Setting up knative

Installing and configure the doctl tool. Then setup a cluster:

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  doctl kubernetes cluster create gratitude \
      --auto-upgrade \
      "--node-pool=name=default;min-nodes=1;max-nodes=10;size=s-4vcpu-8gb;auto-scale=true"

Once that's in place, make sure that you have a domain, in my case gitgratitude.com:

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  doctl compute domain create gitgratitude.com

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kubectl apply -f https://github.com/knative/operator/releases/download/knative-v1.0.0/operator.yaml

Check status:

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kubectl get deployment knative-operator

NAME               READY   UP-TO-DATE   AVAILABLE   AGE
knative-operator   1/1     1            1           24h

We will now tell the operator to deploy knative serving, and we will use kourier, and set our domain to gitgratitude.com:

serving.yml:

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  apiVersion: v1
  kind: Namespace
  metadata:
    name: knative-serving
  ---
  apiVersion: operator.knative.dev/v1alpha1
  kind: KnativeServing
  metadata:
    name: knative-serving
    namespace: knative-serving
  spec:
    ingress:
      kourier:
        enabled: true
    config:
      network:
        ingress.class: "kourier.ingress.networking.knative.dev"
      domain:
        gitgratitude.com: ""

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  kubectl apply -f serving.yaml

namespace/knative-serving configured
knativeserving.operator.knative.dev/knative-serving configured

And to see what the status of the deployment is:

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kubectl get deployment -n knative-serving

Lets add the default domain serving as well.

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  kubectl apply -f https://github.com/knative/serving/releases/download/knative-v1.0.0/serving-default-domain.yaml

job.batch/default-domain created
service/default-domain-service created

This tells knative to use the certmanager when services get created/deleted:

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  kubectl apply --filename https://github.com/knative/net-certmanager/releases/download/knative-v1.0.0/release.yaml

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  apiVersion: v1
  kind: ConfigMap
  metadata:
    name: config-certmanager
    namespace: knative-serving
    labels:
      networking.knative.dev/certificate-provider: cert-manager
  data:
    issuerRef: |
      kind: ClusterIssuer
      name: letsencrypt-staging      

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  kubectl apply -f cert-config.yaml

configmap/config-certmanager configured

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apiVersion: v1
kind: ConfigMap
metadata:
  name: config-gc
  namespace: knative-serving
data:
  max-non-active-revisions: "1"
  retain-since-create-time: "disabled"
  retain-since-last-active-time: "disabled"

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  kubectl apply -f gc.yaml

configmap/config-gc configured

Create certs.yaml to define how we interact with let-encrypt. I'm going to use the http challenge here.

Also replace wschenk@gmail.com with your email address.

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  apiVersion: cert-manager.io/v1
  kind: ClusterIssuer
  metadata:
    name: letsencrypt-staging
  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: wschenk@gmail.com
      server: https://acme-staging-v02.api.letsencrypt.org/directory
      privateKeySecretRef:
        # Secret resource that will be used to store the account's private key.
        name: staging-issuer-account-key
      # Add a single challenge solver, HTTP01 using nginx
      solvers:
      - http01:
          ingress:
            class: istio #.ingress.networking.knative.dev
  ---
  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: wschenk@gmail.com
      server: https://acme-v02.api.letsencrypt.org/directory
      privateKeySecretRef:
        # Secret resource that will be used to store the account's private key.
        name: prod-issuer-account-key
      # Add a single challenge solver, HTTP01 using nginx
      solvers:
      - http01:
          ingress:
            class: istio
            #.ingress.networking.knative.dev

Then apply it:

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  kubectl apply -f certs.yaml

My domain is gitgratitude.com – you should use yours.

Check above where we setup knative-serving.

Turn on auto-tls and autocreate-cluster-domain-claims:

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  kubectl patch configmap config-network --namespace knative-serving -p '{"data":{"auto-tls":"Enabled","autocreate-cluster-domain-claims":"true"}}'

configmap/config-network patched (no change)

Get the IP

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  kubectl --namespace knative-serving get service kourier -o json| jq ".status.loadBalancer.ingress[0].ip"

"143.244.212.121"

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  doctl compute domain records create gitgratitude.com --record-type A --record-data 143.244.212.121 --record-name default

ID           Type    Name       Data               Priority    Port    TTL     Weight
280306756    A       default    143.244.212.121    0           0       1800    0

Then setup a wildcard CNAME to point to the root.

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  doctl compute domain records create gitgratitude.com --record-type CNAME --record-data default\. --record-name \*.default

ID           Type     Name         Data                        Priority    Port    TTL     Weight
280306923    CNAME    *.default    default.gitgratitude.com    0           0       1800    0

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kn service ls

NAME            URL                                              LATEST                AGE    CONDITIONS   READY   REASON
helloworld-go   https://helloworld-go.default.gitgratitude.com   helloworld-go-00001   114s   3 OK / 3     True    

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kubectl get certificates

NAME                                         READY   SECRET                                       AGE
route-7bbf3267-6eb1-4516-bbb8-e65d81e0b968   True    route-7bbf3267-6eb1-4516-bbb8-e65d81e0b968   62s

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  curl --insecure -vvI https://helloworld-go.default.gitgratitude.com 2>&1 | \
      awk 'BEGIN { cert=0 } /^\* SSL connection/ { cert=1 } /^\*/ { if (cert) print }'

* SSL connection using TLSv1.2 / ECDHE-RSA-CHACHA20-POLY1305
* ALPN, server accepted to use h2
* Server certificate:
*  subject: CN=helloworld-go.default.gitgratitude.com
*  start date: Dec  7 10:28:31 2021 GMT
*  expire date: Mar  7 10:28:30 2022 GMT
*  issuer: C=US; O=(STAGING) Let's Encrypt; CN=(STAGING) Artificial Apricot R3
*  SSL certificate verify result: unable to get local issuer certificate (20), continuing anyway.
* Using HTTP2, server supports multi-use
* Connection state changed (HTTP/2 confirmed)
* Copying HTTP/2 data in stream buffer to connection buffer after upgrade: len=0
* Using Stream ID: 1 (easy handle 0x120012a00)
* Connection state changed (MAX_CONCURRENT_STREAMS == 2147483647)!
* Connection #0 to host helloworld-go.default.gitgratitude.com left intact