ASP.NET vNext, enable compression to IIS 8 on Azure? - asp.net-core

Question

how would one enable gzip compression of responses with Content-Type application/json when the asp.net 5 app is deployed to IIS 8 on Azure? Typically this would've been done using web.config but that's gone now... what's the new approach?

Answer 1

You need to reverse-proxy your kestrel application, then you can tell the reverse-proxy to compress.
In nginx, this goes as follows:
server {
listen 80 default_server;
listen [::]:80 default_server ipv6only=on;
server_name localhost;
gzip on;
gzip_min_length 1000;
#gzip_proxied expired no-cache no-store private auth;
gzip_proxied any;
gzip_comp_level 6;
gzip_buffers 16 8k;
gzip_http_version 1.1;
gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;
gzip_vary on;
gzip_disable "MSIE [1-6]\.(?!.*SV1)";
location /
{
proxy_pass http://127.0.0.1:5004;
}
}
So here nginx will catch incoming requests on port 80, and then forward them to kestrel on the same machine, but on port 5004. Kestrel then sends the response back to nginx. Since gzip is on, nginx will compress the response, and send it to the user. All you need to ensure is that the application on Kestrel does not return HTTP headers, such as HTTP 1.1 chuncked-encoding when outputting for example a file (e.g. when using what used-to-be Response.TransmitFile).
IIS 7.5+ supports reverse proxying.
See here for closer information:
https://serverfault.com/questions/47537/can-iis-be-configure-to-forward-request-to-another-web-server