virt: adding kernel boot parameters to libvirt xml

salt/modules/virt.py

@@ -107,6 +107,8 @@
 import salt.utils.validate.net
 import salt.utils.versions
 import salt.utils.yaml
+
+from salt.utils.virt import check_remote, download_remote
 from salt.exceptions import CommandExecutionError, SaltInvocationError
 from salt.ext import six
 from salt.ext.six.moves import range  # pylint: disable=import-error,redefined-builtin
@@ -120,6 +122,8 @@
     )
 )
 
+CACHE_DIR = '/var/lib/libvirt/saltinst'
+
 VIRT_STATE_NAME_MAP = {0: 'running',
                        1: 'running',
                        2: 'running',
@@ -533,6 +537,7 @@ def _gen_xml(name,
              os_type,
              arch,
              graphics=None,
+             boot=None,
              **kwargs):
     '''
     Generate the XML string to define a libvirt VM
@@ -569,11 +574,15 @@ def _gen_xml(name,
     else:
         context['boot_dev'] = ['hd']
 
+    context['boot'] = boot if boot else {}
+
     if os_type == 'xen':
         # Compute the Xen PV boot method
         if __grains__['os_family'] == 'Suse':
-            context['kernel'] = '/usr/lib/grub2/x86_64-xen/grub.xen'
-            context['boot_dev'] = []
+            if not boot or not boot.get('kernel', None):
+                context['boot']['kernel'] = \
+                        '/usr/lib/grub2/x86_64-xen/grub.xen'
+                context['boot_dev'] = []
 
     if 'serial_type' in kwargs:
         context['serial_type'] = kwargs['serial_type']
@@ -1141,6 +1150,34 @@ def _get_merged_nics(hypervisor, profile, interfaces=None, dmac=None):
     return nicp
 
 
+def _handle_remote_boot_params(orig_boot):
+    """
+    Checks if the boot parameters contain a remote path. If so, it will copy
+    the parameters, download the files specified in the remote path, and return
+    a new dictionary with updated paths containing the canonical path to the
+    kernel and/or initrd
+
+    :param orig_boot: The original boot parameters passed to the init or update
+    functions.
+    """
+    saltinst_dir = None
+    new_boot = orig_boot.copy()
+
+    try:
+        for key in ['kernel', 'initrd']:
+            if check_remote(orig_boot.get(key)):
+                if saltinst_dir is None:
+                    os.makedirs(CACHE_DIR)
+                    saltinst_dir = CACHE_DIR
+
+                new_boot[key] = download_remote(orig_boot.get(key),
+                                                saltinst_dir)
+
+        return new_boot
+    except Exception as err:
+        raise err
+
+
 def init(name,
          cpu,
          mem,
@@ -1162,6 +1199,7 @@ def init(name,
          graphics=None,
          os_type=None,
          arch=None,
+         boot=None,
          **kwargs):
     '''
     Initialize a new vm
@@ -1292,6 +1330,22 @@ def init(name,
     :param password: password to connect with, overriding defaults
 
                      .. versionadded:: 2019.2.0
+    :param boot:
+        Specifies kernel for the virtual machine, as well as boot parameters
+        for the virtual machine. This is an optionl parameter, and all of the
+        keys are optional within the dictionary. If a remote path is provided
+        to kernel or initrd, salt will handle the downloading of the specified
+        remote fild, and will modify the XML accordingly.
+
+        .. code-block:: python
+
+            {
+                'kernel': '/root/f8-i386-vmlinuz',
+                'initrd': '/root/f8-i386-initrd',
+                'cmdline': 'console=ttyS0 ks=http://example.com/f8-i386/os/'
+            }
+
+        .. versionadded:: neon
 
     .. _init-nic-def:
 
@@ -1539,7 +1593,11 @@ def init(name,
     if arch is None:
         arch = 'x86_64' if 'x86_64' in arches else arches[0]
 
