From 58ded3184832c7162056f3ebfafd01c6267c74e2 Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Tue, 10 Sep 2024 13:21:27 +0000
Subject: [PATCH 01/10] add configurable replicas to gateway deployment

---
 charms/istio-gateway/config.yaml       |  4 ++++
 charms/istio-gateway/src/charm.py      |  1 +
 charms/istio-gateway/src/manifest.yaml | 12 ++++++++++++
 3 files changed, 17 insertions(+)

diff --git a/charms/istio-gateway/config.yaml b/charms/istio-gateway/config.yaml
index 2dadadeb..54fb1aa1 100644
--- a/charms/istio-gateway/config.yaml
+++ b/charms/istio-gateway/config.yaml
@@ -12,3 +12,7 @@ options:
     default: 'docker.io/istio/proxyv2:1.22.0'
     description: Istio Proxy image
     type: string
+  replicas:
+    default: 1
+    description: Number of replicas for the istio-ingressgateway pods
+    type: int
diff --git a/charms/istio-gateway/src/charm.py b/charms/istio-gateway/src/charm.py
index 3c258b01..22544233 100755
--- a/charms/istio-gateway/src/charm.py
+++ b/charms/istio-gateway/src/charm.py
@@ -94,6 +94,7 @@ def start(self, event):
             pilot_host=pilot["service-name"],
             pilot_port=pilot["service-port"],
             gateway_service_type=self.model.config["gateway_service_type"],
+            replicas=self.model.config["replicas"],
         )
 
         for obj in codecs.load_all_yaml(rendered):
diff --git a/charms/istio-gateway/src/manifest.yaml b/charms/istio-gateway/src/manifest.yaml
index 5fb11c6c..5bbab2b9 100644
--- a/charms/istio-gateway/src/manifest.yaml
+++ b/charms/istio-gateway/src/manifest.yaml
@@ -25,6 +25,18 @@ metadata:
   name: istio-{{ kind }}gateway-workload
   namespace: {{ namespace }}
 spec:
+  replicas: {{ replicas }}
+{% if replicas > 1 %}
+  affinity:
+    podAntiAffinity:
+      requiredDuringSchedulingIgnoredDuringExecution:
+      - labelSelector:
+          matchExpressions:
+          - key: app
+            operator: In
+            values:
+            - istio-{{ kind }}gateway
+{% endif %}
   selector:
     matchLabels:
       app: istio-{{ kind }}gateway

From 556c79d442cdb3633d7a564ed2f1a5aed7486be9 Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Tue, 10 Sep 2024 21:45:02 +0000
Subject: [PATCH 02/10] fix manifest and add topologyKey

---
 charms/istio-gateway/src/manifest.yaml | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/charms/istio-gateway/src/manifest.yaml b/charms/istio-gateway/src/manifest.yaml
index 5bbab2b9..af8b2581 100644
--- a/charms/istio-gateway/src/manifest.yaml
+++ b/charms/istio-gateway/src/manifest.yaml
@@ -26,17 +26,6 @@ metadata:
   namespace: {{ namespace }}
 spec:
   replicas: {{ replicas }}
-{% if replicas > 1 %}
-  affinity:
-    podAntiAffinity:
-      requiredDuringSchedulingIgnoredDuringExecution:
-      - labelSelector:
-          matchExpressions:
-          - key: app
-            operator: In
-            values:
-            - istio-{{ kind }}gateway
-{% endif %}
   selector:
     matchLabels:
       app: istio-{{ kind }}gateway
@@ -66,6 +55,15 @@ spec:
         sidecar.istio.io/inject: "false"
     spec:
       affinity:
+        podAntiAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+          - labelSelector:
+              matchExpressions:
+              - key: app
+                operator: In
+                values:
+                - istio-{{ kind }}gateway
+            topologyKey: kubernetes.io/hostname
         nodeAffinity:
           preferredDuringSchedulingIgnoredDuringExecution: null
           requiredDuringSchedulingIgnoredDuringExecution: null

From 74e6be9273980f12f0ef4f4a03c4bb9dbee27081 Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Tue, 10 Sep 2024 21:45:28 +0000
Subject: [PATCH 03/10] update unit tests data

