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Facilitate a webhook integration for leveraging the STACKIT DNS alongsideitsAPI to act as a DNS01ACME Issuer withcert-manager.

helm repo add stackit-cert-manager-webhook https://stackitcloud.github.io/stackit-cert-manager-webhookhelm install stackit-cert-manager-webhook --namespace cert-manager stackit-cert-manager-webhook/stackit-cert-manager-webhook

1. Initiation of STACKIT Authentication Token Secret:

   kubectl create secret generic stackit-sa-authentication \  -n cert-manager \  --from-literal=auth-token=<STACKIT AUTH TOKEN>

   Or alternatively we can utilize the STACKIT service account path authentication:

   kubectl create secret generic stackit-sa-authentication \  -n cert-manager \  --from-literal=sa.json='{"id": "4e1fe486-b463-4bcd-9210-288854268e34","publicKey": "-----BEGIN PUBLIC KEY-----\nPUBLIC_KEY\n-----END PUBLIC KEY-----","createdAt": "2024-04-02T13:12:17.678+00:00","validUntil": "2024-04-15T22:00:00.000+00:00","keyType": "USER_MANAGED","keyOrigin": "GENERATED","keyAlgorithm": "RSA_2048","active": true,"credentials": {  "kid": "kid",  "iss": "iss",  "sub": "sub",  "aud": "aud",  "privateKey": "-----BEGIN PRIVATE KEY-----\nPRIVATE-KEY==\n-----END PRIVATE KEY-----"}}'

   You now need to adjust the deployment via helm to use the secret:

   helm upgrade stackit-cert-manager-webhook \  --namespace cert-manager \  stackit-cert-manager-webhook/stackit-cert-manager-webhook \ --set stackitSaAuthentication.enabled=true

2. Configuration of ClusterIssuer/Issuer:
   For scenarios wherein zones and record sets are encapsulated within a singular project, utilize a ClusterIssuer:

   apiVersion:cert-manager.io/v1kind:ClusterIssuermetadata:name:letsencrypt-prodspec:acme:server:https://acme-v02.api.letsencrypt.org/directoryemail:example@example.com# Replace this with your email addressprivateKeySecretRef:name:letsencrypt-prodsolvers:    -dns01:webhook:solverName:stackitgroupName:acme.stackit.deconfig:projectId:<STACKIT PROJECT ID>

   For diverse project architectures where zones are spread across varying projects, necessitating distinctauthentication tokens per project, the Issuer configuration becomes pertinent. This approach inherentlytethers namespaces to individual projects.

   kubectl create secret generic stackit-cert-manager-webhook \  --namespace=default \  --from-literal=auth-token=<STACKIT AUTH TOKEN>

   apiVersion:cert-manager.io/v1kind:Issuermetadata:name:letsencrypt-prodnamespace:defaultspec:acme:server:https://acme-v02.api.letsencrypt.org/directoryemail:example@example.com# Replace this with your email addressprivateKeySecretRef:name:letsencrypt-prodsolvers:    -dns01:webhook:solverName:stackitgroupName:acme.stackit.deconfig:projectId:<STACKIT PROJECT ID>authTokenSecretNamespace:default

   Note: Ensure the creation of an authentication token secret within the namespace linked to the issuer.The secret must be vested with permissions to access zones in the stipulated project configuration.

3. Demonstration of Ingress Integration with Wildcard SSL/TLS Certificate Generation
   Given the preceding configuration, it is possible to exploit the capabilities of the Issuer or ClusterIssuer todynamically produce wildcard SSL/TLS certificates in the following manner:

   apiVersion:cert-manager.io/v1kind:Certificatemetadata:name:wildcard-examplenamespace:defaultspec:secretName:wildcard-example-tlsissuerRef:name:letsencrypt-prodkind:IssuercommonName:'*.example.runs.onstackit.cloud'# project must be the owner of this zoneduration:8760h0m0sdnsNames:    -example.runs.onstackit.cloud    -'*.example.runs.onstackit.cloud'---apiVersion:networking.k8s.io/v1kind:Ingressmetadata:name:app-ingressnamespace:defaultannotations:ingress.kubernetes.io/rewrite-target:/kubernetes.io/ingress.class:"nginx"spec:rules:    -host:"app.example.runs.onstackit.cloud"http:paths:          -path:/pathType:Prefixbackend:service:name:webappport:number:80tls:    -hosts:        -"app.example.runs.onstackit.cloud"secretName:wildcard-example-tls

The following table delineates the configuration options available for the STACKIT Cert Manager Webhook:

apiVersion:cert-manager.io/v1kind:Issuermetadata:name:letsencrypt-prodnamespace:defaultspec:acme:server:https://acme-v02.api.letsencrypt.org/directoryemail:example@example.com# Replace this with your email addressprivateKeySecretRef:name:letsencrypt-prodsolvers:      -dns01:webhook:solverName:stackitgroupName:acme.stackit.deconfig:projectId:stringapiBasePath:stringauthTokenSecretRef:stringauthTokenSecretKey:stringauthTokenSecretNamespace:stringserviceAccountKeyPath:stringacmeTxtRecordTTL:int64

• projectId: The unique identifier for the STACKIT project.
• apiBasePath: The base path for the STACKIT DNS API. (Default:https://dns.api.stackit.cloud)
• authTokenSecretRef: The reference to the secret containing the STACKIT authentication token. (Default:stackit-cert-manager-webhook)
• authTokenSecretKey: The key within the secret containing the STACKIT authentication token. (Default: auth-token)
• authTokenSecretNamespace: The namespace of the secret containing the STACKIT authentication token. (Default: cert-manager)
• serviceAccountKeyPath: The path to the service account key file. The file must be mounted into the container.
• acmeTxtRecordTTL: The TTL for the ACME TXT record. (Default: 600)

• Unit Testing:

  maketest

• Unit Testing with Coverage Analysis:

  make coverage

• Linting:

  make lint

• End-to-End Testing Workflow:
  Follow the comprehensive guide availablehere.

Our release pipeline leverages goreleaser for the generation and publishing of release assets.This sophisticated approach ensures the streamlined delivery of:

• Pre-compiled binaries tailored for various platforms.
• Docker images optimized for production readiness.

However, one should be cognizant of the fact that goreleaser doesn't inherently support Helm chart distributionsas part of its conventional workflow. Historically, the incorporation of Helm charts into our releases demanded manualintervention. Post the foundational release generation via goreleaser, the Helm chart was affixed as an asset throughmanual processes.
For those interested in the Helm chart creation mechanics, the process was facilitated via the command:

helm package deploy/stackit

To release a new version of the Helm chart, one must meticulously update the appVersion and (chart)version delineation in theChart.yaml. Post this modification, initiate a new release to encompass these changes.