Nginx config with some conditionals

Question

This config has 3 main features but there seems to be a lot of duplication and I wonder if I could improve it.

1 Detect all pngs and jpgs in static/img and try a webp version if the requesting browser supports it

2 Detect non-ES6 supporting browsers and serve site.babel.js, otherwise serve site.js which is un-babelified

3 Proxy all other requests to a node app running on port 3000

upstream node_upstream {
 server node:3000;
 keepalive 64;
}
#Required since SSL termination is higher up at the AWS load balancer
map $http_x_forwarded_proto $is_https {
 default off;
 https on;
}
map $http_accept $webp_suffix {
 default "";
 "~*webp" ".webp";
}
map $http_user_agent $script_file {
 default "site.js";
 "~MSIE" "site.babel.js";
 "~Trident" "site.babel.js";
 "~Opera.*Version/[0-9]\." "site.babel.js";
 "~Opera.*Version/[0-1][0-9]\." "site.babel.js";
 "~Opera.*Version/2[0-1]\." "site.babel.js";
 "~AppleWebKit.*Version/[0-9]\..*Safari" "site.babel.js";
 "~Chrome/[0-9]\." "site.babel.js";
 "~Chrome/[0-2][0-9]\." "site.babel.js";
 "~Chrome/3[0-3]\." "site.babel.js";
 "~Chrome/4[0-3]\." "site.babel.js";
 "~Edge/1[0-3]\." "site.babel.js";
}
server {
 root /var/www/html/src;
 gzip on;
 # AWS traffic will come via a load balancer with the original protocol stored in http_x_forwarded_proto
 # If this is set to http then we need to redirect any request onto https equivalent
 # Should be ignored in non AWS environment as http_x_forwarded_proto should not be set
 if ($http_x_forwarded_proto = "http") {
 rewrite ^(.*)$ https://$http_host1ドル permanent;
 }
 location = /static/site.js {
 root /var/www/html/src;
 expires 1y;
 access_log off;
 add_header Cache-Control "public";
 try_files /static/$script_file =404;
 }
 location ~* ^/static/img/.+\.(png|jpg)$ {
 root /var/www/html/src;
 add_header Vary Accept;
 expires 1y;
 access_log off;
 add_header Cache-Control "public";
 try_files $uri$webp_suffix $uri =404;
 }
 location ~* ^/static/.*$
 {
 root /var/www/html/src;
 expires 1y;
 access_log off;
 add_header Cache-Control "public";
 }
 location / {
 proxy_redirect off;
 proxy_set_header X-Real-IP $remote_addr;
 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 proxy_set_header X-Forwarded-Proto $scheme;
 proxy_set_header Host $http_host;
 proxy_set_header X-NginX-Proxy true;
 proxy_set_header Connection "";
 proxy_http_version 1.1;
 proxy_pass http://node_upstream;
 }
 error_log /var/log/nginx/error.log;
 access_log /var/log/nginx/access.log;
}

Answer 1

root

The root directive is inherited. You have the same statement in the server block, and repeated in a number of location blocks. Only the first statement is necessary. See this document for details.

location ~* ^/static/.*$

This can be replaced by the prefix location:

location /static/ { ... }

The prefix location is more efficient than the regular expression location. The precedence order is different, but that does not affect your current configuration. See this document for details.

rewrite ^(.*)$ https://$http_host1ドル permanent;

You can replace this with a return statement, thus eliminating a regular expression.

return 301 https://$http_host$request_uri;

Nested location blocks

A number of statements are common to three location blocks, all of which represent URIs that begin with /static/. The expires, access_log and add_header directives are inherited.

You could restructure your locations as follows:

location /static/ {
 root /var/www/html/src;
 expires 1y;
 access_log off;
 add_header Cache-Control "public";
 location = /static/site.js {
 try_files /static/$script_file =404;
 }
 location ~* ^/static/img/.+\.(png|jpg)$ {
 add_header Vary Accept;
 add_header Cache-Control "public";
 try_files $uri$webp_suffix $uri =404;
 }
}
location / {
 ...
}

This would improve efficiency as URIs which do not begin with /static/ will not need to be checked against the regular expressions.

The add_header directive has an additional inheritance rule. See this document for details.

• Calin Leafshade: Thanks, nested location blocks is exactly the kind of thing i was looking for.