rengshengdezheli.xyz:31473/
111

[root@etcd2 ~]# curl -kv https://www.rengshengdezheli.xyz:31473/
* About to connect() to www.rengshengdezheli.xyz port 31473 (#0)
*   Trying 192.168.110.129...
* Connected to www.rengshengdezheli.xyz (192.168.110.129) port 31473 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* skipping SSL peer certificate verification
* SSL connection using TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
* Server certificate:
* 	subject: CN=www.rengshengdezheli.xyz
* 	start date: 4月 25 16:11:21 2022 GMT
* 	expire date: 7月 24 16:11:20 2022 GMT
* 	common name: www.rengshengdezheli.xyz
* 	issuer: CN=R3,O=Let's Encrypt,C=US
> GET / HTTP/1.1
> User-Agent: curl/7.29.0
> Host: www.rengshengdezheli.xyz:31473
> Accept: */*
> 
< HTTP/1.1 200 OK
< Date: Mon, 25 Apr 2022 17:51:19 GMT
< Content-Type: text/html
< Content-Length: 4
< Connection: keep-alive
< Last-Modified: Mon, 25 Apr 2022 17:34:19 GMT
< ETag: "6266db9b-4"
< Accept-Ranges: bytes
< Strict-Transport-Security: max-age=15724800; includeSubDomains
< 
111
* Connection #0 to host www.rengshengdezheli.xyz left intact

八.配置clusterissuer自动申请证书

上一步,我们申请证书的步骤是创建certificate,然后clusterissuer使用certificate申请证书,最后带有certificate信息的secret和ingress一起使用。

我们现在使用另外一种方法,创建ingress的时候自动让clusterissuer申请证书,不用创建certificate yaml文件。

删除证书。

root@k8scludes1:~/cert-manager# kubectl get certificate
NAME             READY   SECRET               AGE
cert-zheli-com   True    cert-zheli-com-tls   48m

root@k8scludes1:~/cert-manager# kubectl delete certificate cert-zheli-com 
certificate.cert-manager.io "cert-zheli-com" deleted

root@k8scludes1:~/cert-manager# kubectl get certificate
No resources found in tls-ingress namespace.

删除secret。

root@k8scludes1:~/cert-manager# kubectl get secrets 
NAME                  TYPE                                  DATA   AGE
cert-zheli-com-tls    kubernetes.io/tls                     2      47m
default-token-mxb4r   kubernetes.io/service-account-token   3      7d8h
test-tls-secret       kubernetes.io/tls                     2      3d9h

root@k8scludes1:~/cert-manager# kubectl delete secrets cert-zheli-com-tls 
secret "cert-zheli-com-tls" deleted

root@k8scludes1:~/cert-manager# kubectl get secrets 
NAME                  TYPE                                  DATA   AGE
default-token-mxb4r   kubernetes.io/service-account-token   3      7d8h
test-tls-secret       kubernetes.io/tls                     2      3d9h

修改ingress规则,添加cert-manager.io/cluster-issuer: "letsencrypt-dns01"表示使用名为letsencrypt-dns01的clusterissuer申请证书。

当我们创建ingress规则之后,会自动使用名为letsencrypt-dns01的clusterissuer申请证书,申请的证书放在名为cert-zheli-com-tls的secret里。

root@k8scludes1:~/cert-manager# vim ingress-rule.yaml 

root@k8scludes1:~/cert-manager# cat ingress-rule.yaml 
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    kubernetes.io/ingress.class: "nginx"
    cert-manager.io/cluster-issuer: "letsencrypt-dns01"
spec:
  tls: 
  - hosts: 
    - www.rengshengdezheli.xyz
    secretName: cert-zheli-com-tls
  rules:
  - host: www.rengshengdezheli.xyz
    http:
      paths:
      #访问网址目录
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx1svc
            port:
              number: 80
      - path: /ingress
        pathType: Prefix
        backend:
          service:
            name: nginx3svc
            port:
              number: 80
      - path: /n2
        pathType: Prefix
        backend:
          service:
            name: nginx2svc
            port:
              number: 80

现在没有证书。

root@k8scludes1:~/cert-manager# kubectl get certificate
No resources found in tls-ingress namespace.

