[receiver/vcenter] Adds vSAN metrics for Clusters (#34084)

**Description:** <Describe what has changed.>
Waiting on
#34082
to be merged first.
Adds a set of default disabled vSAN metrics for Clusters.

```
vcenter.cluster.vsan.throughput          (direction={read/write})
vcenter.cluster.vsan.iops                (direction={read/write})
vcenter.cluster.vsan.latency.avg         (direction={read/write})
vcenter.cluster.vsan.congestions
```

**Link to tracking Issue:** <Issue number if applicable>
#33556 

**Testing:** <Describe what testing was performed and which tests were
added.>
Unit tests added for scraper.
Could not add client tests as govmomi vSAN simulator currently not
implemented.
Test against live environment.

**Documentation:** <Describe the documentation added.>
New documentation generated

.chloggen/vcenterreceiver-cluster-vsan.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'enhancement'
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: 'vcenterreceiver'
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Adds a number of default disabled vSAN metrics for Clusters.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [33556]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

receiver/vcenterreceiver/client.go

@@ -154,6 +154,7 @@ func (vc *vcenterClient) ComputeResources(ctx context.Context, containerMoRef vt
 		"datastore",
 		"host",
 		"summary",
+		"configurationEx",
 	}, &computes)
 	if err != nil {
 		return nil, fmt.Errorf("unable to retrieve ComputeResources (& ClusterComputeResources): %w", err)
@@ -367,13 +368,19 @@ type VSANMetricDetails struct {
 type vSANQueryType string
 
 const (
+	VSANQueryTypeClusters        vSANQueryType = "cluster-domclient:*"
 	VSANQueryTypeHosts           vSANQueryType = "host-domclient:*"
 	VSANQueryTypeVirtualMachines vSANQueryType = "virtual-machine:*"
 )
 
 // getLabelsForQueryType returns the appropriate labels for each query type
 func (vc *vcenterClient) getLabelsForQueryType(queryType vSANQueryType) []string {
 	switch queryType {
+	case VSANQueryTypeClusters:
+		return []string{
+			"iopsRead", "iopsWrite", "throughputRead", "throughputWrite",
+			"latencyAvgRead", "latencyAvgWrite", "congestion",
+		}
 	case VSANQueryTypeHosts:
 		return []string{
 			"iopsRead", "iopsWrite", "throughputRead", "throughputWrite",
@@ -389,6 +396,16 @@ func (vc *vcenterClient) getLabelsForQueryType(queryType vSANQueryType) []string
 	}
 }
 
+// VSANClusters returns back cluster vSAN performance metrics
+func (vc *vcenterClient) VSANClusters(
+	ctx context.Context,
+	clusterRefs []*vt.ManagedObjectReference,
+) (*VSANQueryResults, error) {
+	results, err := vc.vSANQuery(ctx, VSANQueryTypeClusters, clusterRefs)
+	err = vc.handleVSANError(err, VSANQueryTypeClusters)
+	return results, err
+}
+
 // VSANHosts returns host VSAN performance metrics for a group of clusters
 func (vc *vcenterClient) VSANHosts(
 	ctx context.Context,

receiver/vcenterreceiver/documentation.md

@@ -652,6 +652,56 @@ metrics:
     enabled: true
 ```
 
+### vcenter.cluster.vsan.congestions
+
+The congestions of IOs generated by all vSAN clients in the cluster.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {congestions/sec} | Gauge | Double |
+
+### vcenter.cluster.vsan.latency.avg
+
+The overall cluster latency while accessing vSAN storage.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| us | Gauge | Int |
+
+#### Attributes
+
+| Name | Description | Values |
+| ---- | ----------- | ------ |
+| type | The type of vSAN latency. | Str: ``read``, ``write`` |
+
+### vcenter.cluster.vsan.operations
+
+The vSAN IOPs of a cluster.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {operations/sec} | Gauge | Int |
+
+#### Attributes
+
+| Name | Description | Values |
+| ---- | ----------- | ------ |
+| type | The type of vSAN operation. | Str: ``read``, ``write``, ``unmap`` |
+
+### vcenter.cluster.vsan.throughput
+
+The vSAN throughput of a cluster.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| By/s | Gauge | Double |
+
+#### Attributes
+
+| Name | Description | Values |
+| ---- | ----------- | ------ |
+| direction | The type of vSAN throughput. | Str: ``read``, ``write`` |
+
 ### vcenter.host.vsan.cache.hit_rate
 
 The host's read IOs which could be satisfied by the local client cache.