[helm] Fix tracing configuration (#11186)

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

This PR allows user to enable tracing in the new SSD setup and fixes
incorrect documentation because it is currently impossible to enable
tracing in this chart (cf.
https://github.com/grafana/loki/blob/766f27645d2610a36eaaca8418482b740ae14215/cmd/loki/main.go#L81)

**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
- [x] Tests updated
- [ ] `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`
- [ ] 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)
- [ ] 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)

---------

Signed-off-by: QuentinBisson <quentin@giantswarm.io>

docs/sources/operations/troubleshooting.md

@@ -173,7 +173,11 @@ Jaeger is running.
 If you deploy with Helm, use the following command:
 
 ```bash
-$ helm upgrade --install loki loki/loki --set "loki.tracing.jaegerAgentHost=YOUR_JAEGER_AGENT_HOST"
+$ helm upgrade --install loki loki/loki --set "loki.tracing.enabled=true"
+  --set "read.extraEnv[0].name=JAEGER_AGENT_HOST"    --set "read.extraEnv[0].value=<JAEGER_AGENT_HOST>"
+  --set "write.extraEnv[0].name=JAEGER_AGENT_HOST"   --set "write.extraEnv[0].value=<JAEGER_AGENT_HOST>"
+  --set "backend.extraEnv[0].name=JAEGER_AGENT_HOST" --set "backend.extraEnv[0].value=<JAEGER_AGENT_HOST>"
+  --set "gateway.extraEnv[0].name=JAEGER_AGENT_HOST" --set "gateway.extraEnv[0].value=<JAEGER_AGENT_HOST>"
 ```
 
 ## Running Loki with Istio Sidecars

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

@@ -2297,6 +2297,17 @@ null
 			<td><pre lang="json">
 []
 </pre>
+</td>
+		</tr>
+		<tr>
+			<td>loki.tracing</td>
+			<td>object</td>
+			<td>Enable tracing</td>
+			<td><pre lang="json">
+{
+  "enabled": false
+}
+</pre>
 </td>
 		</tr>
 		<tr>
@@ -4393,15 +4404,6 @@ null
 			<td><pre lang="json">
 "1m"
 </pre>
-</td>
-		</tr>
-		<tr>
-			<td>tracing.jaegerAgentHost</td>
-			<td>string</td>
-			<td></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.)
 
+## 5.37.0
+
+- [FEATURE] Add support for enabling tracing.
+
 ## 5.36.2
 
 - [BUGFIX] Add support to run dnsmasq

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: 5.36.3
+version: 5.37.0
 home: https://grafana.github.io/helm-charts
 sources:
   - https://github.com/grafana/loki

production/helm/loki/README.md

@@ -1,6 +1,6 @@
 # loki
 
-![Version: 5.36.3](https://img.shields.io/badge/Version-5.36.3-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: 5.37.0](https://img.shields.io/badge/Version-5.37.0-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)
 
 Helm chart for Grafana Loki in simple, scalable mode
 

production/helm/loki/values.yaml

@@ -240,6 +240,9 @@ loki:
     distributor:
       {{- tpl (. | toYaml) $ | nindent 4 }}
     {{- end }}
+
+    tracing:
+      enabled: {{ .Values.loki.tracing.enabled }}
   # Should authentication be enabled
   auth_enabled: true
   # -- memberlist configuration (overrides embedded default)
@@ -344,6 +347,9 @@ loki:
     scheduler_address: '{{ include "loki.querySchedulerAddress" . }}'
   # -- Optional distributor configuration
   distributor: {}
+  # -- Enable tracing
+  tracing:
+    enabled: false
 enterprise:
   # Enable enterprise features, license must be provided
   enabled: false
@@ -1474,8 +1480,6 @@ networkPolicy:
     podSelector: {}
     # -- Specifies the namespace the discovery Pods are running in
     namespaceSelector: {}
-tracing:
-  jaegerAgentHost: ""
 # -------------------------------------
 # Configuration for `minio` child chart
 # -------------------------------------