[receiver/vcenter] Adds vCenter VSAN Host metrics (#34063)

**Description:** <Describe what has changed.>
<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
The following PR adds VSAN host metric collection. The following metrics
are collected
```
vcenter.host.vsan.throughput          (direction={read/write})
vcenter.host.vsan.iops                (direction={read/write})
vcenter.host.vsan.congestions
vcenter.host.vsan.cache.hit_rate
vcenter.host.vsan.latency.avg         (direction={read/write})
```

**Link to tracking Issue:** #33556

**Testing:** <Describe what testing was performed and which tests were
added.>
Added mock data fields in order to test vsan host metric scraping.
Updated golden test file output.

**Documentation:** <Describe the documentation added.>
Updated documentation using `make generate`

Co-authored-by: Stefan Kurek <[email protected]>

Author: BominRahmani

.chloggen/add-vcenter-vsan-host-metrics.yaml

@@ -0,0 +1,33 @@
+# 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 vCenter vSAN host metrics."
+
+# 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: |
+  Introduces the following vSAN host metrics to the vCenter receiver:
+    - vcenter.host.vsan.throughput
+    - vcenter.host.vsan.iops
+    - vcenter.host.vsan.congestions
+    - vcenter.host.vsan.cache.hit_rate
+    - vcenter.host.vsan.latency.avg
+
+# 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: [user]

receiver/vcenterreceiver/client.go

@@ -177,6 +177,7 @@ func (vc *vcenterClient) HostSystems(ctx context.Context, containerMoRef vt.Mana
 		"summary.hardware.memorySize",
 		"summary.hardware.numCpuCores",
 		"summary.hardware.cpuMhz",
+		"config.vsanHostConfig.clusterInfo.nodeUuid",
 		"summary.quickStats.overallMemoryUsage",
 		"summary.quickStats.overallCpuUsage",
 		"summary.overallStatus",
@@ -366,12 +367,18 @@ type VSANMetricDetails struct {
 type vSANQueryType string
 
 const (
+	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 VSANQueryTypeHosts:
+		return []string{
+			"iopsRead", "iopsWrite", "throughputRead", "throughputWrite",
+			"latencyAvgRead", "latencyAvgWrite", "congestion", "clientCacheHitRate",
+		}
 	case VSANQueryTypeVirtualMachines:
 		return []string{
 			"iopsRead", "iopsWrite", "throughputRead", "throughputWrite",
@@ -382,7 +389,17 @@ func (vc *vcenterClient) getLabelsForQueryType(queryType vSANQueryType) []string
 	}
 }
 
-// VSANVirtualMachines returns back virtual machine vSAN performance metrics
+// VSANHosts returns host VSAN performance metrics for a group of clusters
+func (vc *vcenterClient) VSANHosts(
+	ctx context.Context,
+	clusterRefs []*vt.ManagedObjectReference,
+) (*VSANQueryResults, error) {
+	results, err := vc.vSANQuery(ctx, VSANQueryTypeHosts, clusterRefs)
+	err = vc.handleVSANError(err, VSANQueryTypeHosts)
+	return results, err
+}
+
+// VSANVirtualMachines returns virtual machine vSAN performance metrics for a group of clusters
 func (vc *vcenterClient) VSANVirtualMachines(
 	ctx context.Context,
 	clusterRefs []*vt.ManagedObjectReference,

receiver/vcenterreceiver/documentation.md

@@ -652,6 +652,74 @@ metrics:
     enabled: true
 ```
 
+### vcenter.host.vsan.cache.hit_rate
+
+The host's read IOs which could be satisfied by the local client cache.
+
+As measured over the most recent 5m interval.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| % | Gauge | Int |
+
+### vcenter.host.vsan.congestions
+
+The congestions of IOs generated by all vSAN clients in the host.
+
+As measured over the most recent 5m interval.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {congestions/sec} | Gauge | Double |
+
+### vcenter.host.vsan.latency.avg
+
+The host latency while accessing vSAN storage.
+
+As measured over the most recent 5m interval.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| us | Gauge | Int |
+
+#### Attributes
+
+| Name | Description | Values |
+| ---- | ----------- | ------ |
+| type | The type of vSAN latency. | Str: ``read``, ``write`` |
+
+### vcenter.host.vsan.operations
+
+The vSAN IOPs of a host.
+
+As measured over the most recent 5m interval.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| {operations/sec} | Gauge | Int |
+
+#### Attributes
+
+| Name | Description | Values |
+| ---- | ----------- | ------ |
+| type | The type of vSAN operation. | Str: ``read``, ``write``, ``unmap`` |
+
+### vcenter.host.vsan.throughput
+
+The vSAN throughput of a host.
+
+As measured over the most recent 5m interval.
+
+| Unit | Metric Type | Value Type |
+| ---- | ----------- | ---------- |
+| By/s | Gauge | Double |
+
+#### Attributes
+
+| Name | Description | Values |
+| ---- | ----------- | ------ |
+| direction | The type of vSAN throughput. | Str: ``read``, ``write`` |
+
 ### vcenter.vm.vsan.latency.avg
 
 The virtual machine latency while accessing vSAN storage.