Implement Libvirt Serial Console as Console on WebVirtCloud

conf/daemon/consolecallback

@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+# consolecallback - provide a persistent console that survives guest reboots
+
+import os
+import logging
+import libvirt
+import tty
+import termios
+import atexit
+from argparse import ArgumentParser
+from typing import Optional  # noqa F401
+
+
+def reset_term() -> None:
+    termios.tcsetattr(0, termios.TCSADRAIN, attrs)
+
+
+def error_handler(unused, error) -> None:
+    # The console stream errors on VM shutdown; we don't care
+    if error[0] == libvirt.VIR_ERR_RPC and error[1] == libvirt.VIR_FROM_STREAMS:
+        return
+    logging.warn(error)
+
+
+class Console(object):
+    def __init__(self, uri: str, uuid: str) -> None:
+        self.uri = uri
+        self.uuid = uuid
+        self.connection = libvirt.open(uri)
+        self.domain = self.connection.lookupByUUIDString(uuid)
+        self.state = self.domain.state(0)
+        self.connection.domainEventRegister(lifecycle_callback, self)
+        self.stream = None  # type: Optional[libvirt.virStream]
+        self.run_console = True
+        self.stdin_watch = -1
+        logging.info("%s initial state %d, reason %d",
+                     self.uuid, self.state[0], self.state[1])
+
+
+def check_console(console: Console) -> bool:
+    if (console.state[0] == libvirt.VIR_DOMAIN_RUNNING or console.state[0] == libvirt.VIR_DOMAIN_PAUSED):
+        if console.stream is None:
+            console.stream = console.connection.newStream(libvirt.VIR_STREAM_NONBLOCK)
+            console.domain.openConsole(None, console.stream, 0)
+            console.stream.eventAddCallback(libvirt.VIR_STREAM_EVENT_READABLE, stream_callback, console)
+    else:
+        if console.stream:
+            console.stream.eventRemoveCallback()
+            console.stream = None
+
+    return console.run_console
+
+
+def stdin_callback(watch: int, fd: int, events: int, console: Console) -> None:
+    readbuf = os.read(fd, 1024)
+    if readbuf.startswith(b""):
+        console.run_console = False
+        return
+    if console.stream:
+        console.stream.send(readbuf)
+
+
+def stream_callback(stream: libvirt.virStream, events: int, console: Console) -> None:
+    try:
+        assert console.stream
+        received_data = console.stream.recv(1024)
+    except Exception:
+        return
+    os.write(0, received_data)
+
+
+def lifecycle_callback(connection: libvirt.virConnect, domain: libvirt.virDomain, event: int, detail: int, console: Console) -> None:
+    console.state = console.domain.state(0)
+    logging.info("%s transitioned to state %d, reason %d",
+                 console.uuid, console.state[0], console.state[1])
+
+
+# main
+parser = ArgumentParser(epilog="Example: %(prog)s 'qemu:///system' '32ad945f-7e78-c33a-e96d-39f25e025d81'")
+parser.add_argument("uri")
+parser.add_argument("uuid")
+args = parser.parse_args()
+
+print("Escape character is ^]")
+logging.basicConfig(filename='msg.log', level=logging.DEBUG)
+logging.info("URI: %s", args.uri)
+logging.info("UUID: %s", args.uuid)
+
+libvirt.virEventRegisterDefaultImpl()
+libvirt.registerErrorHandler(error_handler, None)
+
+atexit.register(reset_term)
+attrs = termios.tcgetattr(0)
+tty.setraw(0)
+
+console = Console(args.uri, args.uuid)
+console.stdin_watch = libvirt.virEventAddHandle(0, libvirt.VIR_EVENT_HANDLE_READABLE, stdin_callback, console)
+
+while check_console(console):
+    libvirt.virEventRunDefaultImpl()

conf/nginx/webvirtcloud.conf

@@ -28,8 +28,17 @@ server {
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection "upgrade";
     }
+    location /socket.io/ {
+        proxy_pass http://wssocketiod;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+    }
 }
 
 upstream wsnovncd {
       server 127.0.0.1:6080;
-}
+}
+upstream wssocketiod {
+      server 127.0.0.1:6081;
+}

conf/requirements.txt

@@ -13,3 +13,4 @@ rwlock==0.0.7
 websockify==0.10.0
 zipp==3.6.0
 ldap3==2.9.1
+python-socketio==5.7.0

conf/supervisor/webvirtcloud.conf

@@ -12,4 +12,12 @@ directory=/srv/webvirtcloud
 user=www-data
 autostart=true
 autorestart=true
-redirect_stderr=true
+redirect_stderr=true
+
+[program:socketiod]
+command=/srv/webvirtcloud/venv/bin/python3 /srv/webvirtcloud/console/socketiod -d
+directory=/srv/webvirtcloud
+user=www-data
+autostart=true
+autorestart=true
+redirect_stderr=true