Nginx rewrite: last & break

[Maxim Dounin]

Hello!

On Sat, Oct 22, 2011 at 02:04:21PM +0300, Nginx User wrote:

> On 22 October 2011 06:30, Ryan Chan <ryanchan404 at gmail.com> wrote:
> > Anyone would like to do a quick summary for the issue?
> 
> Minaev's answer in the serverfault link you provided is the clearest
> explanation I have seen to date of this.
> 
> To paraphrase, he says, within a location block, when you use "last"
> the rewrites are stopped and a new subrequest is generated which will

Just a side note: "subrequest" is incorrect term here.

> take all all locations into account. When you use "break" the rewrites
> are stopped and processing continued within the location you are in.
> 
> Adding Maxim's statement above into account, outside a location block,
> "break" behaves just like "last" does since there are no location
> directives to run here.
> 
> Someone just needs to update the docs if this is correct.

Reading rewrite module docs carefully enough will tell basically 
the same:

...
If the URI changed as a result of the execution of directives 
inside location, then location is again determined for the new 
URI.  This cycle can be repeated up to 10 times, after which Nginx 
returns a 500 error.
...

...
Example:

    rewrite  ^(/download/.*)/media/(.*)\..*$  $1/mp3/$2.mp3  last;
    rewrite  ^(/download/.*)/audio/(.*)\..*$  $1/mp3/$2.ra   last;
    return   403;

But if we place these directives in location /download/, then it 
is necessary to replace flag "last" by "break", otherwise Nginx 
will hit the 10 cycle limit and return error 500:

    location /download/ {
        rewrite  ^(/download/.*)/media/(.*)\..*$  $1/mp3/$2.mp3  break;
        rewrite  ^(/download/.*)/audio/(.*)\..*$  $1/mp3/$2.ra   break;
        return   403;
    }
...

The translation though looks awful and needs re-translation; 
additionally, it was already polluted with user comments, and this 
doesn't improve readability either.

Maxim Dounin