Support device id in host device plugin (#471)

* Add support for `deviceID` runtime config attribute

Signed-off-by: Adrian Chiris <[email protected]>

plugins/main/host-device/README.md

@@ -17,6 +17,9 @@ The device can be specified with any one of four properties:
 
 For this plugin, `CNI_IFNAME` will be ignored. Upon DEL, the device will be moved back.
 
+The plugin also supports the following [capability argument](https://github.com/containernetworking/cni/blob/master/CONVENTIONS.md):
+* `deviceID`: A PCI address of the network device, e.g `0000:00:1f.6`
+
 ## Example configuration
 
 A sample configuration with `device` property looks like:
@@ -38,3 +41,26 @@ A sample configuration with `pciBusID` property looks like:
 	"pciBusID": "0000:3d:00.1"
 }
 ```
+
+A sample configuration utilizing `deviceID` runtime configuration looks like:
+
+1. From operator perspective:
+     ```json
+    {
+    	"cniVersion": "0.3.1",
+    	"type": "host-device",
+    	"capabilities": {
+    		"deviceID":  true
+    	}
+    }
+    ```
+2. From plugin perspective:
+    ```json
+    {
+    	"cniVersion": "0.3.1",
+    	"type": "host-device",
+    	"runtimeConfig": {
+    		"deviceID":  "0000:3d:00.1"
+    	}
+    }
+    ```

plugins/main/host-device/host-device.go

@@ -46,10 +46,13 @@ const (
 //NetConf for host-device config, look the README to learn how to use those parameters
 type NetConf struct {
 	types.NetConf
-	Device     string `json:"device"`     // Device-Name, something like eth0 or can0 etc.
-	HWAddr     string `json:"hwaddr"`     // MAC Address of target network interface
-	KernelPath string `json:"kernelpath"` // Kernelpath of the device
-	PCIAddr    string `json:"pciBusID"`   // PCI Address of target network device
+	Device        string `json:"device"`     // Device-Name, something like eth0 or can0 etc.
+	HWAddr        string `json:"hwaddr"`     // MAC Address of target network interface
+	KernelPath    string `json:"kernelpath"` // Kernelpath of the device
+	PCIAddr       string `json:"pciBusID"`   // PCI Address of target network device
+	RuntimeConfig struct {
+		DeviceID string `json:"deviceID,omitempty"`
+	} `json:"runtimeConfig,omitempty"`
 }
 
 func init() {
@@ -64,9 +67,16 @@ func loadConf(bytes []byte) (*NetConf, error) {
 	if err := json.Unmarshal(bytes, n); err != nil {
 		return nil, fmt.Errorf("failed to load netconf: %v", err)
 	}
+
+	if n.RuntimeConfig.DeviceID != "" {
+		// Override PCI device with the standardized DeviceID provided in Runtime Config.
+		n.PCIAddr = n.RuntimeConfig.DeviceID
+	}
+
 	if n.Device == "" && n.HWAddr == "" && n.KernelPath == "" && n.PCIAddr == "" {
 		return nil, fmt.Errorf(`specify either "device", "hwaddr", "kernelpath" or "pciBusID"`)
 	}
+
 	return n, nil
 }