---
 .../istio-gateway/tests/unit/data/egress-example.yaml  | 10 ++++++++++
 .../istio-gateway/tests/unit/data/ingress-example.yaml | 10 ++++++++++
 2 files changed, 20 insertions(+)

diff --git a/charms/istio-gateway/tests/unit/data/egress-example.yaml b/charms/istio-gateway/tests/unit/data/egress-example.yaml
index a60b4005..4c6a602c 100644
--- a/charms/istio-gateway/tests/unit/data/egress-example.yaml
+++ b/charms/istio-gateway/tests/unit/data/egress-example.yaml
@@ -24,6 +24,7 @@ metadata:
   name: istio-egressgateway-workload
   namespace: None
 spec:
+  replicas: 1
   selector:
     matchLabels:
       app: istio-egressgateway
@@ -53,6 +54,15 @@ spec:
         sidecar.istio.io/inject: "false"
     spec:
       affinity:
+        podAntiAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+          - labelSelector:
+              matchExpressions:
+              - key: app
+                operator: In
+                values:
+                - istio-egressgateway
+            topologyKey: kubernetes.io/hostname
         nodeAffinity:
           preferredDuringSchedulingIgnoredDuringExecution: null
           requiredDuringSchedulingIgnoredDuringExecution: null
diff --git a/charms/istio-gateway/tests/unit/data/ingress-example.yaml b/charms/istio-gateway/tests/unit/data/ingress-example.yaml
index 56b30b0f..2e83fb29 100644
--- a/charms/istio-gateway/tests/unit/data/ingress-example.yaml
+++ b/charms/istio-gateway/tests/unit/data/ingress-example.yaml
@@ -24,6 +24,7 @@ metadata:
   name: istio-ingressgateway-workload
   namespace: None
 spec:
+  replicas: 1
   selector:
     matchLabels:
       app: istio-ingressgateway
@@ -53,6 +54,15 @@ spec:
         sidecar.istio.io/inject: "false"
     spec:
       affinity:
+        podAntiAffinity:
+          requiredDuringSchedulingIgnoredDuringExecution:
+          - labelSelector:
+              matchExpressions:
+              - key: app
+                operator: In
+                values:
+                - istio-ingressgateway
+            topologyKey: kubernetes.io/hostname
         nodeAffinity:
           preferredDuringSchedulingIgnoredDuringExecution: null
           requiredDuringSchedulingIgnoredDuringExecution: null

From 941a60a722d35b62e2ef7e76f214a71c5edb0cd2 Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Tue, 10 Sep 2024 21:46:08 +0000
Subject: [PATCH 04/10] render with replicas on remove

---
 charms/istio-gateway/src/charm.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/charms/istio-gateway/src/charm.py b/charms/istio-gateway/src/charm.py
index 22544233..b1ec9199 100755
--- a/charms/istio-gateway/src/charm.py
+++ b/charms/istio-gateway/src/charm.py
@@ -114,6 +114,7 @@ def remove(self, event):
             proxy_image=self.model.config["proxy-image"],
             pilot_host="foo",
             pilot_port="foo",
+            replicas=self.model.config["replicas"],
         )
 
         try:

From be40474241c5bb345a45711c8f1c366595896fe0 Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Tue, 10 Sep 2024 21:46:25 +0000
Subject: [PATCH 05/10] add integration test for replicas

---
 tests/test_bundle.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/test_bundle.py b/tests/test_bundle.py
index dde7bf27..d7adb60f 100644
--- a/tests/test_bundle.py
+++ b/tests/test_bundle.py
@@ -15,6 +15,7 @@
     create_namespaced_resource,
     load_in_cluster_generic_resources,
 )
+from lightkube.resources.apps_v1 import Deployment
 from pytest_operator.plugin import OpsTest
 
 log = logging.getLogger(__name__)
@@ -332,6 +333,27 @@ async def test_disable_ingress_auth(ops_test: OpsTest):
     )
 
 
+async def test_gateway_replicas_config(ops_test: OpsTest):
+    """Test the replicas config takes effect in the Deployment."""
+
+    replicas_value = "2"
+    await ops_test.model.applications[ISTIO_GATEWAY_APP_NAME].set_config(
+        {"replicas": replicas_value}
+    )
+    await ops_test.model.wait_for_idle(apps=[ISTIO_GATEWAY_APP_NAME], status="active", timeout=300)
+
+    client = lightkube.Client()
+    gateway_deployment = client.get(
+        Deployment, name="istio-ingressgateway-workload", namespace=ops_test.model_name
+    )
+
+    assert gateway_deployment.spec.replicas == int(replicas_value)
+    # TODO: assert antiaffinity contents
+    # assert gateway_deployment.spec.template.spec.affinity == "expected"
+
+    # TODO: assert second pod is not scheduled
+
+
 async def test_charms_removal(ops_test: OpsTest):
     """Test the istio-operators can be removed without errors."""
     # NOTE: the istio-gateway charm has to be removed before istio-pilot since

