test: Add OTel engine via helm chart example in kind (#5474)

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### Brief description of Pull Request

Adds the ability to deploy OpenTelemetry Collector helm chart using
Alloy OTel Engine in `example/kind` local k8s cluster.

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### PR Checklist

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- [x] Documentation added
- [x] Tests updated
- [ ] Config converters updated

Author: thampiotr

example/kind/README.md

@@ -7,8 +7,26 @@
 - `kubectl`
 - `helm`
 
+## Usage
+
+The main command to get started with is:
+
+```bash
+task help   # list all available tasks
+```
+
+Among other things, you can create a kind cluster, deploy the local Grafana Alloy helm chart, and open k9s with the local kind cluster.
+
+```bash
+task cluster:create                       # create a kind cluster
+task deploy:alloy-helm                    # deploy the local Grafana Alloy helm chart
+k9s --kubeconfig ./build/kubeconfig.yaml  # open k9s with the local kind cluster
+```
+
 ## Setup credentials
 
+This is required if you want to deploy the Grafana Cloud Onboarding helm chart or other features that connect to Grafana Cloud.
+
 Create a local `.env.credentials` from the provided template and fill in your values. This file is gitignored and is automatically loaded by Task via `dotenv` in `Taskfile.yml`.
 
 ```bash

example/kind/Taskfile.yml

@@ -62,6 +62,20 @@ tasks:
         --set "grafanaCloud.fleetManagement.url={{.REMOTE_CFG_URL}}"
         --wait
 
+  deploy:otelcol:
+    desc: Deploy OpenTelemetry Collector helm chart using Alloy OTel Engine
+    deps: [cluster:create, update-helm-repos]
+    vars:
+      OTELCOL_VALUES_FILE: '{{.OTELCOL_VALUES_FILE | default "config/otelcol-helm/values.yaml"}}'
+    preconditions:
+      - test -f {{.OTELCOL_VALUES_FILE}}
+    cmds:
+      - helm --kubeconfig {{.KUBECONFIG}} upgrade --install otelcol
+        -n monitoring --create-namespace
+        open-telemetry/opentelemetry-collector
+        -f {{.OTELCOL_VALUES_FILE}}
+        --wait
+
   remove:cloud-onboarding:local:
     desc: Remove Grafana Cloud Onboarding helm chart
     deps: [update-helm-repos]

example/kind/config/otelcol-helm/values.yaml

@@ -0,0 +1,8 @@
+image:
+  repository: grafana/alloy-dev
+  tag: v1.13.2-devel-5bf4dcf # TODO: update to v1.14 once it's released
+
+command:
+  name: "bin/otelcol"
+
+mode: deployment