前言
最近工作中需要開發前端操作遠程虛擬機的功能,簡稱WebShell. 基于當前的技術棧為react+django,調研了一會發現大部分的后端實現都是django+channels來實現websocket服務.
大致看了下覺得這不夠有趣,翻了翻django的官方文檔發現django原生是不支持websocket的,但django3之后支持了asgi協議可以自己實現websocket服務. 于是選定
gunicorn+uvicorn+asgi+websocket+django3.2+paramiko來實現WebShell.
實現websocket服務
使用django自帶的腳手架生成的項目會自動生成asgi.py和wsgi.py兩個文件,普通應用大部分用的都是wsgi.py配合nginx部署線上服務. 這次主要使用asgi.py
實現websocket服務的思路大致網上搜一下就能找到,主要就是實現 connect/send/receive/disconnect這個幾個動作的處理方法.
這里 How to Add Websockets to a Django App without Extra Dependencies 就是一個很好的實例
, 但過于簡單........:
思路
# asgi.py
import os
from django.core.asgi import get_asgi_application
from websocket_app.websocket import websocket_application
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'websocket_app.settings')
django_application = get_asgi_application()
async def application(scope, receive, send):
if scope['type'] == 'http':
await django_application(scope, receive, send)
elif scope['type'] == 'websocket':
await websocket_application(scope, receive, send)
else:
raise NotImplementedError(f"Unknown scope type {scope['type']}")
# websocket.py
async def websocket_application(scope, receive, send):
pass
# websocket.py
async def websocket_application(scope, receive, send):
while True:
event = await receive()
if event['type'] == 'websocket.connect':
await send({
'type': 'websocket.accept'
})
if event['type'] == 'websocket.disconnect':
break
if event['type'] == 'websocket.receive':
if event['text'] == 'ping':
await send({
'type': 'websocket.send',
'text': 'pong!'
})
實現
上面的代碼提供了思路,比較完整的可以參考這里 websockets-in-django-3-1 基本可以復用了
其中最核心的實現部分我放下面:
class WebSocket:
def __init__(self, scope, receive, send):
self._scope = scope
self._receive = receive
self._send = send
self._client_state = State.CONNECTING
self._app_state = State.CONNECTING
@property
def headers(self):
return Headers(self._scope)
@property
def scheme(self):
return self._scope["scheme"]
@property
def path(self):
return self._scope["path"]
@property
def query_params(self):
return QueryParams(self._scope["query_string"].decode())
@property
def query_string(self) -> str:
return self._scope["query_string"]
@property
def scope(self):
return self._scope
async def accept(self, subprotocol: str = None):
"""Accept connection.
:param subprotocol: The subprotocol the server wishes to accept.
:type subprotocol: str, optional
"""
if self._client_state == State.CONNECTING:
await self.receive()
await self.send({"type": SendEvent.ACCEPT, "subprotocol": subprotocol})
async def close(self, code: int = 1000):
await self.send({"type": SendEvent.CLOSE, "code": code})
async def send(self, message: t.Mapping):
if self._app_state == State.DISCONNECTED:
raise RuntimeError("WebSocket is disconnected.")
if self._app_state == State.CONNECTING:
assert message["type"] in {SendEvent.ACCEPT, SendEvent.CLOSE}, (
'Could not write event "%s" into socket in connecting state.'
% message["type"]
)
if message["type"] == SendEvent.CLOSE:
self._app_state = State.DISCONNECTED
else:
self._app_state = State.CONNECTED
elif self._app_state == State.CONNECTED:
assert message["type"] in {SendEvent.SEND, SendEvent.CLOSE}, (
'Connected socket can send "%s" and "%s" events, not "%s"'
% (SendEvent.SEND, SendEvent.CLOSE, message["type"])
)
if message["type"] == SendEvent.CLOSE:
self._app_state = State.DISCONNECTED
await self._send(message)
async def receive(self):
if self._client_state == State.DISCONNECTED:
raise RuntimeError("WebSocket is disconnected.")
message = await self._receive()
if self._client_state == State.CONNECTING:
assert message["type"] == ReceiveEvent.CONNECT, (
'WebSocket is in connecting state but received "%s" event'
% message["type"]
)
self._client_state = State.CONNECTED
elif self._client_state == State.CONNECTED:
assert message["type"] in {ReceiveEvent.RECEIVE, ReceiveEvent.DISCONNECT}, (
'WebSocket is connected but received invalid event "%s".'
