From 724821b265f370032110c6e1b46a33a995adc452 Mon Sep 17 00:00:00 2001
From: Andrey Tatarinov <a@tatarinov.co>
Date: Tue, 27 Aug 2024 21:14:27 +0400
Subject: [PATCH] switch to spreadServiceAcrossNodes setting

---
 charts/simple-app/CHANGELOG.md              |  4 ++++
 charts/simple-app/Chart.yaml                |  2 +-
 charts/simple-app/templates/deployment.yaml |  9 ++++++---
 charts/simple-app/tests/simple_test.yaml    | 19 +++++++++++++++++++
 charts/simple-app/values.schema.json        |  3 +++
 charts/simple-app/values.yaml               |  6 +++---
 6 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/charts/simple-app/CHANGELOG.md b/charts/simple-app/CHANGELOG.md
index 3c8ab7b..c114e01 100644
--- a/charts/simple-app/CHANGELOG.md
+++ b/charts/simple-app/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 0.13.0
+
+* Add `spreadServiceAcrossNodes` setting
+
 # 0.12.0, 0.12.1
 
 * Add `monitoringCoreos` setting for prometheus-operator managed metrics
diff --git a/charts/simple-app/Chart.yaml b/charts/simple-app/Chart.yaml
index e226bc3..6737762 100644
--- a/charts/simple-app/Chart.yaml
+++ b/charts/simple-app/Chart.yaml
@@ -15,7 +15,7 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: "0.12.1"
+version: "0.13.0"
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
diff --git a/charts/simple-app/templates/deployment.yaml b/charts/simple-app/templates/deployment.yaml
index 73859ab..dcc1368 100644
--- a/charts/simple-app/templates/deployment.yaml
+++ b/charts/simple-app/templates/deployment.yaml
@@ -131,10 +131,13 @@ spec:
       tolerations:
         {{- toYaml . | nindent 8 }}
       {{- end }}
+      {{- if .Values.spreadServiceAcrossNodes }}
       topologySpreadConstraints:
       - labelSelector:
           matchLabels:
-            app.kubernetes.io/instance: {{ .Release.Name }}
-        maxSkew: {{ .Values.skew }}
+          {{- include "simple-app.selectorLabels" . | nindent 12 }}
+        maxSkew: 1
         topologyKey: "kubernetes.io/hostname"
-        whenUnsatisfiable: {{ .Values.skewPolicy }}
\ No newline at end of file
+        nodeTaintsPolicy: Honor
+        whenUnsatisfiable: ScheduleAnyway
+      {{- end }}
diff --git a/charts/simple-app/tests/simple_test.yaml b/charts/simple-app/tests/simple_test.yaml
index dec399f..7aa0be9 100644
--- a/charts/simple-app/tests/simple_test.yaml
+++ b/charts/simple-app/tests/simple_test.yaml
@@ -308,3 +308,22 @@ tests:
       - equal:
           path: metadata.name
           value: simple
+
+  - it: Spread service across nodes
+    template: deployment.yaml
+    set:
+      spreadServiceAcrossNodes: true
+    asserts:
+      - isKind:
+          of: Deployment
+      - equal:
+          path: spec.template.spec.topologySpreadConstraints
+          value:
+            - maxSkew: 1
+              topologyKey: kubernetes.io/hostname
+              nodeTaintsPolicy: Honor
+              whenUnsatisfiable: ScheduleAnyway
+              labelSelector:
+                matchLabels:
+                  app.kubernetes.io/instance: simple
+                  app.kubernetes.io/name: simple-app
diff --git a/charts/simple-app/values.schema.json b/charts/simple-app/values.schema.json
index 7d39fbf..1aae96e 100644
--- a/charts/simple-app/values.schema.json
+++ b/charts/simple-app/values.schema.json
@@ -196,6 +196,9 @@
         "affinity": {
             "type": "object"
         },
+        "spreadServiceAcrossNodes": {
+            "type": "boolean"
+        },
         "gke": {
             "type": "object",
             "properties": {
diff --git a/charts/simple-app/values.yaml b/charts/simple-app/values.yaml
index 76f996a..2f62c7c 100644
--- a/charts/simple-app/values.yaml
+++ b/charts/simple-app/values.yaml
@@ -4,9 +4,6 @@
 # This is a YAML-formatted file.
 # Declare variables to be passed into your templates.
 
-skew: 1
-skewPolicy: ScheduleAnyway
-
 nameOverride: ""
 fullnameOverride: ""
 
@@ -181,6 +178,9 @@ tolerations: []
 
 affinity: {}
 
+# If set, create topologySpreadConstraints to spread the pods across nodes
+spreadServiceAcrossNodes: false
+
 # Settings specific to GKE deployment
 gke:
   # If enabled and gateway.enabled is true, creates GCPBackendPolicy and