Setting up Traefik v2 and cert-manager on Kapsule

Traefik - Overview

Traefik (pronounced traffic) is a modern HTTP reverse proxy and load balancer designed to make the deploying of microservices easy. Traefik integrates with any HTTP and TCP-based applications and every major cluster technology.

Our goal in this tutorial is to:

  • Expose Traefik 2 using a Scaleway LoadBalancer
  • Deploy a test application on our cluster
  • Expose this test application through an ingress object, using Traefik 2 (deployed by Kapsule)
  • Expose this application securely (with https and Let’s Encrypt, using cert-manager)

This tutorial is divided in two parts:

  • First, we will check how to expose the Traefik 2 ingress controller shipped with Kapsule with a Scaleway LoadBalancer.
  • In the second part, we will deploy a test application expose it in http with a DNS managed by Scaleway DNS, then use cert-manager to create a Let’s Encrypt certificate and expose this application securely in https.

Requirements:

Creating a service to deploy a LoadBalancer in front of Traefik 2

To expose Traefik 2 with a Scaleway LoadBalancer, deploy the following yaml file on your cluster:

1 . Create and open the file traefik-loadbalancer.yml in your favorite text editor and copy the following content into it:

apiVersion: v1
kind: Service
metadata:
  name: traefik-ingress
  namespace: kube-system
  labels:
    k8s.scw.cloud/ingress: traefik2
spec:
  type: LoadBalancer
  ports:
  - port: 80
    name: http
    targetPort: 8000
  - port: 443
    name: https
    targetPort: 8443
  selector:
    app.kubernetes.io/name: traefik

2 . Use kubectl to deploy the configuration:

$ kubectl create -f traefik-loadbalancer.yml
service/traefik-ingress created

3 . Verify that your LoadBalancer has been deployed correctly:

$ kubectl get svc -n kube-system
traefik-ingress   LoadBalancer   10.37.89.202    195.154.68.108   80:30509/TCP,443:32138/TCP   43s

You can see here that the IP address of your LoadBalancer is 195.154.68.108. If you ‘curl’ it you can reach the default backend (saying “404 page not found”) as no ingress objects are created and you are reaching it through the IP address:

$ curl 195.154.68.108
404 page not found

Creating a wildcard DNS record and pointing your domain name to the IP address

We will be using the new DNS product, available on Scaleway Elements, to create a wildcard record pointing to this IP address (the domain used in this tutorial will be “mytest.com”). A wildcard record (*.mydomain.com) allows you to point any sub-domain of your domain to the configured IP address.

Verify that the domain is pointed to the IP address of your LoadBalancer:

$ host foobar.mytest.com
foobar.mytest.com has address 195.154.68.108

Your domain is now pointing to your LoadBalancer IP, you can resolve any of your subdomain with that IP.

Deploying a test application

In this step, we deploy a test application called “tea coffee” which is only printing tea or coffee depending on the subpath you will reach.

1 . Use kubectl to create the application

$ kubectl create -f https://raw.githubusercontent.com/nginxinc/kubernetes-ingress/master/examples/complete-example/cafe.yaml

2 . Create an associated ingress object pointing to teacoffee.mytest.com by creating and editing the file ingress-teacoffee.yml in your favorite text editor:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: cafe-ingress
spec:
  rules:
  - host: teacoffee.mytest.com
    http:
      paths:
      - path: /tea
        pathType: Prefix
        backend:
          service:
            name: tea-svc
            port:
              number: 80
      - path: /coffee
        pathType: Prefix
        backend:
          service:
            name: coffee-svc
            port:
              number: 80

2 . Run the folowing command to setup the configuration:

$ kubectl create -f ingress-teacoffee.yml
ingress.networking.k8s.io/cafe-ingress created

3 . You can now use curl to send a HTTP request this URL. Traefik 2 is working correctly with your wildcard DNS in plain, unencrypted HTTP (web unsecure).

$ curl teacoffee.mytest.com/tea
Server address: 100.64.0.240:8080
Server name: tea-69c99ff568-c2lc2
Date: 29/Jun/2020:13:01:19 +0000
URI: /tea
Request ID: f3b7f1bcd5dd841d420236906146af9f

4 . To proceed with the tutorial, delete the ingress object created. It will be replaced in future steps.

