[receiver/k8scluster] Unify predefined and custom node metrics (open-…

…telemetry#24776)

Update node metrics description and units to be consistent and remove
predefined metrics definitions from metadata.yaml because they are
controlled by `node_conditions_to_report` and
`allocatable_types_to_report` config options. Having two controls to
enable/disable metrics would be confusing. Currently, most of the
predefined metrics are marked as enabled, but in reality only
`k8s.node.condition_ready` is reported by default.

Potentially, later we could introduce support of metadata.yaml
definitions for metrics matching particular globs like
`k8s.node.condition_*` or move the variable path of the metric name to
an attribute

.chloggen/k8scluster-remove-node-metrics-from-metadata.yaml

@@ -0,0 +1,23 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: receiver/k8scluster
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Unify predefined and custom node metrics.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [24776]
+
+# (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: |
+  - Update metrics description and units to be consistent
+  - Remove predefined metrics definitions from metadata.yaml because they are controlled by `node_conditions_to_report` 
+    and `allocatable_types_to_report` config options.

receiver/k8sclusterreceiver/documentation.md

@@ -228,86 +228,6 @@ The current phase of namespaces (1 for active and 0 for terminating)
 | ---- | ----------- | ---------- |
 | 1 | Gauge | Int |
 
-### k8s.node.allocatable_cpu
-
-How many CPU cores remaining that the node can allocate to pods
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| {cores} | Gauge | Double |
-
-### k8s.node.allocatable_ephemeral_storage
-
-How many bytes of ephemeral storage remaining that the node can allocate to pods
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| By | Gauge | Int |
-
-### k8s.node.allocatable_memory
-
-How many bytes of RAM memory remaining that the node can allocate to pods
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| By | Gauge | Int |
-
-### k8s.node.allocatable_pods
-
-How many pods remaining the node can allocate
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| {pods} | Gauge | Int |
-
-### k8s.node.allocatable_storage
-
-How many bytes of storage remaining that the node can allocate to pods
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| By | Gauge | Int |
-
-### k8s.node.condition_disk_pressure
-
-Whether this node is DiskPressure (1), not DiskPressure (0) or in an unknown state (-1)
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| 1 | Gauge | Int |
-
-### k8s.node.condition_memory_pressure
-
-Whether this node is MemoryPressure (1), not MemoryPressure (0) or in an unknown state (-1)
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| 1 | Gauge | Int |
-
-### k8s.node.condition_network_unavailable
-
-Whether this node is NetworkUnavailable (1), not NetworkUnavailable (0) or in an unknown state (-1)
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| 1 | Gauge | Int |
-
-### k8s.node.condition_pid_pressure
-
-Whether this node is PidPressure (1), not PidPressure (0) or in an unknown state (-1)
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| 1 | Gauge | Int |
-
-### k8s.node.condition_ready
-
-Whether this node is Ready (1), not Ready (0) or in an unknown state (-1)
-
-| Unit | Metric Type | Value Type |
-| ---- | ----------- | ---------- |
-| 1 | Gauge | Int |
-
 ### k8s.pod.phase
 
 Current phase of the pod (1 - Pending, 2 - Running, 3 - Succeeded, 4 - Failed, 5 - Unknown)