探究Python的Tornado框架对子域名和泛域名的支持
其实Tornado对子域名和泛域名(除了特别说明外，以下子域名和泛域名均简称为泛域名)的支持并不是什么新鲜事，两年多前我用Tornado写的开源网站 http://poweredsites.org 就有了对泛域名的支持，但是Tornado的官方文档里并没有明确对此功能进行说明，虽然源代码里是有注释的，终是有点隐晦，这不，近日mywaiting同学就遇到了这个问题，我应邀特撰此博文，分享下我对此的一点点经验。
通常，用Tornado添加url映射路由表是直接传handlers给Application这种方式的，比如官方的chatdemo：
class Application(tornado.web.Application):
def __init__(self):
handlers = [
(r"/", MainHandler),
(r"/auth/login", AuthLoginHandler),
(r"/auth/logout", AuthLogoutHandler),
(r"/a/message/new", MessageNewHandler),
(r"/a/message/updates", MessageUpdatesHandler),
]
settings = dict(
cookie_secret="43oETzKXQAGaYdkL5gEmGeJJFuYh7EQnp2XdTP1o/Vo=",
login_url="/auth/login",
template_path=os.path.join(os.path.dirname(__file__), "templates"),
static_path=os.path.join(os.path.dirname(__file__), "static"),
xsrf_cookies=True,
autoescape="xhtml_escape",
)
tornado.web.Application.__init__(self, handlers, **settings)
这种方式其实添加的是一个域名通配的url映射表，即域名&子域名不限，只要访问能够解析到这个chatdemo上，“/auth/login” “/auth/login”这些url就都能够正常运行。假设www.feilong.me、abc.feilong.me、feilong2.me这个三个(子)域名均配置为可由这个chatdemo程序来host，那么访问这三个(子)域名均可以正常使用这个chatdemo，总之域名是无关的。
实际上，这种方式它的内部是通过Application里的这个add_handlers来实现的(原码注释如下)：
def add_handlers(self, host_pattern, host_handlers):
"""Appends the given handlers to our handler list.
Note that host patterns are processed sequentially in the
order they were added, and only the first matching pattern is
used. This means that all handlers for a given host must be
added in a single add_handlers call.
"""
只不过它是隐式的调用这个add_handlers而已，其关键点就在于第一个参数host_pattern(匹配域名的)上，上面那种方式，默认添加的host_pattern是”.*$”，即域名通配，若要支持泛域名，只需要显式的调用add_handlers来添加相应的host_pattern和handlers即可。
接下来就以poweredsites的源码来介绍Tornado对泛域名的支持，app.py里的Application里面有这么几句：
super(Application, self).__init__(handlers, **settings)
# add handlers for sub domains
for sub_handler in sub_handlers:
# host pattern and handlers
self.add_handlers(sub_handler[0], sub_handler[1])
常见的方式super(Application, self).__init__(handlers, **settings)添加的是根域名poweredsites的handlers，接着用for循环显式添加的是子域名和泛域名的handlers。这里的sub_handlers依次放有各子域名的handlers，其最后一个是泛域名的handlers：
sub_handlers.append(site.sub_handlers) sub_handlers.append(blog.sub_handlers) sub_handlers.append(admin.sub_handlers) # wildcard subdomain handler for project should be the last one. sub_handlers.append(project.sub_handlers)
指定的子域名的sub_handlers(site.sub_handlers)是这个样子的，这里的第一个元素就是host_pattern：
sub_handlers = ["^sites.poweredsites.org$",
[
(r"/", _WebsiteIndexHandler),
(r"/feeds", _WebsitesFeedsHandler),
(r"/([a-z0-9]{32})", _WebsiteHandler),
(r"/([^/]+)", WebsiteHandler),
]
]
泛域名(project.sub_handlers)的区别也就在于这第一个元素，即用来做host_pattern的是通配一些子域名的：
sub_handlers = ["^[a-zA-Z_\-0-9]*\.poweredsites.org$",
[(r"/", ProjectIndexHandler),
(r"/top", ProjectTopHandler),
(r"/opensource", ProjectOpensourceHandler),
]
]
在用到了泛域名的ProjectIndexHandler里，运行时具体的子域名就可以通过下面这样的方式获得：
class ProjectIndexHandler(ProjectBaseHandler):
def get(self):
subdomain = self.request.host.split(".")[0]
需要说明的是，Tornado里面的url映射表和Django一样是有顺序的，即url依次序由上到下匹配，只要匹配到就立即结束，不再往下匹配，而带子域名和泛域名的url路由其匹配优先级是要高于通配域名”.*$”的(这个不用你操心，add_handlers会自动为你做到这一点)。同样的，对于泛域名，因为其子域名是通配的，因此指定子域名的handlers需要放到泛域名前添加，如admin、blog这类子域名的handlers要放在泛域名之前，这就是poweredsites里sub_handlers.append(project.sub_handlers)放到最后一条的原因，project这条是对应泛域名的，http://tornado.poweredsites.org 就是靠这一条来实现的。
备注：需要支持泛域名，首先要你的域名解析支持泛域名。
转载请注明出处：http://feilong.me/2012/08/wildcard-subdomain-support-in-tornado
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1658
14
1415
52
1309
25
1257
29
1231
24
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
Choosing Between PHP and Python: A Guide
Apr 18, 2025 am 12:24 AM
PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.
PHP and Python: A Deep Dive into Their History
Apr 18, 2025 am 12:25 AM
PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.
Python vs. JavaScript: The Learning Curve and Ease of Use
Apr 16, 2025 am 12:12 AM
Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
How to run sublime code python
Apr 16, 2025 am 08:48 AM
To run Python code in Sublime Text, you need to install the Python plug-in first, then create a .py file and write the code, and finally press Ctrl B to run the code, and the output will be displayed in the console.
Where to write code in vscode
Apr 15, 2025 pm 09:54 PM
Writing code in Visual Studio Code (VSCode) is simple and easy to use. Just install VSCode, create a project, select a language, create a file, write code, save and run it. The advantages of VSCode include cross-platform, free and open source, powerful features, rich extensions, and lightweight and fast.
Can visual studio code be used in python
Apr 15, 2025 pm 08:18 PM
VS Code can be used to write Python and provides many features that make it an ideal tool for developing Python applications. It allows users to: install Python extensions to get functions such as code completion, syntax highlighting, and debugging. Use the debugger to track code step by step, find and fix errors. Integrate Git for version control. Use code formatting tools to maintain code consistency. Use the Linting tool to spot potential problems ahead of time.
How to run python with notepad
Apr 16, 2025 pm 07:33 PM
Running Python code in Notepad requires the Python executable and NppExec plug-in to be installed. After installing Python and adding PATH to it, configure the command "python" and the parameter "{CURRENT_DIRECTORY}{FILE_NAME}" in the NppExec plug-in to run Python code in Notepad through the shortcut key "F6".