-    vm_xml = _gen_xml(name, cpu, mem, diskp, nicp, hypervisor, os_type, arch, graphics, **kwargs)
+    if boot is not None:
+        boot = _handle_remote_boot_params(boot)
+
+    vm_xml = _gen_xml(name, cpu, mem, diskp, nicp, hypervisor, os_type, arch,
+                      graphics, boot, **kwargs)
     conn = __get_conn(**kwargs)
     try:
         conn.defineXML(vm_xml)
@@ -1718,6 +1776,7 @@ def update(name,
            interfaces=None,
            graphics=None,
            live=True,
+           boot=None,
            **kwargs):
     '''
     Update the definition of an existing domain.
@@ -1753,6 +1812,23 @@ def update(name,
     :param username: username to connect with, overriding defaults
     :param password: password to connect with, overriding defaults
 
+    :param boot:
+        Specifies kernel for the virtual machine, as well as boot parameters
+        for the virtual machine. This is an optionl parameter, and all of the
+        keys are optional within the dictionary. If a remote path is provided
+        to kernel or initrd, salt will handle the downloading of the specified
+        remote fild, and will modify the XML accordingly.
+
+        .. code-block:: python
+
+            {
+                'kernel': '/root/f8-i386-vmlinuz',
+                'initrd': '/root/f8-i386-initrd',
+                'cmdline': 'console=ttyS0 ks=http://example.com/f8-i386/os/'
+            }
+
+        .. versionadded:: neon
+
     :return:
 
         Returns a dictionary indicating the status of what has been done. It is structured in
@@ -1793,6 +1869,10 @@ def update(name,
     # Compute the XML to get the disks, interfaces and graphics
     hypervisor = desc.get('type')
     all_disks = _disk_profile(disk_profile, hypervisor, disks, name, **kwargs)
+
+    if boot is not None:
+        boot = _handle_remote_boot_params(boot)
+
     new_desc = ElementTree.fromstring(_gen_xml(name,
                                                cpu,
                                                mem,
@@ -1802,6 +1882,7 @@ def update(name,
                                                domain.OSType(),
                                                desc.find('.//os/type').get('arch'),
                                                graphics,
+                                               boot,
                                                **kwargs))
 
     # Update the cpu
@@ -1811,6 +1892,48 @@ def update(name,
         cpu_node.set('current', six.text_type(cpu))
         need_update = True
 
+    # Update the kernel boot parameters
+    boot_tags = ['kernel', 'initrd', 'cmdline']
+    parent_tag = desc.find('os')
+
+    # We need to search for each possible subelement, and update it.
+    for tag in boot_tags:
+        # The Existing Tag...
+        found_tag = desc.find(tag)
+
+        # The new value
+        boot_tag_value = boot.get(tag, None) if boot else None
+
+        # Existing tag is found and values don't match
+        if found_tag and found_tag.text != boot_tag_value:
+
+            # If the existing tag is found, but the new value is None
+            # remove it. If the existing tag is found, and the new value
+            # doesn't match update it. In either case, mark for update.
+            if boot_tag_value is None \
+               and boot is not None   \
+               and parent_tag is not None:
+                ElementTree.remove(parent_tag, tag)
+            else:
+                found_tag.text = boot_tag_value
+
+            need_update = True
+
+        # Existing tag is not found, but value is not None
+        elif found_tag is None and boot_tag_value is not None:
+
+            # Need to check for parent tag, and add it if it does not exist.
+            # Add a subelement and set the value to the new value, and then
+            # mark for update.
+            if parent_tag is not None:
+                child_tag = ElementTree.SubElement(parent_tag, tag)
+            else:
+                new_parent_tag = ElementTree.Element('os')
+                child_tag = ElementTree.SubElement(new_parent_tag, tag)
+
+            child_tag.text = boot_tag_value
+            need_update = True
+
     # Update the memory, note that libvirt outputs all memory sizes in KiB
     for mem_node_name in ['memory', 'currentMemory']:
         mem_node = desc.find(mem_node_name)

salt/states/virt.py

@@ -264,7 +264,8 @@ def running(name,
             username=None,
             password=None,
             os_type=None,
-            arch=None):
+            arch=None,
+            boot=None):
     '''
     Starts an existing guest, or defines and starts a new VM with specified arguments.
 
