Add loki.memberlistConfig to fully control the memberlist configuration (#9646)

**What this PR does / why we need it**:

Add loki.memberlistConfig to fully control the memberlist configuration

On singleBinary with replica 1, memberlist isn't need and its
counter-productive since it delays the start of the loki binary. At the
moment, it isn't possible to remove the memberlist defaults.

**Which issue(s) this PR fixes**:
Fixes #<issue number>

**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
- [ ] Changes that require user attention or interaction to upgrade are
documented in `docs/sources/upgrading/_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](d10549e3ec)

docs/sources/installation/helm/reference.md

@@ -1827,7 +1827,7 @@ true
 		<tr>
 			<td>loki.extraMemberlistConfig</td>
 			<td>object</td>
-			<td></td>
+			<td>Extra memberlist configuration</td>
 			<td><pre lang="json">
 {}
 </pre>
@@ -1929,6 +1929,15 @@ null
   "split_queries_by_interval": "15m"
 }
 </pre>
+</td>
+		</tr>
+		<tr>
+			<td>loki.memberlistConfig</td>
+			<td>object</td>
+			<td>memberlist configuration (overrides embedded default)</td>
+			<td><pre lang="json">
+{}
+</pre>
 </td>
 		</tr>
 		<tr>

production/helm/loki/CHANGELOG.md

@@ -13,6 +13,10 @@ 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.)
 
+## 5.8.0
+
+- [ENHANCEMENT] Add loki.memberlistConfig to fully control the memberlist configuration
+
 ## 5.7.1
 
 - [FEATURE] Add support for additional labels on loki-canary pods

production/helm/loki/Chart.yaml

@@ -3,7 +3,7 @@ name: loki
 description: Helm chart for Grafana Loki in simple, scalable mode
 type: application
 appVersion: 2.8.2
-version: 5.7.1
+version: 5.8.0
 home: https://grafana.github.io/helm-charts
 sources:
   - https://github.com/grafana/loki

production/helm/loki/README.md

@@ -1,6 +1,6 @@
 # loki
 
-![Version: 5.7.1](https://img.shields.io/badge/Version-5.7.1-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 2.8.2](https://img.shields.io/badge/AppVersion-2.8.2-informational?style=flat-square)
+![Version: 5.8.0](https://img.shields.io/badge/Version-5.8.0-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 2.8.2](https://img.shields.io/badge/AppVersion-2.8.2-informational?style=flat-square)
 
 Helm chart for Grafana Loki in simple, scalable mode
 

production/helm/loki/values.yaml

@@ -96,6 +96,9 @@ loki:
     {{- end}}
 
     memberlist:
+    {{- if .Values.loki.memberlistConfig }}
+      {{- toYaml .Values.loki.memberlistConfig | nindent 2 }}
+    {{- else }}
     {{- if .Values.loki.extraMemberlistConfig}}
     {{- toYaml .Values.loki.extraMemberlistConfig | nindent 2}}
     {{- end }}
@@ -106,6 +109,7 @@ loki:
         - {{ .memberlistService }}
         {{- end }}
         {{- end }}
+    {{- end }}
 
     {{- with .Values.loki.ingester }}
     ingester:
@@ -145,7 +149,7 @@ loki:
     {{- end }}
     {{- end }}
 
-    {{- if .Values.loki.schemaConfig}}
+    {{- if .Values.loki.schemaConfig }}
     schema_config:
     {{- toYaml .Values.loki.schemaConfig | nindent 2}}
     {{- else }}
@@ -227,7 +231,9 @@ loki:
     {{- end }}
   # Should authentication be enabled
   auth_enabled: true
-  #  Extra memberlist configuration
+  # -- memberlist configuration (overrides embedded default)
+  memberlistConfig: {}
+  # -- Extra memberlist configuration
   extraMemberlistConfig: {}
   # -- Tenants list to be created on nginx htpasswd file, with name and password keys
   tenants: []