Helm: Allow topologySpreadConstraints (#11086)

**What this PR does / why we need it**:
Allow topologySpreadConstraints for read, write, backend and gateway
statefulsets/deployments.

**Which issue(s) this PR fixes**:
Fixes #11081 

**Special notes for your reviewer**:

**Checklist**
- [x] Reviewed the
[`CONTRIBUTING.md`](https://github.com/grafana/loki/blob/main/CONTRIBUTING.md)
guide (**required**)
- [x] Documentation added
- [ ] Tests updated
- [x] `CHANGELOG.md` updated
- [ ] If the change is worth mentioning in the release notes, add
`add-to-release-notes` label
- [ ] Changes that require user attention or interaction to upgrade are
documented in `docs/sources/setup/upgrade/_index.md`
- [x] For Helm chart changes bump the Helm chart version in
`production/helm/loki/Chart.yaml` and update
`production/helm/loki/CHANGELOG.md` and
`production/helm/loki/README.md`. [Example
PR](d10549e)
- [x] If the change is deprecating or removing a configuration option,
update the `deprecated-config.yaml` and `deleted-config.yaml` files
respectively in the `tools/deprecated-config-checker` directory.
[Example
PR](0d4416a)

---------

Co-authored-by: Michel Hollands <42814411+MichelHollands@users.noreply.github.com>

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 ##### Enhancements
 
+* [11086](https://github.com/grafana/loki/pull/11086) **kandrew5**: Helm: Allow topologySpreadConstraints
 * [11003](https://github.com/grafana/loki/pull/11003) **MichelHollands**: Add the `metrics-namespace` flag to change the namespace of metrics currently using cortex as namespace.
 * [10096](https://github.com/grafana/loki/pull/10096) **aschleck**: Storage: Allow setting a constant prefix for all created keys
 * [11038](https://github.com/grafana/loki/pull/11038) **kavirajk**: Remove already deprecated `store.max-look-back-period`.

docs/sources/setup/install/helm/reference.md

@@ -366,6 +366,15 @@ null
 			<td><pre lang="json">
 []
 </pre>
+</td>
+		</tr>
+		<tr>
+			<td>backend.topologySpreadConstraints</td>
+			<td>list</td>
+			<td>Topology Spread Constraints for backend pods</td>
+			<td><pre lang="json">
+[]
+</pre>
 </td>
 		</tr>
 		<tr>
@@ -1445,6 +1454,15 @@ null
 			<td><pre lang="json">
 []
 </pre>
+</td>
+		</tr>
+		<tr>
+			<td>gateway.topologySpreadConstraints</td>
+			<td>list</td>
+			<td>Topology Spread Constraints for gateway pods</td>
+			<td><pre lang="json">
+[]
+</pre>
 </td>
 		</tr>
 		<tr>
@@ -3448,6 +3466,15 @@ null
 			<td><pre lang="json">
 []
 </pre>
+</td>
+		</tr>
+		<tr>
+			<td>read.topologySpreadConstraints</td>
+			<td>list</td>
+			<td>Topology Spread Constraints for read pods</td>
+			<td><pre lang="json">
+[]
+</pre>
 </td>
 		</tr>
 		<tr>
@@ -4748,6 +4775,15 @@ null
 			<td><pre lang="json">
 []
 </pre>
+</td>
+		</tr>
+		<tr>
+			<td>write.topologySpreadConstraints</td>
+			<td>list</td>
+			<td>Topology Spread Constraints for write pods</td>
+			<td><pre lang="json">
+[]
+</pre>
 </td>
 		</tr>
 	</tbody>

production/helm/loki/CHANGELOG.md

@@ -13,6 +13,11 @@ Entries should include a reference to the pull request that introduced the chang
 
 [//]: # (<AUTOMATED_UPDATES_LOCATOR> : do not remove this line. This locator is used by the CI pipeline to automatically create a changelog entry for each new Loki release. Add other chart versions and respective changelog entries bellow this line.)
 