From a75bb9613ae558a7f5af8acf45fec17c3e0f86f0 Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Thu, 12 Sep 2024 09:28:30 +0000
Subject: [PATCH 06/10] add asserts to integration test

---
 tests/test_bundle.py | 49 +++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 44 insertions(+), 5 deletions(-)

diff --git a/tests/test_bundle.py b/tests/test_bundle.py
index d7adb60f..bfcf00fe 100644
--- a/tests/test_bundle.py
+++ b/tests/test_bundle.py
@@ -16,6 +16,7 @@
     load_in_cluster_generic_resources,
 )
 from lightkube.resources.apps_v1 import Deployment
+from lightkube.resources.core_v1 import Pod
 from pytest_operator.plugin import OpsTest
 
 log = logging.getLogger(__name__)
@@ -47,6 +48,10 @@
     plural="virtualservices",
 )
 
+EXPECTED_LABEL_SELECTOR = (
+    "LabelSelectorRequirement(key='app', operator='In', values=['istio-ingressgateway'])"
+)
+
 
 @pytest.mark.abort_on_fail
 async def test_kubectl_access(ops_test: OpsTest):
@@ -334,7 +339,11 @@ async def test_disable_ingress_auth(ops_test: OpsTest):
 
 
 async def test_gateway_replicas_config(ops_test: OpsTest):
-    """Test the replicas config takes effect in the Deployment."""
+    """Test changing the replicas config to 2, and then:
+    1. Assert the replicas in the Deployment spec went up to 2.
+    2. Assert the Deployment has the antiaffinity rule as expected.
+    3. Assert the new Pod was not scheduled due to only 1 Node being available.
+    """
 
     replicas_value = "2"
     await ops_test.model.applications[ISTIO_GATEWAY_APP_NAME].set_config(
@@ -343,15 +352,45 @@ async def test_gateway_replicas_config(ops_test: OpsTest):
     await ops_test.model.wait_for_idle(apps=[ISTIO_GATEWAY_APP_NAME], status="active", timeout=300)
 
     client = lightkube.Client()
+
+    # Get the gateway Deployment
     gateway_deployment = client.get(
         Deployment, name="istio-ingressgateway-workload", namespace=ops_test.model_name
     )
 
+    # Assert the Deployment has the number of replicas from the config
     assert gateway_deployment.spec.replicas == int(replicas_value)
-    # TODO: assert antiaffinity contents
-    # assert gateway_deployment.spec.template.spec.affinity == "expected"
-
-    # TODO: assert second pod is not scheduled
+    # Assert the Deployment has the correct antiaffinity rule
+    assert (
+        str(
+            gateway_deployment.spec.template.spec.affinity.podAntiAffinity.requiredDuringSchedulingIgnoredDuringExecution[  # noqa E501
+                0
+            ].labelSelector.matchExpressions[
+                0
+            ]
+        )
+        == EXPECTED_LABEL_SELECTOR
+    )
+
+    # List gateway pods that are in Pending status
+    pending_gateway_pods = list(
+        client.list(
+            Pod,
+            namespace=ops_test.model_name,
+            labels={"app": "istio-ingressgateway"},
+            fields={"status.phase": "Pending"},
+        )
+    )
+
+    # Assert one Pod is in Pending status
+    assert len(pending_gateway_pods) == 1
+
+    # Get the status message for the Pending pod
+    pending_gateway_pod = pending_gateway_pods[0]
+    message = pending_gateway_pod.status.conditions[0].message
+
+    # Assert the status message is about anti-affinity
+    assert "didn't match pod anti-affinity rules" in message
 
 
 async def test_charms_removal(ops_test: OpsTest):

From 94f8d74dec1ace68dd09fe1d33ddff51fb01b17c Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Tue, 24 Sep 2024 11:51:19 +0000
Subject: [PATCH 07/10] skip: add unit test and offload integration test

