Improve cert-manager resources for Eventing TLS certs provisioning (#…

…6953)

This PR is refactoring how we provision certificates with cert-manager
in a way that is much easier for organizations to plug their own
root CA or even use a different issuer.

Signed-off-by: Pierangelo Di Pilato <pierdipi@redhat.com>

config/brokers/mt-channel-broker-tls/broker-filter-tls-certificate.yaml

@@ -1,3 +1,17 @@
+# Copyright 2023 The Knative Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 apiVersion: cert-manager.io/v1
 kind: Certificate
 metadata:
@@ -27,6 +41,6 @@ spec:
     - broker-filter.knative-eventing.svc.cluster.local
 
   issuerRef:
-    name: selfsigned-issuer
+    name: selfsigned-ca-issuer
     kind: Issuer
     group: cert-manager.io

config/brokers/mt-channel-broker-tls/broker-ingress-tls-certificate.yaml

@@ -1,3 +1,17 @@
+# Copyright 2023 The Knative Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 apiVersion: cert-manager.io/v1
 kind: Certificate
 metadata:
@@ -27,6 +41,6 @@ spec:
     - broker-ingress.knative-eventing.svc.cluster.local
 
   issuerRef:
-    name: selfsigned-issuer
+    name: selfsigned-ca-issuer
     kind: Issuer
     group: cert-manager.io

config/channels/in-memory-channel-tls/imc-dispatcher-tls-certificate.yaml

@@ -1,3 +1,17 @@
+# Copyright 2023 The Knative Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 apiVersion: cert-manager.io/v1
 kind: Certificate
 metadata:
@@ -27,6 +41,6 @@ spec:
     - imc-dispatcher.knative-eventing.svc.cluster.local
 
   issuerRef:
-    name: selfsigned-issuer
+    name: selfsigned-ca-issuer
     kind: Issuer
     group: cert-manager.io

config/tls/issuers/selfsigned-ca-issuer.yaml

@@ -0,0 +1,23 @@
+# Copyright 2023 The Knative Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This is the issuer that every Eventing component should use to issue their server's certs.
+apiVersion: cert-manager.io/v1
+kind: Issuer
+metadata:
+  name: selfsigned-ca-issuer
+  namespace: knative-eventing
+spec:
+  ca:
+    secretName: eventing-ca

config/tls/issuers/selfsigned-issuer.yaml

@@ -0,0 +1,42 @@
+# Copyright 2023 The Knative Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This is the root issuer to bootstrap the eventing CA.
+apiVersion: cert-manager.io/v1
+kind: Issuer
+metadata:
+  name: selfsigned-issuer
+  namespace: knative-eventing
+spec:
+  selfSigned: {}
+---
+# This is the Eventing CA certificate.
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  name: selfsigned-ca
+  namespace: knative-eventing
+spec:
+  secretName: eventing-ca
+
+  isCA: true
+  commonName: selfsigned-ca
+  privateKey:
+    algorithm: ECDSA
+    size: 256
+
+  issuerRef:
+    name: selfsigned-issuer
+    kind: Issuer
+    group: cert-manager.io