Merge "refactor get_console_output() for console logfiles"

nova/virt/libvirt/driver.py

@@ -3119,43 +3119,33 @@ class LibvirtDriver(driver.ComputeDriver):
         xml = guest.get_xml_desc()
         tree = etree.fromstring(xml)
 
-        # If the guest has a console logging to a file prefer to use that
+        # check for different types of consoles
-        file_consoles = tree.findall("./devices/console[@type='file']")
+        path_sources = [
-        if file_consoles:
+            ('file', "./devices/console[@type='file']/source[@path]", 'path'),
-            for file_console in file_consoles:
+            ('pty', "./devices/console[@type='pty']/source[@path]", 'path')]
-                source_node = file_console.find('./source')
+        console_type = ""
-                if source_node is None:
+        console_path = ""
-                    continue
+        for c_type, epath, attrib in path_sources:
-                path = source_node.get("path")
+            node = tree.find(epath)
-                if not path:
+            if (node is not None) and node.get(attrib):
-                    continue
+                console_type = c_type
+                console_path = node.get(attrib)
+                break
 
-                if not os.path.exists(path):
+        # instance has no console at all
-                    LOG.info('Instance is configured with a file console, '
+        if not console_path:
-                             'but the backing file is not (yet?) present',
+            raise exception.ConsoleNotAvailable()
+
+        # instance has a console, but file doesn't exist (yet?)
+        if not os.path.exists(console_path):
+            LOG.info('console logfile for instance does not exist',
                       instance=instance)
             return ""
 
-                return self._get_console_output_file(instance, path)
+        # pty consoles need special handling
-
+        if console_type == 'pty':
-        # Try 'pty' types
-        pty_consoles = tree.findall("./devices/console[@type='pty']")
-        if pty_consoles:
-            for pty_console in pty_consoles:
-                source_node = pty_console.find('./source')
-                if source_node is None:
-                    continue
-                pty = source_node.get("path")
-                if not pty:
-                    continue
-                break
-            else:
-                raise exception.ConsoleNotAvailable()
-        else:
-            raise exception.ConsoleNotAvailable()
-
             console_log = self._get_console_log_path(instance)
-        data = nova.privsep.libvirt.readpty(pty)
+            data = nova.privsep.libvirt.readpty(console_path)
 
             # NOTE(markus_z): The virt_types kvm and qemu are the only ones
             # which create a dedicated file device for the console logging.
@@ -3164,7 +3154,12 @@ class LibvirtDriver(driver.ComputeDriver):
             # that a series of "get_console_output" calls return the complete
             # content even after rebooting a guest.
             nova.privsep.path.writefile(console_log, 'a+', data)
-        return self._get_console_output_file(instance, console_log)
+
+            # set console path to logfile, not to pty device
+            console_path = console_log
+
+        # return logfile content
+        return self._get_console_output_file(instance, console_path)
 
     def get_host_ip_addr(self):
         ips = compute_utils.get_machine_ips()