root@k8scludes1:~/cert-manager# kubectl get secrets 
NAME                  TYPE                                  DATA   AGE
default-token-mxb4r   kubernetes.io/service-account-token   3      7d9h
test-tls-secret       kubernetes.io/tls                     2      3d10h

删除以前的ingress规则。

root@k8scludes1:~/cert-manager# kubectl get ingress
NAME         CLASS    HOSTS                      ADDRESS           PORTS     AGE
my-ingress   <none>   www.rengshengdezheli.xyz   192.168.110.129   80, 443   53m

root@k8scludes1:~/cert-manager# kubectl delete ingress my-ingress 
ingress.networking.k8s.io "my-ingress" deleted
root@k8scludes1:~/cert-manager# kubectl get ingress
No resources found in tls-ingress namespace.

创建ingress规则。

root@k8scludes1:~/cert-manager# kubectl apply -f ingress-rule.yaml 
ingress.networking.k8s.io/my-ingress created

root@k8scludes1:~/cert-manager# kubectl get ingress -o wide
NAME         CLASS    HOSTS                      ADDRESS   PORTS     AGE
my-ingress   <none>   www.rengshengdezheli.xyz             80, 443   9s

现在创建ingress规则之后,就自动申请了证书了。

root@k8scludes1:~/cert-manager# kubectl get certificate -o wide
NAME                 READY   SECRET               ISSUER              STATUS                                          AGE
cert-zheli-com-tls   True    cert-zheli-com-tls   letsencrypt-dns01   Certificate is up to date and has not expired   21s

root@k8scludes1:~/cert-manager# kubectl get secrets -o wide
NAME                  TYPE                                  DATA   AGE
cert-zheli-com-tls    kubernetes.io/tls                     2      47s
default-token-mxb4r   kubernetes.io/service-account-token   3      7d9h
test-tls-secret       kubernetes.io/tls                     2      3d10h


root@k8scludes1:~/cert-manager# kubectl get clusterissuers.cert-manager.io -o wide
NAME                READY   STATUS                                                 AGE
letsencrypt-dns01   True    The ACME account was registered with the ACME server   5h37m

证书到期之后,clusterissuers会自动给我们续约的。

可以查看我们创建的clusterissuer的yaml文件。

root@k8scludes1:~/cert-manager# kubectl get clusterissuers.cert-manager.io letsencrypt-dns01 -o yaml >letsencrypt-dns01.yaml

root@k8scludes1:~/cert-manager# cat letsencrypt-dns01.yaml 
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"cert-manager.io/v1","kind":"ClusterIssuer","metadata":{"annotations":{},"name":"letsencrypt-dns01"},"spec":{"acme":{"privateKeySecretRef":{"name":"letsencrypt-dns01"},"server":"https://acme-v02.api.letsencrypt.org/directory","solvers":[{"dns01":{"cloudflare":{"apiTokenSecretRef":{"key":"api-token","name":"cloudflare-api-token-secret"},"email":"[email protected]"}}}]}}}
  creationTimestamp: "2022-04-25T12:51:49Z"
  generation: 1
  name: letsencrypt-dns01
  resourceVersion: "389137"
  uid: 61ef0780-8889-486f-8fa7-a68ba0ce72da
spec:
  acme:
    preferredChain: ""
    privateKeySecretRef:
      name: letsencrypt-dns01
    server: https://acme-v02.api.letsencrypt.org/directory
    solvers:
    - dns01:
        cloudflare:
          apiTokenSecretRef:
            key: api-token
            name: cloudflare-api-token-secret
          email: [email protected]
status:
  acme:
    uri: https://acme-v02.api.letsencrypt.org/acme/acct/515015057
  conditions:
  - lastTransitionTime: "2022-04-25T12:51:52Z"
    message: The ACME account was registered with the ACME server
    observedGeneration: 1
    reason: ACMEAccountRegistered
    status: "True"
    type: Ready

九.没有域名的情况下申请证书

上面方法需要买一个域名才能进行,当我们没有域名的时候,也可以模拟使用cert-manager申请证书。

没有域名的情况下申请证书思路:先模拟一个CA(CA是权威机构),创建一个clusterissuer,再创建一个certificate去向CA申请证书。

删除clusterissuer。

root@k8scludes1:~# kubectl get clusterissuers.cert-manager.io 
NAME                READY   AGE
letsencrypt-dns01   True    14h

root@k8scludes1:~# kubectl delete clusterissuers.cert-manager.io letsencrypt-dns01 
clusterissuer.cert-manager.io "letsencrypt-dns01" deleted