---
 charms/istio-gateway/tests/unit/test_charm.py | 35 +++++++++++++++++++
 tests/test_bundle.py                          |  7 ++--
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/charms/istio-gateway/tests/unit/test_charm.py b/charms/istio-gateway/tests/unit/test_charm.py
index b271f2c0..4764c8e7 100644
--- a/charms/istio-gateway/tests/unit/test_charm.py
+++ b/charms/istio-gateway/tests/unit/test_charm.py
@@ -158,3 +158,38 @@ def test_metrics(harness):
                 }
             ],
         )
+
+
+def test_manifests_applied_with_replicas_config(configured_harness, mocked_client):
+    """
+    Asserts that the Deployment manifest called by `lightkube_client.apply`
+    contains the replicas config value.
+    """
+
+    # Arrange
+    # Reset the mock so that the calls list does not include any calls from other hooks
+    mocked_client.reset_mock()
+
+    # Update the replicas config in the harness
+    replicas_config_value = 2
+    configured_harness.update_config({"replicas": replicas_config_value})
+
+    # Act
+    configured_harness.charm.on.install.emit()
+
+    actual_objects = []
+
+    # Get all the objects called by lightkube client `.apply`
+    for call in mocked_client.return_value.apply.call_args_list:
+        # The first (and only) argument to the apply method is the obj
+        # Convert the object to a dictionary and add it to the list
+        actual_objects.append(call.args[0].to_dict())
+
+    # Filter out the objects with Deployment kind
+    deployments = filter(lambda obj: obj.get("kind") == "Deployment", actual_objects)
+    # The gateway deployment is the only Deployment object in the manifests
+    gateway_deployment = list(deployments)[0]
+
+    # Assert
+    assert gateway_deployment["spec"].get("replicas") == replicas_config_value
+    assert configured_harness.charm.model.unit.status == ActiveStatus("")
diff --git a/tests/test_bundle.py b/tests/test_bundle.py
index bfcf00fe..06adbe0d 100644
--- a/tests/test_bundle.py
+++ b/tests/test_bundle.py
@@ -340,9 +340,8 @@ async def test_disable_ingress_auth(ops_test: OpsTest):
 
 async def test_gateway_replicas_config(ops_test: OpsTest):
     """Test changing the replicas config to 2, and then:
-    1. Assert the replicas in the Deployment spec went up to 2.
-    2. Assert the Deployment has the antiaffinity rule as expected.
-    3. Assert the new Pod was not scheduled due to only 1 Node being available.
+    1. Assert the Deployment has the antiaffinity rule as expected.
+    2. Assert the new Pod was not scheduled due to only 1 Node being available.
     """
 
     replicas_value = "2"
@@ -358,8 +357,6 @@ async def test_gateway_replicas_config(ops_test: OpsTest):
         Deployment, name="istio-ingressgateway-workload", namespace=ops_test.model_name
     )
 
-    # Assert the Deployment has the number of replicas from the config
-    assert gateway_deployment.spec.replicas == int(replicas_value)
     # Assert the Deployment has the correct antiaffinity rule
     assert (
         str(

From bff115fc48e8992d0978f4dbf50d19272d7ddeea Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Mon, 30 Sep 2024 19:32:45 +0000
Subject: [PATCH 08/10] skip: address comment

---
 charms/istio-gateway/tests/unit/test_charm.py | 43 +++++++++++++++++++
 tests/test_bundle.py                          | 26 +----------
 2 files changed, 45 insertions(+), 24 deletions(-)

diff --git a/charms/istio-gateway/tests/unit/test_charm.py b/charms/istio-gateway/tests/unit/test_charm.py
index 4764c8e7..e1806b1a 100644
--- a/charms/istio-gateway/tests/unit/test_charm.py
+++ b/charms/istio-gateway/tests/unit/test_charm.py
@@ -160,6 +160,49 @@ def test_metrics(harness):
         )
 
 
+def test_manifests_applied_with_anti_affinity(configured_harness, kind, mocked_client):
+    """
+    Asserts that the Deployment manifest called by `lightkube_client.apply`
+    contains the correct anti-affinity rule
+    """
+
+    # Arrange
+    # Reset the mock so that the calls list does not include any calls from other hooks
+    mocked_client.reset_mock()
+
+    # Define the expected labelSelector based on the kind
+    expected_label_selector = {"key": "app", "operator": "In", "values": [f"istio-{kind}gateway"]}
+
+    # Act
+    configured_harness.charm.on.start.emit()
+
+    actual_objects = []
+
+    # Get all the objects called by lightkube client `.apply`
+    for call in mocked_client.return_value.apply.call_args_list:
+        # The first (and only) argument to the apply method is the obj
+        # Convert the object to a dictionary and add it to the list
+        actual_objects.append(call.args[0].to_dict())
+
+    # Filter out the objects with Deployment kind
+    deployments = filter(lambda obj: obj.get("kind") == "Deployment", actual_objects)
+    # The gateway deployment is the only Deployment object in the manifests
+    gateway_deployment = list(deployments)[0]
+
+    # Assert
+    assert (
+        gateway_deployment["spec"]
+        .get("template")
+        .get("spec")
+        .get("affinity")
+        .get("podAntiAffinity")
+        .get("requiredDuringSchedulingIgnoredDuringExecution")[0]
+        .get("labelSelector")
+        .get("matchExpressions")[0]
+        == expected_label_selector
+    )
+
+
 def test_manifests_applied_with_replicas_config(configured_harness, mocked_client):
     """
     Asserts that the Deployment manifest called by `lightkube_client.apply`
diff --git a/tests/test_bundle.py b/tests/test_bundle.py
index 06adbe0d..22ec067a 100644
--- a/tests/test_bundle.py
+++ b/tests/test_bundle.py
@@ -48,10 +48,6 @@
     plural="virtualservices",
 )
 
