[CONTINT-4898] Add container metric support for any CRI compliant runtime (#43317)

### What does this PR do?
Adds container metric support for any CRI compliant runtime provided as a `cri_socket_path`.

### Motivation
Despite allowing custom `cri_socket_path` values, we actually only allow `containerd` or `crio`. We want to support metric collection for any runtime if it is CRI compliant.

### Describe how you validated your changes
1. Stand up an environment running a nonstandard runtime (for example, pouch)
```bash
$ kubectl get nodes -o wide
NAME       STATUS   ROLES           AGE    VERSION    INTERNAL-IP     EXTERNAL-IP   OS-IMAGE             KERNEL-VERSION     CONTAINER-RUNTIME
pouch-qa   Ready    control-plane   5d2h   v1.25.16   192.168.64.50   <none>        Ubuntu 24.04.3 LTS   6.8.0-87-generic   pouch://1.3.1-ba854f2d
```

2. Deploy an agent built off of this feature branch and specify the custom socket
```yaml
datadog:
  ...
  criSocketPath: /var/run/pouchcri.sock
agents:
  ...
  volumes:
    - name: pouchcri-sock
      hostPath:
        path: /var/run/pouchcri.sock  # path on the node
        type: Socket

  volumeMounts:
    - name: pouchcri-sock
      mountPath: /var/run/pouchcri.sock
      readOnly: true
```

3. Exec onto the agent and validate that the `nonstandard-cri-runtime` feature was detected by executing `agent status`
```bash
$ agent status
...
=============
Autodiscovery
=============

  Enabled Features
  ================
    cri
    kube_orchestratorexplorer
    kubernetes
    nonstandard-cri-runtime
...
```
4. Validate that container metrics work in the UI:
<img width="1125" height="478" alt="Screenshot 2025-11-24 at 3 42 10 PM" src="https://github.com/user-attachments/assets/d6ec023b-3f67-4c32-8c81-8ca34945802f" />
<img width="1310" height="423" alt="Screenshot 2025-11-24 at 3 40 51 PM" src="https://github.com/user-attachments/assets/79a40cc5-e9ee-45e9-b498-7e062a682d0a" />


### Additional Notes


Co-authored-by: justin.lesko <[email protected]>

Author: justin-lesko

pkg/config/env/environment_container_features.go

@@ -37,4 +37,7 @@ const (
 	PodResources Feature = "podresources"
 	// NVML library present for GPU detection
 	NVML Feature = "nvml"
+	// NonstandardCRIRuntime is a fallback value for when customers supply a CRI compliant runtime via the
+	// cri_socket_path configuration field
+	NonstandardCRIRuntime = "nonstandard-cri-runtime"
 )

pkg/config/env/environment_containers.go

@@ -51,6 +51,7 @@ func init() {
 	registerFeature(Podman)
 	registerFeature(PodResources)
 	registerFeature(NVML)
+	registerFeature(NonstandardCRIRuntime)
 }
 
 // IsAnyContainerFeaturePresent checks if any of known container features is present
@@ -65,7 +66,8 @@ func IsAnyContainerFeaturePresent() bool {
 		IsFeaturePresent(ECSManagedInstances) ||
 		IsFeaturePresent(EKSFargate) ||
 		IsFeaturePresent(CloudFoundry) ||
-		IsFeaturePresent(Podman)
+		IsFeaturePresent(Podman) ||
+		IsFeaturePresent(NonstandardCRIRuntime)
 }
 
 func detectContainerFeatures(features FeatureMap, cfg model.Reader) {
@@ -144,6 +146,8 @@ func detectCriRuntimes(features FeatureMap, cfg model.Reader) {
 			mergeContainerdNamespaces(cfg)
 		} else if strings.Contains(criSocket, "crio") {
 			features[Crio] = struct{}{}
+		} else {
+			features[NonstandardCRIRuntime] = struct{}{}
 		}
 	}
 }

