Add support for CDI device configuration

- Persist CDIDevices in container config
- Add e2e test
- Log HasDevice error and add additional condition for safety

Signed-off-by: Sebastian Jug <seb@stianj.ug>

vendor/github.com/container-orchestrated-devices/container-device-interface/pkg/devices.go

@@ -0,0 +1,180 @@
+package pkg
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	cdispec "github.com/container-orchestrated-devices/container-device-interface/specs-go"
+	spec "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+const (
+	root = "/etc/cdi"
+)
+
+func collectCDISpecs() (map[string]*cdispec.Spec, error) {
+	var files []string
+	vendor := make(map[string]*cdispec.Spec)
+
+	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
+		if info == nil || info.IsDir() {
+			return nil
+		}
+
+		if filepath.Ext(path) != ".json" {
+			return nil
+		}
+
+		files = append(files, path)
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	for _, path := range files {
+		spec, err := loadCDIFile(path)
+		if err != nil {
+			continue
+		}
+
+		if _, ok := vendor[spec.Kind]; ok {
+			continue
+		}
+
+		vendor[spec.Kind] = spec
+	}
+
+	return vendor, nil
+}
+
+// TODO: Validate (e.g: duplicate device names)
+func loadCDIFile(path string) (*cdispec.Spec, error) {
+	file, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var spec *cdispec.Spec
+	err = json.Unmarshal([]byte(file), &spec)
+	if err != nil {
+		return nil, err
+	}
+
+	return spec, nil
+}
+
+/*
+* Pattern "vendor.com/device=myDevice" with the vendor being optional
+ */
+func extractVendor(dev string) (string, string) {
+	if strings.IndexByte(dev, '=') == -1 {
+		return "", dev
+	}
+
+	split := strings.SplitN(dev, "=", 2)
+	return split[0], split[1]
+}
+
+// GetCDIForDevice returns the CDI specification that matches the device name the user provided.
+func GetCDIForDevice(dev string, specs map[string]*cdispec.Spec) (*cdispec.Spec, error) {
+	vendor, device := extractVendor(dev)
+
+	if vendor != "" {
+		s, ok := specs[vendor]
+		if !ok {
+			return nil, fmt.Errorf("Could not find vendor %q for device %q", vendor, device)
+		}
+
+		for _, d := range s.Devices {
+			if d.Name != device {
+				continue
+			}
+
+			return s, nil
+		}
+
+		return nil, fmt.Errorf("Could not find device %q for vendor %q", device, vendor)
+	}
+
+	var found []*cdispec.Spec
+	var vendors []string
+	for vendor, spec := range specs {
+
+		for _, d := range spec.Devices {
+			if d.Name != device {
+				continue
+			}
+
+			found = append(found, spec)
+			vendors = append(vendors, vendor)
+		}
+	}
+
+	if len(found) > 1 {
+		return nil, fmt.Errorf("%q is ambiguous and currently refers to multiple devices from different vendors: %q", dev, vendors)
+	}
+
+	if len(found) == 1 {
+		return found[0], nil
+	}
+
+	return nil, fmt.Errorf("Could not find device %q", dev)
+}
+
+// HasDevice returns true if a device is a CDI device
+// an error may be returned in cases where permissions may be required
+func HasDevice(dev string) (bool, error) {
+	specs, err := collectCDISpecs()
+	if err != nil {
+		return false, err
+	}
+
+	d, err := GetCDIForDevice(dev, specs)
+	if err != nil {
+		return false, err
+	}
+
+	return d != nil, nil
+}
+
+// UpdateOCISpecForDevices updates the given OCI spec based on the requested CDI devices
+func UpdateOCISpecForDevices(ociconfig *spec.Spec, devs []string) error {
+	specs, err := collectCDISpecs()
+	if err != nil {
+		return err
+	}
+
+	return UpdateOCISpecForDevicesWithSpec(ociconfig, devs, specs)
+}
+
+// UpdateOCISpecForDevicesWithLoggerAndSpecs is mainly used for testing
+func UpdateOCISpecForDevicesWithSpec(ociconfig *spec.Spec, devs []string, specs map[string]*cdispec.Spec) error {
+	edits := make(map[string]*cdispec.Spec)
+
+	for _, d := range devs {
+		spec, err := GetCDIForDevice(d, specs)
+		if err != nil {
+			return err
+		}
+
+		edits[spec.Kind] = spec
+		err = cdispec.ApplyOCIEditsForDevice(ociconfig, spec, d)
+		if err != nil {
+			return err
+		}
+	}
+
+	for _, spec := range edits {
+		if err := cdispec.ApplyOCIEdits(ociconfig, spec); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}