Document list of configuration opportunities in Helm Chart docs (#564)

* Document list of configuration opportunities in Helm Chart docs

* Provide requirements & insights that it deploys service

* Trigger CI on chart changes

* Formatting tweak

.azure-devops/scraper-ci.yml

@@ -11,6 +11,7 @@ pr:
     include:
     - src/*
     - .azure-devops/scraper-ci.yml
+    - charts/promitor-agent-scraper/*
 variables:
   DotNet.SDK.Version: '2.2.203'
   Image.Name: 'tomkerkhove/promitor-agent-scraper-ci'

charts/promitor-agent-scraper/README.md

@@ -11,11 +11,12 @@ $ helm install promitor/promitor-agent-scraper
 
 ## Introduction
 
-This chart bootstraps a **Promitor Scraper Agent** deployment on a Kubernetes cluster using the Helm package manager.
+This chart bootstraps a **Promitor Scraper Agent** deployment on a Kubernetes cluster using the Helm package manager. It will provide the scraper agent with a Kubernetes Service so that other Pods can consume it.
 
 ## Prerequisites
 
-None.
+- Azure Subscription
+- Azure AD Application to authenticate with ([docs](https://promitor.io/configuration/#authentication-with-azure-monitor))
 
 ## Installing the Chart
 
@@ -38,4 +39,48 @@ To uninstall/delete the `promitor-agent-scraper` deployment:
 $ helm delete promitor-agent-scraper
 ```
 
-The command removes all the Kubernetes components associated with the chart and deletes the release.
+The command removes all the Kubernetes components associated with the chart and deletes the release.
+
+## Configuration
+
+The following table lists the configurable parameters of the Promitor chart and their default values.
+
+| Parameter                  | Description              | Default              |
+|:---------------------------|:-------------------------|:---------------------|
+| `image.repository`  | Repository which provides the image | `tomkerkhove/promitor-agent-scraper` |
+| `image.tag`  | Tag of image to use | `1.0.0-preview-6`            |
+| `image.pullPolicy`  | Policy to pull image | `Always`            |
+| `azureAuthentication.appId`  | Id of the Azure AD entity to authenticate with |             |
+| `azureAuthentication.appKey`  | Secret of the Azure AD entity to authenticate with |             |
+| `scrapeConfig.path`  | Path where the scraping endpoint for Prometheus is being exposed | `/metrics`            |
+| `scrapeConfig.timestamp`  | Indication wheter or not to include timestamp | `true`            |
+| `telemetry.appInsightsKey`  | Application Insights telemetry key |             |
+| `logging.minimalLogLevel`  | Minimum level of logging | `Warning`            |
+| `azureMetadata.tenantId`  | Id of Azure tenant |             |
+| `azureMetadata.subscriptionId`  | Id of Azure subscription |             |
+| `azureMetadata.resourceGroupName`  | Name of resource group | `promitor`            |
+| `metricDefaults.aggregation.interval`  | Default interval which defines over what period measurements of a metric should be aggregated | `00:05:00`            |
+| `metricDefaults.scraping.schedule`  | Cron expression that controls the fequency in which all the configured metrics will be scraped from Azure Monitor | `*/5 * * * *`            |
+| `metrics`  | List of metrics to scrape configured following the [metric declaration docs](https://promitor.io/configuration/metrics/) |        |
+| `secrets.createSecret`  | Indication if you want to bring your own secret level of logging | `true`            |
+| `secrets.appIdSecret`  | Name of the secret for Azure AD identity id | `azure-app-id`            |
+| `secrets.appKeySecret`  | Name of the secret for Azure AD identity secret | `azure-app-key`            |
+| `secrets.appInsightsSecret`  | Name of the secret for Application Insights instrumentation key | `azure-appinsights-key`            |
+| `service.exposeExternally`  | Indication wheter or not to expose service externally | `false`            |
+| `service.port`  | Port on service for other pods to talk to | `80`            |
+| `service.targetPort`  | Port on container to serve traffic | `9090`            |
+| `service.labelType`  | Label to assign to your service | `infrastructure`            |
+| `service.selectorType`  | Selector type to use for the service | `runtime`            |
+
+Specify each parameter using the `--set key=value[,key=value]` argument to `helm install`. For example,
+
+```console
+$ helm install promitor/promitor-agent-scraper --name promitor-agent-scraper \
+    --set logging.minimalLogLevel=Trace
+```
+
+Alternatively, a YAML file that specifies the values for the above parameters can be provided while installing the chart. For example,
+
+```console
+$ helm install promitor/promitor-agent-scraper --name promitor-agent-scraper -f values.yaml
+```