Add logic to filter out CDI devices based on namespace annotations

Signed-off-by: Evan Lezar <[email protected]>

cmd/plugins/cdi-device-injector/cdi-device-injector.go

@@ -19,6 +19,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"path/filepath"
 	"strings"
 
 	"github.com/sirupsen/logrus"
@@ -46,7 +47,7 @@ type plugin struct {
 }
 
 // CreateContainer handles container creation requests.
-func (p *plugin) CreateContainer(_ context.Context, pod *api.PodSandbox, container *api.Container) (_ *api.ContainerAdjustment, _ []*api.ContainerUpdate, err error) {
+func (p *plugin) CreateContainer(ctx context.Context, pod *api.PodSandbox, container *api.Container) (_ *api.ContainerAdjustment, _ []*api.ContainerUpdate, err error) {
 	defer func() {
 		if err != nil {
 			log.Error(err)
@@ -60,6 +61,14 @@ func (p *plugin) CreateContainer(_ context.Context, pod *api.PodSandbox, contain
 		log.Infof("CreateContainer %s", name)
 	}
 
+	allowedCDIDevicesPattern, err := getAllowedCDIDevicesPattern(ctx, pod)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to get allowed CDI devices: %w", err)
+	}
+	if allowedCDIDevicesPattern == "" {
+		return nil, nil, nil
+	}
+
 	cdiDevices, err := parseCdiDevices(pod.Annotations, container.Name)
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to parse CDI Device annotations: %w", err)
@@ -69,14 +78,46 @@ func (p *plugin) CreateContainer(_ context.Context, pod *api.PodSandbox, contain
 		return nil, nil, nil
 	}
 
+	var allowedCDIDevices []string
+	for _, cdiDevice := range cdiDevices {
+		match, _ := filepath.Match(allowedCDIDevicesPattern, cdiDevice)
+		if !match {
+			continue
+		}
+		allowedCDIDevices = append(allowedCDIDevices, cdiDevice)
+	}
+
 	adjust := &api.ContainerAdjustment{}
-	if _, err := p.cdiCache.InjectDevices(adjust, cdiDevices...); err != nil {
+	if _, err := p.cdiCache.InjectDevices(adjust, allowedCDIDevices...); err != nil {
 		return nil, nil, fmt.Errorf("CDI device injection failed: %w", err)
 	}
 
 	return adjust, nil, nil
 }
 
+func getAllowedCDIDevicesPattern(ctx context.Context, pod *api.PodSandbox) (string, error) {
+	namespace := pod.GetNamespace()
+	if namespace == "" {
+		return "", nil
+	}
+
+	annotations, err := getAnnotationsForNamespace(ctx, namespace)
+	if err != nil {
+		return "", fmt.Errorf("could not get annotations for namespace: %w", err)
+	}
+
+	pattern, ok := annotations[cdiDeviceKey+"/allow"]
+	if !ok {
+		return "", nil
+	}
+	return pattern, nil
+}
+
+// TODO: We probably need to use a kubect client here to get the namespace annotations.
+func getAnnotationsForNamespace(_ context.Context, namespace string) (map[string]string, error) {
+	return nil, nil
+}
+
 func parseCdiDevices(annotations map[string]string, ctr string) ([]string, error) {
 	var errs error
 	var cdiDevices []string