disk.py: add elements of ssh/https network disk

[meinaLi]

1. Add the new elements for disk source:
   • knownHosts
   • identity
   • ssl
   • readahead
   • timeout
   • cookies
2. Add storage_use_nbdkit which can be used with ssh/https network disks in utils_config.py.

[meinaLi]

This update is related to autotest/tp-libvirt#6251 and autotest/tp-libvirt#6252.

[meinaLi]

@chloerh Please help review this PR, thanks.

[chloerh]

The code looks good, could you please provide a result of setup_attrs() and fetch_attrs() which could be helpful, thanks!

[meinaLi]

The fetch_attrs() result for ssh network disk:

>>> from virttest.libvirt_xml.devices import disk
>>> disk_dev = disk.Disk()
>>> disk_dev.xml = """
... <disk type="network" device="disk">
...   <driver name="qemu" type="qcow2"/>
...   <source protocol="ssh" name="/var/lib/libvirt/images/test.qcow2">
...     <host name="[ssh_server_ip]" port="22"/>
...     <knownHosts path="/tmp/known_hosts"/>
...     <identity username="root" keyfile="/tmp/id_rsa"/>
...   </source>
...   <target dev="sdb" bus="scsi"/>
...   <address type='drive' controller='0' bus='0' target='0' unit='1'/>
... </disk>
... """
>>> disk_dev.fetch_attrs()
{'address': {'type_name': 'drive', 'attrs': {'type': 'drive', 'controller': '0', 'bus': '0', 'target': '0', 'unit': '1'}}, 'type_name': 'network', 'source': {'identity': [{'username': 'root', 'keyfile': '/tmp/id_rsa'}], 'knownhosts': '/tmp/known_hosts', 'attrs': {'protocol': 'ssh', 'name': '/var/lib/libvirt/images/test.qcow2'}, 'hosts': [{'name': '[ssh_server_ip]', 'port': '22'}]}, 'target': {'dev': 'sdb', 'bus': 'scsi'}, 'device': 'disk', 'driver': {'name': 'qemu', 'type': 'qcow2'}}

The setup_attrs() result for ssh network disk:

>>> disk_dev.setup_attrs(**disk_dict)
>>> disk_dev.xml
'/tmp/xml_utils_temp_80gk329h.xml'
# cat /tmp/xml_utils_temp_80gk329h.xml
<disk type="network" device="disk">
  <driver name="qemu" type="qcow2" />
  <target dev="sdb" bus="scsi" />
  <address type="drive" controller="0" bus="0" target="0" unit="1" /><source protocol="ssh" name="/var/lib/libvirt/images/test.qcow2">
    <knownHosts path="/tmp/known_hosts" />
    <identity username="root" keyfile="/tmp/id_rsa" /><host name="[ssh_server_ip]" port="22" /></source></disk>

[meinaLi]

The fetch_attrs() result for https network disk:

>>> disk_dev.xml = """
...     <disk type='network' device='disk'>
...       <driver name='qemu' type='raw'/>
...         <source protocol='https' name='/fedora/linux/releases/41/Workstation/x86_64/iso/Fedora-Server-netinst-x86_64-41-1.4.iso'>
...         <host name='insect.mm.fcix.net' port='443'/>
...         <ssl verify='yes'/>
...         <cookies>
...           <cookie name='vmware_soap_session'>&quot;314455dbd2eaafd7d76b3b7828f0a3e3956450f9&quot;</cookie>
...         </cookies>
...        <readahead size='1024'/>
...         <timeout seconds='1234'/>
...       </source>
...       <target dev='vdb' bus='virtio'/>
...       <readonly/>
...       <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/>
...     </disk>
... """
>>> disk_dev.fetch_attrs()
{'address': {'type_name': 'pci', 'attrs': {'type': 'pci', 'domain': '0x0000', 'bus': '0x07', 'slot': '0x00', 'function': '0x0'}}, 'type_name': 'network', 'source': {'cookies': {'cookie': '"314455dbd2eaafd7d76b3b7828f0a3e3956450f9"', 'cookie_name': 'vmware_soap_session'}, 'ssl': 'yes', 'attrs': {'protocol': 'https', 'name': '/fedora/linux/releases/41/Workstation/x86_64/iso/Fedora-Server-netinst-x86_64-41-1.4.iso'}, 'timeout': '1234', 'hosts': [{'name': 'insect.mm.fcix.net', 'port': '443'}], 'readahead': '1024'}, 'readonly': True, 'target': {'dev': 'vdb', 'bus': 'virtio'}, 'device': 'disk', 'driver': {'name': 'qemu', 'type': 'raw'}}
>>> 

The setup_attrs() result for https network disk:

>>> disk_dev.setup_attrs(**disk_dict)
>>> disk_dev.xml
'/tmp/xml_utils_temp__8fps0u8.xml'
>>> 
# cat /tmp/xml_utils_temp__8fps0u8.xml
<disk type="network" device="disk">
      <driver name="qemu" type="raw" />
        <target dev="vdb" bus="virtio" />
      <readonly />
      <address type="pci" domain="0x0000" bus="0x07" slot="0x00" function="0x0" /><source protocol="https" name="/fedora/linux/releases/41/Workstation/x86_64/iso/Fedora-Server-netinst-x86_64-41-1.4.iso">
        <ssl verify="yes" />
        <readahead size="1024" />
        <timeout seconds="1234" />
      <cookies>
          <cookie name="vmware_soap_session">"314455dbd2eaafd7d76b3b7828f0a3e3956450f9"</cookie>
        </cookies><host name="insect.mm.fcix.net" port="443" /></source></disk>

[chloerh]

Thanks. Approved.

[meinaLi]

@Yingshun Can you help review this PR? It's related to tp-libvirt PR which is in reviewing. This one need to be merged early than others. Thanks.