删除证书。

root@k8scludes1:~# kubectl get certificate
NAME                 READY   SECRET               AGE
cert-zheli-com-tls   True    cert-zheli-com-tls   8h

root@k8scludes1:~# kubectl delete certificate cert-zheli-com-tls 
certificate.cert-manager.io "cert-zheli-com-tls" deleted

删除secret。

root@k8scludes1:~# kubectl get secrets 
NAME                  TYPE                                  DATA   AGE
cert-zheli-com-tls    kubernetes.io/tls                     2      8h
default-token-mxb4r   kubernetes.io/service-account-token   3      7d18h
test-tls-secret       kubernetes.io/tls                     2      3d18h

root@k8scludes1:~# kubectl delete secrets cert-zheli-com-tls 
secret "cert-zheli-com-tls" deleted

删除ingress。

root@k8scludes1:~/cert-manager# kubectl get ingress
NAME         CLASS    HOSTS                      ADDRESS           PORTS     AGE
my-ingress   <none>   www.rengshengdezheli.xyz   192.168.110.129   80, 443   9h

root@k8scludes1:~/cert-manager# kubectl delete ingress my-ingress 
ingress.networking.k8s.io "my-ingress" deleted

上一篇博客《 Kubernetes集群中配置Ingress支持HTTPS访问(一):cfssl 》里,我们已经创建了CA的证书(ca.pem)和ca的私钥(ca-key.pem)。

root@k8scludes1:~# cd TLS-ingress/tls/

root@k8scludes1:~/TLS-ingress/tls# ls
ca-config.json  ca.csr  ca-csr.json  ca-key.pem  ca.pem  test.csr  test-csr.json  test-key.pem  test.pem

把CA的证书和密钥写入到 secret里,创建一个tls类型的secret,里面包含CA证书,CA私钥。

root@k8scludes1:~/TLS-ingress/tls# kubectl create secret tls ca-secret --cert=ca.pem --key=ca-key.pem --namespace=cert-manager 
secret/ca-secret created

root@k8scludes1:~/TLS-ingress/tls# kubectl get secrets -o wide -n cert-manager 
NAME                                  TYPE                                  DATA   AGE
ca-secret                             kubernetes.io/tls                     2      16s
cert-manager-cainjector-token-ltxpd   kubernetes.io/service-account-token   3      34h
cert-manager-token-k5s55              kubernetes.io/service-account-token   3      34h
cert-manager-webhook-ca               Opaque                                3      34h
cert-manager-webhook-token-x94pp      kubernetes.io/service-account-token   3      34h
cloudflare-api-token-secret           Opaque                                1      14h
default-token-wl2sx                   kubernetes.io/service-account-token   3      34h
letsencrypt-dns01                     Opaque                                1      14h

现在模拟的CA已经创建好了,接下来创建clusterissuer。

namespace: cert-manager这个可以不写,因为ClusterIssuer是全局的,无所谓命名空间,secretName: ca-secret指定ca证书放在哪个secret里面。

root@k8scludes1:~/TLS-ingress/tls# cd ~/cert-manager/

root@k8scludes1:~/cert-manager# vim clusterissuer-moni.yaml 

root@k8scludes1:~/cert-manager# cat clusterissuer-moni.yaml 
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  #ClusterIssuer名字
  name: letsencrypt-ca-moni
  namespace: cert-manager
spec:
  ca:
    secretName: ca-secret

用自己创建的CA模拟签发机构。

创建clusterissuer。

root@k8scludes1:~/cert-manager# kubectl apply -f clusterissuer-moni.yaml 
clusterissuer.cert-manager.io/letsencrypt-ca-moni created

root@k8scludes1:~/cert-manager# kubectl get clusterissuer -o wide
NAME                  READY   STATUS                AGE
letsencrypt-ca-moni   True    Signing CA verified   21s