pkg/util/containers/metrics/cri/collector.go

@@ -58,7 +58,8 @@ func newCRICollector(cache *provider.Cache) (provider.CollectorMetadata, error)
 	return provider.CollectorMetadata{
 		ID: collectorID,
 		Collectors: provider.CollectorCatalog{
-			provider.NewRuntimeMetadata(string(provider.RuntimeNameCRIO), ""): provider.MakeCached(collectorID, cache, collectors),
+			provider.NewRuntimeMetadata(string(provider.RuntimeNameCRIO), ""):           provider.MakeCached(collectorID, cache, collectors),
+			provider.NewRuntimeMetadata(string(provider.RuntimeNameCRINonstandard), ""): provider.MakeCached(collectorID, cache, collectors),
 		},
 	}, nil
 }

pkg/util/containers/metrics/kubelet/collector.go

@@ -89,6 +89,7 @@ func newKubeletCollector(_ *provider.Cache, wmeta workloadmeta.Component) (provi
 			provider.NewRuntimeMetadata(string(provider.RuntimeNameContainerd), string(provider.RuntimeFlavorKata)): collectors,
 			provider.NewRuntimeMetadata(string(provider.RuntimeNameCRIO), ""):                                       collectors,
 			provider.NewRuntimeMetadata(string(provider.RuntimeNameDocker), ""):                                     collectors,
+			provider.NewRuntimeMetadata(string(provider.RuntimeNameCRINonstandard), ""):                             collectors,
 		},
 	}, nil
 }

pkg/util/containers/metrics/provider/provider.go

@@ -14,6 +14,8 @@ import (
 	"sync"
 
 	workloadmeta "github.com/DataDog/datadog-agent/comp/core/workloadmeta/def"
+	"github.com/DataDog/datadog-agent/pkg/config/env"
+	"github.com/DataDog/datadog-agent/pkg/util/log"
 	"github.com/DataDog/datadog-agent/pkg/util/option"
 	"github.com/DataDog/datadog-agent/pkg/util/retry"
 )
@@ -30,6 +32,7 @@ const (
 	RuntimeNamePodman              Runtime = "podman"
 	RuntimeNameECSFargate          Runtime = "ecsfargate"
 	RuntimeNameECSManagedInstances Runtime = "ecsmanagedinstances"
+	RuntimeNameCRINonstandard      Runtime = "cri-nonstandard"
 )
 
 var (
@@ -58,6 +61,7 @@ var (
 		RuntimeNamePodman,
 		RuntimeNameECSFargate,
 		RuntimeNameECSManagedInstances,
+		RuntimeNameCRINonstandard,
 	}
 
 	// AllWindowsRuntimes lists all runtimes available on Windows
@@ -67,7 +71,11 @@ var (
 		RuntimeNameContainerd,
 		RuntimeNameECSFargate,
 		RuntimeNameECSManagedInstances,
+		RuntimeNameCRINonstandard,
 	}
+
+	// nonstandardMetadata is used as a map key in GetCollector() when the NonstandardCRIRuntime feature is present
+	nonstandardMetadata = NewRuntimeMetadata(string(RuntimeNameCRINonstandard), "")
 )
 
 // RuntimeFlavor is a typed string for supported container runtime flavors
@@ -148,6 +156,17 @@ func (mp *GenericProvider) GetCollector(r RuntimeMetadata) Collector {
 		return runtime
 	}
 
+	// if the nonstandard runtime feature is present that means
+	// the user supplied a runtime socket that does not map to any of our known
+	// runtimes: containerd, cri-o
+	if env.IsFeaturePresent(env.NonstandardCRIRuntime) {
+		log.Debugf("Overriding collector runtime from %s to %s", r.String(), nonstandardMetadata.String())
+
+		if runtime, found := mp.collectors[nonstandardMetadata]; found {
+			return runtime
+		}
+	}
+
 	return nil
 }
 

releasenotes/notes/nonstandard-cri-runtime-support-1c3fdee8ea681fda.yaml

@@ -0,0 +1,12 @@
+# Each section from every release note are combined when the
+# CHANGELOG.rst is rendered. So the text needs to be worded so that
+# it does not depend on any information only available in another
+# section. This may mean repeating some details, but each section
+# must be readable independently of the other.
+#
+# Each section note must be formatted as reStructuredText.
+---
+enhancements:
+  - |
+    Add container metric support for any CRI compliant runtime specified in
+    the `cri_socket_path` configuration.