Native HTTP support

HTTP sockets

The http-socket <bind> option will make uWSGI natively speak HTTP. If your web server does not support the uwsgi protocol but is able to speak to upstream HTTP proxies, or if you are using a service like Webfaction or Heroku to host your application, you can use http-socket. If you plan to expose your app to the world with uWSGI only, use the http option instead, as the router/proxy/load-balancer will then be your shield.

The uWSGI HTTP/HTTPS router

uWSGI includes an HTTP/HTTPS router/proxy/load-balancer that can forward requests to uWSGI workers. The server can be used in two ways: embedded and standalone. In embedded mode, it will automatically spawn workers and setup the communication socket. In standalone mode you have to specify the address of a uwsgi socket to connect to.

Embedded mode:

./uwsgi --http 127.0.0.1:8080 --master --module mywsgiapp --processes 4

This will spawn a HTTP server on port 8080 that forwards requests to a pool of 4 uWSGI workers managed by the master process.

Standalone mode:

./uwsgi --master --http 127.0.0.1:8080 --http-to /tmp/uwsgi.sock

This will spawn a HTTP router (governed by a master for your safety) that will forward requests to the uwsgi socket /tmp/uwsgi.sock. You can bind to multiple addresses/ports.

[uwsgi]

http = 0.0.0.0:8080
http = 192.168.173.17:8181
http = 127.0.0.1:9090

master = true

http-to = /tmp/uwsgi.sock

And load-balance to multiple nodes:

[uwsgi]

http = 0.0.0.0:8080
http = 192.168.173.17:8181
http = 127.0.0.1:9090

master = true

http-to = /tmp/uwsgi.sock
http-to = 192.168.173.1:3031
http-to = 192.168.173.2:3031
http-to = 192.168.173.3:3031

  • If you want to go massive (virtualhosting and zero-conf scaling) combine the HTTP router with the uWSGI Subscription Server.

  • You can make the HTTP server pass custom uwsgi variables to workers with the http-var KEY=VALUE option.

  • You can use the http-modifier1 option to pass a custom modifier1 value to workers.

HTTPS support

see HTTPS support (from 1.3)

HTTP Keep-Alive

If your backends set the correct HTTP headers, you can use the http-keepalive option. Your backends must either set a valid Content-Length in each response, or you can use chunked encoding with http-auto-chunked. Simply setting “Connection: close” is not enough.

Also remember to set “Connection: Keep-Alive” in your response. You can automate that using the add-header = Connection: Keep-Alive option.

Since uWSGI 2.1 (master branch) you can use the http11-socket option. http11-socket may replace the add-header and http-keepalive options (but it doesn’t touch tcp stuff as so-keepalive does). Once set the server will try to maintain the connection opened if a bunch of rules are respected. This is not a smart http 1.1 parser (to avoid parsing the whole response) but assumes the developer is generating the right headers. http11-socket has been added to support RTSP protocol for video streaming.

HTTP auto gzip

With the http-auto-gzip option, uWSGI can automatically gzip content if the uWSGI-Encoding header is set to gzip while Content-Length and Content-Encoding are not set.

Can I use uWSGI’s HTTP capabilities in production?

If you need a load balancer/proxy it can be a very good idea. It will automatically find new uWSGI instances and can load balance in various ways. If you want to use it as a real webserver you should take into account that serving static files in uWSGI instances is possible, but not as good as using a dedicated full-featured web server. If you host static assets in the cloud or on a CDN, using uWSGI’s HTTP capabilities you can definitely avoid configuring a full webserver.

Note

If you use Amazon’s ELB (Elastic Load Balancer) in HTTP mode in front of uWSGI in HTTP mode, either a valid Content-Length must be set by the backend, or chunked encoding must be used, e.g., with http-auto-chunked. The ELB “health test” may still fail in HTTP mode regardless, in which case a TCP health test can be used instead.

Note

In particular, the Django backend does not set Content-Length by default, while most others do. If running behind ELB, either use chunked encoding as above, or force Django to specify Content-Length with the CommonMiddleware (ConditionalGetMiddleware in Django < 1.11)