$ kubectl delete ing cafe-ingress

Deploying Cert Manager

Cert-manager is in charge of creating Let’s Encrypt TLS certificates to make your website secure, to sum-up:

  • Create an ingress object for a specific subdomain (for instance foobar.mytest.com)
  • Let’s Encrypt must be sure that the domain belongs to you. For this reason, Let’s Encrypt requests a “challenge”, in our case, an HTTP challenge. Meaning here that Let’s Encrypt will try to reach foobar.mytest.com, and is able to see a specific hash on this page.
  • Cert-manager is serving this page for you by creating an ingress object and using an HTTP server.
  • When the challenge is ok, the certificate is created and added in a certificate object.
  • You can then use this certificate object to serve your website securely (HTTPS).

Note that any modification to the Traefik2 deployed by Kapsule may be overwritten by the reconciliation process, consider installing it yourself for a production usage.

1 . Modify the default Traefik 2 daemonset running on Kapsule to do that, add --providers.kubernetesIngress.ingressClass=traefik-cert-manager in the cmd stanza.

$ kubectl edit ds traefik -n kube-system
daemonset.apps/traefik edited
[]
        - --global.checknewversion
        - --global.sendanonymoususage
        - --entryPoints.traefik.address=:9000
        - --entryPoints.web.address=:8000
        - --entryPoints.websecure.address=:8443
        - --providers.kubernetesIngress.ingressClass=traefik-cert-manager
        - --api.dashboard=true
        - --ping=true
        - --providers.kubernetescrd
        - --providers.kubernetesingress
[]

2 . Delete the existing Traefik pods in order to get the new arguments.

$ kubectl -n kube-system delete pod -l app.kubernetes.io/name=traefik

3 . Use the command below to install cert-manager and its needed CRD (Custom Resource Definitions):

$ kubectl apply --validate=false -f https://github.com/jetstack/cert-manager/releases/download/v1.0.2/cert-manager.yaml
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
customresourcedefinition.apiextensions.k8s.io/clusterissuers.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/issuers.cert-manager.io created
customresourcedefinition.apiextensions.k8s.io/orders.acme.cert-manager.io created
namespace/cert-manager created
serviceaccount/cert-manager-cainjector created
serviceaccount/cert-manager created
serviceaccount/cert-manager-webhook created
clusterrole.rbac.authorization.k8s.io/cert-manager-cainjector created
clusterrole.rbac.authorization.k8s.io/cert-manager-controller-issuers created
clusterrole.rbac.authorization.k8s.io/cert-manager-controller-clusterissuers created
clusterrole.rbac.authorization.k8s.io/cert-manager-controller-certificates created
clusterrole.rbac.authorization.k8s.io/cert-manager-controller-orders created
clusterrole.rbac.authorization.k8s.io/cert-manager-controller-challenges created
clusterrole.rbac.authorization.k8s.io/cert-manager-controller-ingress-shim created
clusterrole.rbac.authorization.k8s.io/cert-manager-view created
clusterrole.rbac.authorization.k8s.io/cert-manager-edit created
clusterrolebinding.rbac.authorization.k8s.io/cert-manager-cainjector created
clusterrolebinding.rbac.authorization.k8s.io/cert-manager-controller-issuers created
clusterrolebinding.rbac.authorization.k8s.io/cert-manager-controller-clusterissuers created
clusterrolebinding.rbac.authorization.k8s.io/cert-manager-controller-certificates created
clusterrolebinding.rbac.authorization.k8s.io/cert-manager-controller-orders created
clusterrolebinding.rbac.authorization.k8s.io/cert-manager-controller-challenges created
clusterrolebinding.rbac.authorization.k8s.io/cert-manager-controller-ingress-shim created
role.rbac.authorization.k8s.io/cert-manager-cainjector:leaderelection created
role.rbac.authorization.k8s.io/cert-manager:leaderelection created
role.rbac.authorization.k8s.io/cert-manager-webhook:dynamic-serving created
rolebinding.rbac.authorization.k8s.io/cert-manager-cainjector:leaderelection created
rolebinding.rbac.authorization.k8s.io/cert-manager:leaderelection created
rolebinding.rbac.authorization.k8s.io/cert-manager-webhook:dynamic-serving created
service/cert-manager created
service/cert-manager-webhook created
deployment.apps/cert-manager-cainjector created
deployment.apps/cert-manager created
deployment.apps/cert-manager-webhook created
mutatingwebhookconfiguration.admissionregistration.k8s.io/cert-manager-webhook created
validatingwebhookconfiguration.admissionregistration.k8s.io/cert-manager-webhook created

Creating the Let's Encrypt issuer

1 . Create a cluster issuer that allow you to specify:

  • the Let’s Encrypt server, if you want to replace the production environment with the staging one.
  • the mail used by Let’s Encrypt to warn you about certificate expiration.