@@ -349,6 +350,23 @@ def running(name,
 
         .. versionadded:: Neon
 
+    :param boot:
+        Specifies kernel for the virtual machine, as well as boot parameters
+        for the virtual machine. This is an optionl parameter, and all of the
+        keys are optional within the dictionary. If a remote path is provided
+        to kernel or initrd, salt will handle the downloading of the specified
+        remote fild, and will modify the XML accordingly.
+
+        .. code-block:: python
+
+            {
+                'kernel': '/root/f8-i386-vmlinuz',
+                'initrd': '/root/f8-i386-initrd',
+                'cmdline': 'console=ttyS0 ks=http://example.com/f8-i386/os/'
+            }
+
+        .. versionadded:: neon
+
     .. rubric:: Example States
 
     Make sure an already-defined virtual machine called ``domain_name`` is running:
@@ -413,7 +431,8 @@ def running(name,
                                                      live=False,
                                                      connection=connection,
                                                      username=username,
-                                                     password=password)
+                                                     password=password,
+                                                     boot=boot)
                     if status['definition']:
                         action_msg = 'updated and started'
                 __salt__['virt.start'](name)
@@ -431,7 +450,8 @@ def running(name,
                                                      graphics=graphics,
                                                      connection=connection,
                                                      username=username,
-                                                     password=password)
+                                                     password=password,
+                                                     boot=boot)
                     ret['changes'][name] = status
                     if status.get('errors', None):
                         ret['comment'] = 'Domain {0} updated, but some live update(s) failed'.format(name)
@@ -466,7 +486,8 @@ def running(name,
                                   priv_key=priv_key,
                                   connection=connection,
                                   username=username,
-                                  password=password)
+                                  password=password,
+                                  boot=boot)
             ret['changes'][name] = 'Domain defined and started'
             ret['comment'] = 'Domain {0} defined and started'.format(name)
     except libvirt.libvirtError as err:

salt/templates/virt/libvirt_domain.jinja

@@ -5,7 +5,17 @@
         <currentMemory unit='KiB'>{{ mem }}</currentMemory>
         <os>
                 <type arch='{{ arch }}'>{{ os_type }}</type>
-                {% if kernel %}<kernel>{{ kernel }}</kernel>{% endif %}
+                {% if boot %}
+                  {% if 'kernel' in boot %}
+                    <kernel>{{ boot.kernel }}</kernel>
+                  {% endif %}
+                  {% if 'initrd' in boot %}
+                    <initrd>{{ boot.initrd }}</initrd>
+                  {% endif %}
+                  {% if 'cmdline' in boot %}
+                    <cmdline>{{ boot.cmdline }}</cmdline>
+                  {% endif %}
+                {% endif %}
                 {% for dev in boot_dev %}
                 <boot dev='{{ dev }}' />
                 {% endfor %}

salt/utils/virt.py

@@ -6,16 +6,59 @@
 
 # Import python libs
 import os
+import re
 import time
 import logging
+import hashlib
+
+# pylint: disable=E0611
+from salt.ext.six.moves.urllib.parse import urlparse
+from salt.ext.six.moves.urllib import request
 
 # Import salt libs
 import salt.utils.files
 
-
 log = logging.getLogger(__name__)
 
 
+def download_remote(url, dir):
+    """
+    Attempts to download a file specified by 'url'
+
+    :param url: The full remote path of the file which should be downloaded.
+    :param dir: The path the file should be downloaded to.
+    """
+
+    try:
+        rand = hashlib.md5(os.urandom(32)).hexdigest()
+        remote_filename = urlparse(url).path.split('/')[-1]
+        full_directory = \
+            os.path.join(dir, "{}-{}".format(rand, remote_filename))
+        with salt.utils.files.fopen(full_directory, 'wb') as file,\
+                request.urlopen(url) as response:
+            file.write(response.rease())
+
+        return full_directory
+
+    except Exception as err:
+        raise err
+
+
+def check_remote(cmdline_path):
+    """
+    Checks to see if the path provided contains ftp, http, or https. Returns
+    the full path if it is found.
+
+    :param cmdline_path: The path to the initrd image or the kernel
+    """
+    regex = re.compile('^(ht|f)tps?\\b')
+
+    if regex.match(urlparse(cmdline_path).scheme):
+        return True
+
+    return False
+
+
 class VirtKey(object):
     '''
     Used to manage key signing requests.