Add usb support to libvirt-vm role (#95)

* Update Readme for USB support

* Add usb_devices var to include vm.yml

* adding include to validate presence of usb devices on host

* adding usb section to vm.xml template

* adding include to validate usb devices

* moving to faile_when for cleaner handling of errors

* remove loop index as Libvirt fills in data

README.md

@@ -120,6 +120,27 @@ Role Variables
         - `dev`: (optional) Block device path when type is `block`.
         - `remote_src`: (optional) When type is `file` or `block`, specify wether `image` points to a remote file (true) or a file local to the host that launched the playbook (false). Defaults to true.
 
+    - `usb_devices`: a list of usb devices to present to the vm from the host.
+
+      Each usb device is defined with the following dict:
+
+        - `vendor`: The vendor id of the USB device. 
+        - `product`: The product id of the USB device.
+
+      Note - Libvirt will error if the VM is provisioned and the USB device is not attached.
+
+      To obtain the vendor id and product id of the usb device from the host running as sudo / root with the usb device plugged in
+      run `lsusb -v`. Example below with an attached Sandisk USB Memory Stick with vendor id: `0x0781` and product id: `0x5567`
+
+      ```
+      lsusb -v | grep -A4 -i sandisk
+
+        idVendor           0x0781 SanDisk Corp.
+        idProduct          0x5567 Cruzer Blade
+        bcdDevice            1.00
+        iManufacturer           1 
+        iProduct                2 
+      ```
 
     - `interfaces`: a list of network interfaces to attach to the VM.
       Each network interface is defined with the following dict:
@@ -231,6 +252,10 @@ Example Playbook
 
               interfaces:
                 - network: 'br-datacentre'
+              
+              usb_devices:
+                - vendor: '0x0781'
+                  product: '0x5567'
 
             - state: present
               name: 'vm2'

tasks/check-usb-devices.yml

@@ -0,0 +1,15 @@
+---
+- name: List USB hardware
+  command: lsusb  -d {{ usb_device.vendor }}:{{ usb_device.product }}
+  register: host_attached_usb_device
+  become: true
+  changed_when: false 
+  failed_when: false
+
+- name: Check USB device is present on Host system
+  fail:
+    msg: >
+      The USB Device with Vendor ID:{{ usb_device.vendor }} and Product ID:{{ usb_device.product }} is not seen on host system
+      Is the USB device plugged in correctly ?
+  when:
+    - host_attached_usb_device.rc != 0

tasks/main.yml

@@ -41,6 +41,7 @@
     cpu_mode: "{{ vm.cpu_mode | default(libvirt_cpu_mode_default) }}"
     volumes: "{{ vm.volumes | default([], true) }}"
     interfaces: "{{ vm.interfaces | default([], true) }}"
+    usb_devices: "{{ vm.usb_devices | default([], false) }}"
     start: "{{ vm.start | default(true) }}"
     autostart: "{{ vm.autostart | default(true) }}"
     enable_vnc: "{{ vm.enable_vnc | default(false) }}"

tasks/vm.yml

@@ -16,6 +16,12 @@
     interface: "{{ item }}"
   with_items: "{{ interfaces }}"
 
+- name: Validate Host USB Devices
+  include_tasks: check-usb-devices.yml
+  vars:
+    usb_device: "{{ item }}"
+  with_items: "{{ usb_devices }}"
+
 - name: Ensure the VM is defined
   virt:
     command: define

templates/vm.xml.j2

@@ -124,6 +124,14 @@
       <listen type='address'/>
     </graphics>
 {% endif %}
+{% for usb_device in usb_devices %}
+    <hostdev mode='subsystem' type='usb' managed='yes'>
+      <source>
+        <vendor id='{{ usb_device.vendor }}'/>
+        <product id='{{ usb_device.product }}'/>
+      </source>
+    </hostdev>
+  {% endfor %}
     <rng model="virtio"><backend model="random">/dev/urandom</backend></rng>
   </devices>
 </domain>