Add k8s.container.restart.count metric (#2191)

Signed-off-by: ChrsMark <chrismarkou92@gmail.com>

.chloggen/add_c_restarts.yaml

@@ -0,0 +1,22 @@
+# Use this changelog template to create an entry for release notes.
+#
+# If your change doesn't affect end users 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: enhancement
+
+# The name of the area of concern in the attributes-registry, (e.g. http, cloud, db)
+component: k8s
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add k8s.container.restart.count metric
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+# The values here must be integers.
+issues: [2191]
+
+# (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:

docs/non-normative/k8s-migration.md

@@ -287,9 +287,11 @@ The changes are the following:
 
 The K8s Container metrics implemented by the Collector and specifically the
 [k8scluster](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/v0.115.0/receiver/k8sclusterreceiver/documentation.md)
-receiver were introduced as semantic conventions in
+receiver were introduced as semantic conventions in:
-[#2178](https://github.com/open-telemetry/semantic-conventions/pull/2178) (TODO: replace with SemConv version once
+
-available).
+- [#2178](https://github.com/open-telemetry/semantic-conventions/pull/2178) (TODO: replace with SemConv version once
+available)
+- [#2074](https://github.com/open-telemetry/semantic-conventions/issues/2074)
 
 The changes in their metrics are the following:
 
@@ -305,5 +307,6 @@ The changes in their metrics are the following:
 | `k8s.container.storage_request`                                                    | `k8s.container.storage.request`           |
 | `k8s.container.ephemeralstorage_limit`                                                       | `k8s.container.ephemeral_storage.limit`   |
 | `k8s.container.ephemeralstorage_request`                                                     | `k8s.container.ephemeral_storage.request` |
+| `k8s.container.restarts`                  (type: `gauge`)                          | `k8s.container.restart.count` (type: `updowncounter`) |
 
 <!-- prettier-ignore-end -->

docs/system/k8s-metrics.md

@@ -74,6 +74,7 @@ and therefore inherit its attributes, like `k8s.pod.name` and `k8s.pod.uid`.
   - [Metric: `k8s.container.storage.request`](#metric-k8scontainerstoragerequest)
   - [Metric: `k8s.container.ephemeral_storage.limit`](#metric-k8scontainerephemeral_storagelimit)
   - [Metric: `k8s.container.ephemeral_storage.request`](#metric-k8scontainerephemeral_storagerequest)
+  - [Metric: `k8s.container.restart.count`](#metric-k8scontainerrestartcount)
 
 <!-- tocstop -->
 
@@ -1278,5 +1279,31 @@ This metric is [recommended][MetricRecommended].
 <!-- END AUTOGENERATED TEXT -->
 <!-- endsemconv -->
 
+### Metric: `k8s.container.restart.count`
+
+This metric is [recommended][MetricRecommended].
+
+<!-- semconv metric.k8s.container.restart.count -->
+<!-- NOTE: THIS TEXT IS AUTOGENERATED. DO NOT EDIT BY HAND. -->
+<!-- see templates/registry/markdown/snippet.md.j2 -->
+<!-- prettier-ignore-start -->
+<!-- markdownlint-capture -->
+<!-- markdownlint-disable -->
+
+| Name     | Instrument Type | Unit (UCUM) | Description    | Stability | Entity Associations |
+| -------- | --------------- | ----------- | -------------- | --------- | ------ |
+| `k8s.container.restart.count` | UpDownCounter | `{restart}` | Describes how many times the container has restarted (since the last counter reset) [1] | ![Development](https://img.shields.io/badge/-development-blue) | `k8s.container` |
+
+**[1]:** This value is pulled directly from the K8s API and the value can go indefinitely high and be reset to 0
+at any time depending on how your kubelet is configured to prune dead containers.
+It is best to not depend too much on the exact value but rather look at it as
+either == 0, in which case you can conclude there were no restarts in the recent past, or > 0, in which case
+you can conclude there were restarts in the recent past, and not try and analyze the value beyond that.
+
+<!-- markdownlint-restore -->
+<!-- prettier-ignore-end -->
+<!-- END AUTOGENERATED TEXT -->
+<!-- endsemconv -->
+
 [DocumentStatus]: https://opentelemetry.io/docs/specs/otel/document-status
 [MetricRecommended]: /docs/general/metric-requirement-level.md#recommended

model/k8s/metrics.yaml

@@ -559,3 +559,18 @@ groups:
       See https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.30/#resourcerequirements-v1-core for details.
     instrument: gauge
     unit: "By"
+  - id: metric.k8s.container.restart.count
+    type: metric
+    metric_name: k8s.container.restart.count
+    stability: development
+    brief: "Describes how many times the container has restarted (since the last counter reset)"
+    instrument: updowncounter
+    unit: "{restart}"
+    entity_associations:
+      - k8s.container
+    note: |
+      This value is pulled directly from the K8s API and the value can go indefinitely high and be reset to 0
+      at any time depending on how your kubelet is configured to prune dead containers.
+      It is best to not depend too much on the exact value but rather look at it as
+      either == 0, in which case you can conclude there were no restarts in the recent past, or > 0, in which case
+      you can conclude there were restarts in the recent past, and not try and analyze the value beyond that.