% message["type"]
)
if message["type"] == ReceiveEvent.DISCONNECT:
self._client_state = State.DISCONNECTED
return message
縫合怪
做為合格的代碼搬運工,為了提高搬運效率還是要造點輪子填點坑的,如何將上面的WebSocket類與paramiko結合起來實現從前端接受字符傳遞給遠程主機并同時接受返回呢?
import asyncio
import traceback
import paramiko
from webshell.ssh import Base, RemoteSSH
from webshell.connection import WebSocket
class WebShell:
"""整理 WebSocket 和 paramiko.Channel,實現兩者的數據互通"""
def __init__(self, ws_session: WebSocket,
ssh_session: paramiko.SSHClient = None,
chanel_session: paramiko.Channel = None
):
self.ws_session = ws_session
self.ssh_session = ssh_session
self.chanel_session = chanel_session
def init_ssh(self, host=None, port=22, user="admin", passwd="admin@123"):
self.ssh_session, self.chanel_session = RemoteSSH(host, port, user, passwd).session()
def set_ssh(self, ssh_session, chanel_session):
self.ssh_session = ssh_session
self.chanel_session = chanel_session
async def ready(self):
await self.ws_session.accept()
async def welcome(self):
# 展示Linux歡迎相關內容
for i in range(2):
if self.chanel_session.send_ready():
message = self.chanel_session.recv(2048).decode('utf-8')
if not message:
return
await self.ws_session.send_text(message)
async def web_to_ssh(self):
# print('--------web_to_ssh------->')
while True:
# print('--------------->')
if not self.chanel_session.active or not self.ws_session.status:
return
await asyncio.sleep(0.01)
shell = await self.ws_session.receive_text()
# print('-------shell-------->', shell)
if self.chanel_session.active and self.chanel_session.send_ready():
self.chanel_session.send(bytes(shell, 'utf-8'))
# print('--------------->', "end")
async def ssh_to_web(self):
# print('--------ssh_to_web-----------')
while True:
# print('-------------------')
if not self.chanel_session.active:
await self.ws_session.send_text('ssh closed')
return
if not self.ws_session.status:
return
await asyncio.sleep(0.01)
if self.chanel_session.recv_ready():
message = self.chanel_session.recv(2048).decode('utf-8')
# print('---------message----------', message)
if not len(message):
continue
await self.ws_session.send_text(message)
# print('-------------------', "end")
async def run(self):
if not self.ssh_session:
raise Exception("ssh not init!")
await self.ready()
await asyncio.gather(
self.web_to_ssh(),
self.ssh_to_web()
)
def clear(self):
try:
self.ws_session.close()
except Exception:
traceback.print_stack()
try:
self.ssh_session.close()
except Exception:
traceback.print_stack()
前端
xterm.js 完全滿足,搜索下找個看著簡單的就行.
export class Term extends React.Component {
private terminal!: HTMLDivElement;
private fitAddon = new FitAddon();
componentDidMount() {
const xterm = new Terminal();
xterm.loadAddon(this.fitAddon);
xterm.loadAddon(new WebLinksAddon());
// using wss for https
// const socket = new WebSocket("ws://" + window.location.host + "/api/v1/ws");
const socket = new WebSocket("ws://localhost:8000/webshell/");
// socket.onclose = (event) => {
// this.props.onClose();
// }
socket.onopen = (event) => {
xterm.loadAddon(new AttachAddon(socket));
this.fitAddon.fit();
xterm.focus();
}
xterm.open(this.terminal);
xterm.onResize(({ cols, rows }) => {
socket.send("RESIZE>" + cols + "," + rows)
});
window.addEventListener('resize', this.onResize);
}
componentWillUnmount() {
window.removeEventListener('resize', this.onResize);
}
onResize = () => {
this.fitAddon.fit();
}
render() {
return div className="Terminal" ref={(ref) => this.terminal = ref as HTMLDivElement}>/div>;
}
}
好了,廢話不多少了,代碼我放這里了webshell 歡迎star/fork!
參考資料
webshell
django文檔
graphene-django文檔
django 異步視圖
websockets-in-django-3-1
How to Add Websockets to a Django App without Extra Dependencies
到此這篇關于Django3使用WebSocket實現WebShell的文章就介紹到這了,更多相關Django3實現WebShell內容請搜索腳本之家以前的文章或繼續瀏覽下面的相關文章希望大家以后多多支持腳本之家！
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