Copy and paste the following configuration in the file cluster-issuer.yaml using your favorite text editor:

apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: letsencrypt-prod
spec:
  acme:
    # You must replace this email address with your own.
    # Let's Encrypt will use this to contact you about expiring
    # certificates, and issues related to your account.
    email: mymail@test.com
    server: https://acme-v02.api.letsencrypt.org/directory
    privateKeySecretRef:
      # Secret resource used to store the account's private key.
      name: issuer-account-key
    # Add a single challenge solver, HTTP01
    solvers:
      - http01:
          ingress:
            class: traefik-cert-manager

2 . Use kubectl to apply the configuration:

$ kubectl create -f cluster-issuer.yaml
clusterissuer.cert-manager.io/letsencrypt-prod created

Creating and using a Let's Encrypt certificate to serve your website in HTTPS

In this step you will create the Let’s Encrypt certificate by specifying:

  • The secret name where the certificate will be stored.
  • The subdomain for which you want to create a certificate.
  • The issuer created before (letsencrypt-prod).

1 . Create a edit a file mycert.yaml as follows:

apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: teacoffee-cert
  namespace: default
spec:
  commonName: teacoffee.mytest.com
  secretName: teacoffee-cert
  dnsNames:
    - teacoffee.mytest.com
  issuerRef:
    name: letsencrypt-prod
    kind: ClusterIssuer

2 . Apply the configuration using kubectl:

$ kubectl create -f mycert.yaml
certificate.cert-manager.io/teacoffee-cert created

3 . Check the certificate has been correctly created (you should see “Ready” in the condition):

$ kubectl describe certificate -n default teacoffee-cert
Spec:
  Common Name:  teacoffee.mytest.org
  Dns Names:
    teacoffee.mytest.org
  Issuer Ref:
    Kind:       ClusterIssuer
    Name:       letsencrypt-prod
  Secret Name:  teacoffee-cert
Status:
  Conditions:
    Last Transition Time:  2020-06-29T13:34:36Z
    Message:               Certificate is up to date and has not expired
    Reason:                Ready
    Status:                True
    Type:                  Ready
  Not After:               2020-09-27T12:34:35Z
Events:
  Type    Reason     Age   From          Message
  ----    ------     ----  ----          -------
  Normal  Requested  11m   cert-manager  Created new CertificateRequest resource "teacoffee-cert-4271191437"
  Normal  Issued     48s   cert-manager  Certificate issued successfully

4 . Create a Traefik IngressRoute, with TLS enabled (with the name of the secret created by the creation of the certificate, in our case teacoffee-cert)

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: testcoffee
  namespace: default
spec:
  entryPoints:
    - websecure
  routes:
    - match: Host(`teacoffee.mytest.com`) && PathPrefix(`/tea`)
      kind: Rule
      services:
        - name: tea-svc
          port: 80
    - match: Host(`teacoffee.mytest.com`) && PathPrefix(`/coffee`)
      kind: Rule
      services:
        - name: coffee-svc
          port: 80
  tls:
    secretName: teacoffee-cert

5 . Check your website is accessible in HTTPS:

curl -v https://teacoffee.mytest.com/tea
*   Trying 195.154.68.108...
* TCP_NODELAY set
* Connected to teacoffee.mytest.com (195.154.68.108) port 443 (#0)
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/certs/ca-certificates.crt
  CApath: /etc/ssl/certs
[..]
* Server certificate:
*  subject: CN=teacoffee.mytest.com
*  start date: Jun 29 12:46:04 2020 GMT
*  expire date: Sep 27 12:46:04 2020 GMT
*  subjectAltName: host "teacoffee.mytest.com" matched cert's "teacoffee.mytest.com"
*  issuer: C=US; O=Let's Encrypt; CN=Let's Encrypt Authority X3
*  SSL certificate verify ok.
[..]
> GET /tea HTTP/2
> Host: teacoffee.mytest.com
> User-Agent: curl/7.58.0
> Accept: */*
> 
[..]
Server address: 100.64.0.240:8080
Server name: tea-69c99ff568-c2lc2
Date: 29/Jun/2020:13:52:42 +0000
URI: /tea
Request ID: b7a45b7b20bd712df75f8ce8596db50d
* Connection #0 to host teacoffee.mytest.com left intact

6 . Access the Traefik 2 dashboard by using this command:

$ kubectl port-forward -n kube-system $(kubectl get pods -n kube-system --selector "app.kubernetes.io/name=traefik" --output=name | head -n 1) 9000:9000

7 . You can then access the Traefik 2 dashboard with this address: http://127.0.0.1:9000/dashboard/ (Note the trailing /.)

To go further, you might be interested in the following pages:

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