Merge ~mthaddon/charm-k8s-ingress/+git/charm-k8s-ingress:ingress-class into charm-k8s-ingress:master

[Tom Haddon]

Add ingress-class to allow user to target the correct ingress controller if their cluster has multiple

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision 42cc842963c8d790b111d3ba331578bf6f7e8c55

diff --git a/config.yaml b/config.yaml
index 9a9b7cf..5f0c3a4 100644
--- a/config.yaml
+++ b/config.yaml
@@ -1,6 +1,16 @@
 # Copyright 2021 Canonical Ltd.
 # See LICENSE file for licensing details.
 options:
+  ingress-class:
+    default: ""
+    description: >
+      The ingress class annotation to target for this ingress resource. If your
+      kubernetes cluster has multiple ingress controllers, this allows you to
+      target the correct one. See https://kubernetes.github.io/ingress-nginx/user-guide/multiple-ingress/
+      for more details. Leaving empty will mean the "kubernetes.io/ingress.class"
+      annotation is unset. This value isn't available to be set via the relation
+      as it's a deploy-time configuration item.
+    type: string
   kube-config:
     default: ""
     description: k8s config. If you're using microk8s, this should be the output of `microk8s config`.
diff --git a/src/charm.py b/src/charm.py
index e14f76a..9f84ece 100755
--- a/src/charm.py
+++ b/src/charm.py
@@ -227,6 +227,10 @@ class IngressCharm(CharmBase):
         else:
             annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 
+        # Run-time configuration options.
+        if self.config["ingress-class"]:
+            annotations["kubernetes.io/ingress.class"] = self.config["ingress-class"]
+
         return kubernetes.client.NetworkingV1beta1Ingress(
             api_version="networking.k8s.io/v1beta1",
             kind="Ingress",
diff --git a/tests/unit/test_charm.py b/tests/unit/test_charm.py
index ac2f0c5..9dda0c1 100644
--- a/tests/unit/test_charm.py
+++ b/tests/unit/test_charm.py
@@ -336,9 +336,11 @@ class TestCharm(unittest.TestCase):
         )
         self.harness.update_config({"tls-secret-name": "gunicorn_tls"})
         self.assertEqual(self.harness.charm._get_k8s_ingress(), expected)
-        # Test max_body_size, retry_http_errors and session-cookie-max-age config options.
+        # Test ingress-class, max_body_size, retry_http_errors and
+        # session-cookie-max-age config options.
         self.harness.update_config(
             {
+                "ingress-class": "nginx",
                 "max-body-size": 20,
                 "retry-errors": "error,timeout,http_502,http_503",
                 "session-cookie-max-age": 3600,
@@ -351,6 +353,7 @@ class TestCharm(unittest.TestCase):
             metadata=kubernetes.client.V1ObjectMeta(
                 name="gunicorn-ingress",
                 annotations={
+                    "kubernetes.io/ingress.class": "nginx",
                     "nginx.ingress.kubernetes.io/affinity": "cookie",
                     "nginx.ingress.kubernetes.io/affinity-mode": "balanced",
                     "nginx.ingress.kubernetes.io/proxy-body-size": "20m",