device-injector: add support for CDI injection.

Add support for injecting annotated CDI devices using the
new native NRI CDI injection API.

Signed-off-by: Krisztian Litkey <[email protected]>

plugins/device-injector/README.md

@@ -1,7 +1,7 @@
 ## Device Injector Plugin
 
-This sample plugin can inject devices and mounts into containers using
-pod annotations.
+This sample plugin can inject Linux device nodes, CDI devices, and mounts into
+containers using pod annotations.
 
 ### Device Annotations
 
@@ -26,6 +26,33 @@ The annotation syntax for device injection is
 
 `file_mode`, `uid` and `gid` can be omitted, the rest are mandatory.
 
+### CDI Device Annotations
+
+Devices are annotated using the `cdi-devices.nri.io` annotation key prefix.
+The key `cdi-devices.nri.io/container.$CONTAINER_NAME` annotates CDI devices
+to be injected into `$CONTAINER_NAME`. The keys `cdi-devices.nri.io` and
+`cdi-devices.nri.io/pod` annotate CDI devices to be injected into all
+containers of the pod.
+
+The annotation value syntax is an array of CDI device names to inject. For
+instance, the following annotation
+
+```
+metadata:
+  name: bash
+  annotations:
+    cdi-devices.nri.io/container.c0: |
+      - vendor0.com/device=null
+    cdi-devices.nri.io/container.c1: |
+      - vendor0.com/device=zero
+    cdi-devices.nri.io/container.mgmt: |
+      - vendor0.com/device=all
+```
+
+requests the injection of the vendor0.com/device=null, vendor0.com/device=zero,
+and vendor0.com/device=all CDI devices, to the c0, c1, and mgmt containers of
+the pod.
+
 ### Mount Annotations
 
 Mounts are annotated in a similar manner to devices, but using the

plugins/device-injector/device-injector.go

@@ -35,6 +35,8 @@ const (
 	deviceKey = "devices.nri.io"
 	// Prefix of the key used for mount annotations.
 	mountKey = "mounts.nri.io"
+	// Prefix of the key used for CDI device annotations.
+	cdiDeviceKey = "cdi-devices.nri.io"
 )
 
 var (
@@ -69,10 +71,11 @@ type plugin struct {
 // CreateContainer handles container creation requests.
 func (p *plugin) CreateContainer(_ context.Context, pod *api.PodSandbox, container *api.Container) (*api.ContainerAdjustment, []*api.ContainerUpdate, error) {
 	var (
-		ctrName string
-		devices []device
-		mounts  []mount
-		err     error
+		ctrName    string
+		devices    []device
+		cdiDevices []string
+		mounts     []mount
+		err        error
 	)
 
 	ctrName = containerName(pod, container)
@@ -104,6 +107,31 @@ func (p *plugin) CreateContainer(_ context.Context, pod *api.PodSandbox, contain
 		}
 	}
 
+	// inject CDI devices to container
+	cdiDevices, err = parseCDIDevices(container.Name, pod.Annotations)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if len(cdiDevices) == 0 {
+		log.Infof("%s: no CDI devices annotated...", ctrName)
+	} else {
+		if verbose {
+			dump(ctrName, "annotated CDI devices", devices)
+		}
+
+		for _, name := range cdiDevices {
+			adjust.AddCDIDevice(
+				&api.CDIDevice{
+					Name: name,
+				},
+			)
+			if !verbose {
+				log.Infof("%s: injected CDI device %q...", ctrName, name)
+			}
+		}
+	}
+
 	// inject mounts to container
 	mounts, err = parseMounts(container.Name, pod.Annotations)
 	if err != nil {
@@ -162,6 +190,36 @@ func parseDevices(ctr string, annotations map[string]string) ([]device, error) {
 	return devices, nil
 }
 
+func parseCDIDevices(ctr string, annotations map[string]string) ([]string, error) {
+	var (
+		key        string
+		annotation []byte
+		cdiDevices []string
+	)
+
+	// look up effective device annotation and unmarshal devices
+	for _, key = range []string{
+		cdiDeviceKey + "/container." + ctr,
+		cdiDeviceKey + "/pod",
+		cdiDeviceKey,
+	} {
+		if value, ok := annotations[key]; ok {
+			annotation = []byte(value)
+			break
+		}
+	}
+
+	if annotation == nil {
+		return nil, nil
+	}
+
+	if err := yaml.Unmarshal(annotation, &cdiDevices); err != nil {
+		return nil, fmt.Errorf("invalid CDI device annotation %q: %w", key, err)
+	}
+
+	return cdiDevices, nil
+}
+
 func parseMounts(ctr string, annotations map[string]string) ([]mount, error) {
 	var (
 		key        string