修改certificate配置文件。

root@k8scludes1:~/cert-manager# vim certificate-moni.yaml 

root@k8scludes1:~/cert-manager# cat certificate-moni.yaml 
apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  #name: cert-zheli-com-moni表示申请到证书命名为cert-zheli-com-moni
  name: cert-zheli-com-moni
spec:
  dnsNames:
  - www.rengshengdezheli.xyz
  issuerRef:
    kind: ClusterIssuer
    #name: letsencrypt-ca-moni表示使用letsencrypt-ca-moni这个clusterissuer申请证书
    name: letsencrypt-ca-moni 
  #secretName: cert-zheli-com-moni-tls表示申请到的证书放在cert-zheli-com-moni-tls这个secret里
  secretName: cert-zheli-com-moni-tls 

申请证书。

root@k8scludes1:~/cert-manager# kubectl apply -f certificate-moni.yaml 
certificate.cert-manager.io/cert-zheli-com-moni created

现在已经向我们自己创建的CA申请到证书了。

root@k8scludes1:~/cert-manager# kubectl get certificate -o wide
NAME                  READY   SECRET                    ISSUER                STATUS                                          AGE
cert-zheli-com-moni   True    cert-zheli-com-moni-tls   letsencrypt-ca-moni   Certificate is up to date and has not expired   18s

证书在cert-zheli-com-moni-tls里面。

root@k8scludes1:~/cert-manager# kubectl get secrets -o wide
NAME                      TYPE                                  DATA   AGE
cert-zheli-com-moni-tls   kubernetes.io/tls                     3      93s
default-token-mxb4r       kubernetes.io/service-account-token   3      7d18h
test-tls-secret           kubernetes.io/tls                     2      3d19h

修改ingress规则,- www.rengshengdezheli.xyz表示申请到的证书只能用于www.rengshengdezheli.xyz这个域名,secretName: cert-zheli-com-moni-tls表示证书放在cert-zheli-com-moni-tls这个secret里。

root@k8scludes1:~/cert-manager# vim ingress-rule-moni.yaml 

root@k8scludes1:~/cert-manager# cat ingress-rule-moni.yaml 
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
  annotations:
    kubernetes.io/ingress.class: "nginx"
spec:
  tls: 
  - hosts: 
    - www.rengshengdezheli.xyz
    secretName: cert-zheli-com-moni-tls
  rules:
  - host: www.rengshengdezheli.xyz
    http:
      paths:
      #访问网址目录
      - path: /
        pathType: Prefix
        backend:
          service:
            name: nginx1svc
            port:
              number: 80
      - path: /ingress
        pathType: Prefix
        backend:
          service:
            name: nginx3svc
            port:
              number: 80
      - path: /n2
        pathType: Prefix
        backend:
          service:
            name: nginx2svc
            port:
              number: 80

应用ingress规则。

root@k8scludes1:~/cert-manager# kubectl get ingress
No resources found in tls-ingress namespace.

root@k8scludes1:~/cert-manager# kubectl apply -f ingress-rule-moni.yaml 
ingress.networking.k8s.io/my-ingress created

root@k8scludes1:~/cert-manager# kubectl get ingress -o wide
NAME         CLASS    HOSTS                      ADDRESS           PORTS     AGE
my-ingress   <none>   www.rengshengdezheli.xyz   192.168.110.129   80, 443   11s

查看svc,443端口映射为31473。

root@k8scludes1:~/cert-manager# kubectl get svc -o wide -n ingress-nginx
NAME                                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE     SELECTOR
ingress-nginx-controller             NodePort    10.98.61.146    <none>        80:31853/TCP,443:31473/TCP   5d18h   app.kubernetes.io/component=controller,app.kubernetes.io/instance=ingress-nginx,app.kubernetes.io/name=ingress-nginx
ingress-nginx-controller-admission   ClusterIP   10.102.212.60   <none>        443/TCP                      5d18h   app.kubernetes.io/component=controller,app.kubernetes.io/instance=ingress-nginx,app.kubernetes.io/name=ingress-nginx

下面使用Windows客户端访问ingress服务。

这次我们使用Ie浏览器访问: https://www.rengshengdezheli.xyz:31473/ingress/,访问成功。

查看证书。

可以看到这个证书是我们自定义的证书。

十.总结

通过使用Let's Encrypt和cert-manager工具,我们可以在Kubernetes集群中配置Ingress支持HTTPS访问。这样可以为我们的应用程序提供更高的安全性,保护数据传输的机密性和完整性。

热门手游下载