+## 5.36.1
+
+- [FEATURE] Allow topology spread constraints for Loki
+
+
 ## 5.36.0
 
 - [CHANGE] Changed version of Loki to 2.9.2

production/helm/loki/Chart.yaml

@@ -3,7 +3,7 @@ name: loki
 description: Helm chart for Grafana Loki in simple, scalable mode
 type: application
 appVersion: 2.9.2
-version: 5.36.0
+version: 5.36.1
 home: https://grafana.github.io/helm-charts
 sources:
   - https://github.com/grafana/loki

production/helm/loki/README.md

@@ -1,6 +1,6 @@
 # loki
 
-![Version: 5.36.0](https://img.shields.io/badge/Version-5.36.0-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 2.9.2](https://img.shields.io/badge/AppVersion-2.9.2-informational?style=flat-square)
+![Version: 5.36.1](https://img.shields.io/badge/Version-5.36.1-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 2.9.2](https://img.shields.io/badge/AppVersion-2.9.2-informational?style=flat-square)
 
 Helm chart for Grafana Loki in simple, scalable mode
 

production/helm/loki/templates/backend/statefulset-backend.yaml

@@ -215,6 +215,10 @@ spec:
       nodeSelector:
         {{- toYaml . | nindent 8 }}
       {{- end }}
+      {{- with .Values.backend.topologySpreadConstraints }}
+      topologySpreadConstraints:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
       {{- with .Values.backend.tolerations }}
       tolerations:
         {{- toYaml . | nindent 8 }}

production/helm/loki/templates/gateway/deployment-gateway.yaml

@@ -108,6 +108,10 @@ spec:
       nodeSelector:
         {{- toYaml . | nindent 8 }}
       {{- end }}
+      {{- with .Values.gateway.topologySpreadConstraints }}
+      topologySpreadConstraints:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
       {{- with .Values.gateway.tolerations }}
       tolerations:
         {{- toYaml . | nindent 8 }}

production/helm/loki/templates/read/statefulset-read.yaml

@@ -131,6 +131,10 @@ spec:
       nodeSelector:
         {{- toYaml . | nindent 8 }}
       {{- end }}
+      {{- with .Values.read.topologySpreadConstraints }}
+      topologySpreadConstraints:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
       {{- with .Values.read.tolerations }}
       tolerations:
         {{- toYaml . | nindent 8 }}

production/helm/loki/templates/write/statefulset-write.yaml

@@ -150,6 +150,10 @@ spec:
       nodeSelector:
         {{- toYaml . | nindent 8 }}
       {{- end }}
+      {{- with .Values.write.topologySpreadConstraints }}
+      topologySpreadConstraints:
+        {{- toYaml . | nindent 8 }}
+      {{- end }}
       {{- with .Values.write.tolerations }}
       tolerations:
         {{- toYaml . | nindent 8 }}

production/helm/loki/values.yaml

@@ -800,6 +800,8 @@ write:
   dnsConfig: {}
   # -- Node selector for write pods
   nodeSelector: {}
+  # -- Topology Spread Constraints for write pods
+  topologySpreadConstraints: []
   # -- Tolerations for write pods
   tolerations: []
   # -- The default is to deploy all pods in parallel.
@@ -976,6 +978,8 @@ read:
   dnsConfig: {}
   # -- Node selector for read pods
   nodeSelector: {}
+  # -- Topology Spread Constraints for read pods
+  topologySpreadConstraints: []
   # -- Tolerations for read pods
   tolerations: []
   # -- The default is to deploy all pods in parallel.
@@ -1077,6 +1081,8 @@ backend:
   dnsConfig: {}
   # -- Node selector for backend pods
   nodeSelector: {}
+  # -- Topology Spread Constraints for backend pods
+  topologySpreadConstraints: []
   # -- Tolerations for backend pods
   tolerations: []
   # -- The default is to deploy all pods in parallel.
@@ -1333,6 +1339,8 @@ gateway:
   dnsConfig: {}
   # -- Node selector for gateway pods
   nodeSelector: {}
+  # -- Topology Spread Constraints for gateway pods
+  topologySpreadConstraints: []
   # -- Tolerations for gateway pods
   tolerations: []
   # Gateway service configuration