Add MTU attribute for physical and virtual devices

Signed-off-by: Marcin Franczyk <[email protected]>

Author: mfranczy

docs/usage/customization-guide.md

@@ -968,10 +968,10 @@ The following features are available for matching:
 |                  |              | **`enabled`** | bool  | `true` if swap partition detected, `false` otherwise |
 | **`network.device`** | instance |          |            | Physical (non-virtual) network interfaces present in the system |
 |                  |              | **`name`** | string   | Name of the network interface |
-|                  |              | **`<sysfs-attribute>`** | string | Sysfs network interface attribute, available attributes: `operstate`, `speed`, `sriov_numvfs`, `sriov_totalvfs` |
+|                  |              | **`<sysfs-attribute>`** | string | Sysfs network interface attribute, available attributes: `operstate`, `speed`, `sriov_numvfs`, `sriov_totalvfs`, `mtu` |
 | **`network.virtual`** | instance |          |            | Virtual network interfaces present in the system |
 |                  |              | **`name`** | string   | Name of the network interface |
-|                  |              | **`<sysfs-attribute>`** | string | Sysfs network interface attribute, available attributes: `operstate`, `speed` |
+|                  |              | **`<sysfs-attribute>`** | string | Sysfs network interface attribute, available attributes: `operstate`, `speed`, `mtu` |
 | **`pci.device`** | instance     |          |            | PCI devices present in the system |
 |                  |              | **`<sysfs-attribute>`** | string | Value of the sysfs device attribute, available attributes: `class`, `vendor`, `device`, `subsystem_vendor`, `subsystem_device`, `sriov_totalvfs`, `iommu_group/type`, `iommu/intel-iommu/version` |
 | **`storage.block`** | instance |          |             | Block storage devices present in the system |

source/network/network.go

@@ -60,10 +60,10 @@ var (
 
 var (
 	// devIfaceAttrs is the list of files under /sys/class/net/<iface> that we're reading
-	devIfaceAttrs = []string{"operstate", "speed", "device/sriov_numvfs", "device/sriov_totalvfs"}
+	devIfaceAttrs = []string{"operstate", "speed", "device/sriov_numvfs", "device/sriov_totalvfs", "mtu"}
 
 	// virtualIfaceAttrs is the list of files under /sys/class/net/<iface> that we're reading
-	virtualIfaceAttrs = []string{"operstate", "speed"}
+	virtualIfaceAttrs = []string{"operstate", "speed", "mtu"}
 )
 
 // Name returns an identifier string for this feature source.