Nginx url rewriting: difference between break and last

nginxrewrite

I don't understand the difference between break and last (flags of rewrite). The documentation is rather abstruse. I've tried to switch between the two in some of my configs, but I couldn't spot any difference in behavior. Can someone please explain these flags in more detail? Preferably with an example that shows different behavior when flipping one flag to another.

Best Answer

You may have different sets of rewrite rules for different locations. When rewrite module meets last, it stops processing the current set and the rewritten request is passed once again to find the appropriate location (and the new set of rewriting rules). If the rule ends with break, the rewriting also stops, but the rewritten request is not passed to another location.

That is, if there are two locations: loc1 and loc2, and there's a rewriting rule in loc1 that changes loc1 to loc2 AND ends with last, the request will be rewritten and passed to location loc2. If the rule ends with break, it will belong to location loc1.

Related Solutions

Nginx reverse proxy + URL rewrite

Any redirect to localhost doesn't make sense from a remote system (e.g. client's Web browser). So the rewrite flags permanent (301) or redirect (302) are not usable in your case.

Please try following setup using a transparent rewrite rule:

location  /foo {
  rewrite /foo/(.*) /$1  break;
  proxy_pass         http://localhost:3200;
  proxy_redirect     off;
  proxy_set_header   Host $host;
}

Use curl -i to test your rewrites. A very subtle change to the rule can cause nginx to perform a redirect.

Nginx – Rewriting (not redirecting) a URL in Nginx

We have several clients that have it set up so they retain control over their own DNS, as some of them only have subdomains that point at us. We are using nginx as a load balancer that also handles redirects, and we have our redirects in the default vhost file (00default). Nothing too complex, it works quite well for us:

if ($host ~* "^ourdomain.com$") {
  rewrite ^(.*)$ http://www.ourdomain.com$1 permanent;
}

if ($host ~* "^subdomain.otherdomain.com$") {
  rewrite ^(.*)$ https://ourdomain.com$1 permanent;
}

if ($uri !~* (/option/.*|/simple/.*|/embed/.*|/mini/.*|/someOtherOption\.action.*|/otherOption\.action.*|/file/[0-9a-zA-Z]+/html5.*|/file/[0-9a-zA-Z]+/html5mobile.*|/thumbnail/.*) ) {
  set $cname_match "N";
}

if ($host !~* "(.*\.)?ourdomain\.com|videos\.yetanotherdomain\.com") {
  set $cname_match "${cname_match}N";
}
if ($cname_match = "NN") { rewrite ^.*$ http://www.ourdomain.com/; }

if ($uri !~* (/thumbnail_.*|/vcomments/.*|/onethmb.gif$|/crossdomain.xml$|/otherthmb[0-9]+.gif$)) {
  set $thumb_redirect "Y";
}
    if ($host ~* "^(cdn-)?thumbs\.ourdomain\.com") {
      set $thumb_redirect "${thumb_redirect}Y";
    }
    if ($thumb_redirect = "YY") { rewrite ^.*$ http://www.ourdomain.com/ permanent; }

 location / {
   proxy_pass      http://ourdomain_apache_pool;
   error_page 404 @fallback404;
   error_page 403 @fallback403;
 }
 # redirects
 location /learn-more {
   rewrite /learn-more/? http://www.ourdomain.com/features permanent;
 }
 # help
 location ~* ^/help/zendesk/*.*$ {
   proxy_pass      http://ourdomain_ruby_pool;   
 }
 location ~* ^/help/*.* {
   rewrite ^/(.*) http://support.ourdomain.com permanent;
 }

It does seem to me that you could take one of the above rewrite rules, like:

if ($host ~* "^subdomain.otherdomain.com$") {
  rewrite ^(.*)$ https://ourdomain.com$1 permanent;
}

and just have them point the DNS to their domain at your server, then rewrite it as you pleased.

Best Answer

Related Solutions

Nginx reverse proxy + URL rewrite

Nginx – Rewriting (not redirecting) a URL in Nginx

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