-EXPECTED_LABEL_SELECTOR = (
-    "LabelSelectorRequirement(key='app', operator='In', values=['istio-ingressgateway'])"
-)
-
 
 @pytest.mark.abort_on_fail
 async def test_kubectl_access(ops_test: OpsTest):
@@ -339,9 +335,8 @@ async def test_disable_ingress_auth(ops_test: OpsTest):
 
 
 async def test_gateway_replicas_config(ops_test: OpsTest):
-    """Test changing the replicas config to 2, and then:
-    1. Assert the Deployment has the antiaffinity rule as expected.
-    2. Assert the new Pod was not scheduled due to only 1 Node being available.
+    """Test changing the replicas config to 2, and Assert the new Pod was not scheduled
+    due to only 1 Node being available.
     """
 
     replicas_value = "2"
@@ -352,23 +347,6 @@ async def test_gateway_replicas_config(ops_test: OpsTest):
 
     client = lightkube.Client()
 
-    # Get the gateway Deployment
-    gateway_deployment = client.get(
-        Deployment, name="istio-ingressgateway-workload", namespace=ops_test.model_name
-    )
-
-    # Assert the Deployment has the correct antiaffinity rule
-    assert (
-        str(
-            gateway_deployment.spec.template.spec.affinity.podAntiAffinity.requiredDuringSchedulingIgnoredDuringExecution[  # noqa E501
-                0
-            ].labelSelector.matchExpressions[
-                0
-            ]
-        )
-        == EXPECTED_LABEL_SELECTOR
-    )
-
     # List gateway pods that are in Pending status
     pending_gateway_pods = list(
         client.list(

From ea2a30f4fb9ce63e8202c68a4f953b60c1a00fb0 Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Mon, 30 Sep 2024 19:35:23 +0000
Subject: [PATCH 09/10] skip: lint

---
 tests/test_bundle.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/test_bundle.py b/tests/test_bundle.py
index 22ec067a..5dacba34 100644
--- a/tests/test_bundle.py
+++ b/tests/test_bundle.py
@@ -15,7 +15,6 @@
     create_namespaced_resource,
     load_in_cluster_generic_resources,
 )
-from lightkube.resources.apps_v1 import Deployment
 from lightkube.resources.core_v1 import Pod
 from pytest_operator.plugin import OpsTest
 

From 6cc2ca0a46f8af13c5c36eb4760c210feed8ef69 Mon Sep 17 00:00:00 2001
From: NohaIhab <noha.ihab@canonical.com>
Date: Mon, 30 Sep 2024 20:33:49 +0000
Subject: [PATCH 10/10] skip: rename test and add comment

---
 charms/istio-gateway/tests/unit/test_charm.py | 2 +-
 tests/test_bundle.py                          | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/charms/istio-gateway/tests/unit/test_charm.py b/charms/istio-gateway/tests/unit/test_charm.py
index e1806b1a..9d1cac8f 100644
--- a/charms/istio-gateway/tests/unit/test_charm.py
+++ b/charms/istio-gateway/tests/unit/test_charm.py
@@ -189,7 +189,7 @@ def test_manifests_applied_with_anti_affinity(configured_harness, kind, mocked_c
     # The gateway deployment is the only Deployment object in the manifests
     gateway_deployment = list(deployments)[0]
 
-    # Assert
+    # Assert the Deployment has the correct antiaffinity rule
     assert (
         gateway_deployment["spec"]
         .get("template")
diff --git a/tests/test_bundle.py b/tests/test_bundle.py
index 5dacba34..e26d550f 100644
--- a/tests/test_bundle.py
+++ b/tests/test_bundle.py
@@ -333,7 +333,7 @@ async def test_disable_ingress_auth(ops_test: OpsTest):
     )
 
 
-async def test_gateway_replicas_config(ops_test: OpsTest):
+async def test_gateway_replicas_config_pod_anti_affinity(ops_test: OpsTest):
     """Test changing the replicas config to 2, and Assert the new Pod was not scheduled
     due to only 1 Node being available.
     """