Simple question about rewrite_by_lua

g.veniamin · 2012-08-22T01:49:06+00:00

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Simple question about rewrite_by_lua

g.veniamin

Hello,

I have question about rewrite_by_lua.

It's my location /test, how to correct convert it to rewrite with lua scripts?

location /test {
      rewrite '^/$'                     /api?id=1       last;
      rewrite '^/topic/?$'           /api?id=1       last;
      rewrite '^/topic/([0-9]+)'    /api?id=$1     last;
      rewrite '(.*)'                    /api?id=error   last;
}

Thank you.

-- 
Regards,
Veniamin

g.veniamin

And how to use it's without proxy_pass:


    location /foo {
        rewrite_by_lua '
            res = ngx.location.capture("/memc",
                { args = { cmd = 'incr', key = ngx.var.uri } }
            )
        ';

        proxy_pass http://blah.blah.com;
    }


2012/8/21 Veniamin Gvozdikov <g.ve...@googlemail.com>:
> Hello,
>
> I have question about rewrite_by_lua.
>
> It's my location /test, how to correct convert it to rewrite with lua scripts?
>
> location /test {
>       rewrite '^/$'                     /api?id=1       last;
>       rewrite '^/topic/?$'           /api?id=1       last;
>       rewrite '^/topic/([0-9]+)'    /api?id=$1     last;
>       rewrite '(.*)'                    /api?id=error   last;
> }
>
> Thank you.
>
> --
> Regards,
> Veniamin



-- 
Regards,
Veniamin

Phone: +7 916 948 58 30
Site: http://zlonet.ru

agentzh

Hello!

On Tue, Aug 21, 2012 at 8:01 AM, Veniamin Gvozdikov wrote:
> I have question about rewrite_by_lua.
>
> It's my location /test, how to correct convert it to rewrite with lua scripts?
>
> location /test {
>       rewrite '^/$'                     /api?id=1       last;
>       rewrite '^/topic/?$'           /api?id=1       last;
>       rewrite '^/topic/([0-9]+)'    /api?id=$1     last;
>       rewrite '(.*)'                    /api?id=error   last;
> }
>

I think the location name should be / instead of /test, or it will
always rewrite to /api?id=error, no?

Here is the pure Lua version that achieve the same effect:

    location / {
        rewrite_by_lua '
            local match = ngx.re.match
            local set_args = ngx.req.set_uri_args
            local uri = ngx.var.uri

            if match(uri, "^/$", "jo") then
                set_args("id=1")
            elseif match(uri, "^/topic/?$", "jo") then
                set_args("id=1")
            else
                local m = match(uri, "^/topic/([0-9]+)", "jo")
                if m then
                    set_args("id=" .. m[1])
                else
                    set_args("id=error")
                end
            end

            return ngx.req.set_uri("/api", true)
        ';
    }

Check out ngx_lua's official documentation for more details:

    http://wiki.nginx.org/HttpLuaModule

Best regards,
-agentzh

agentzh

Hello!

On Tue, Aug 21, 2012 at 8:04 AM, Veniamin Gvozdikov wrote:
> And how to use it's without proxy_pass:
>
>     location /foo {
>         rewrite_by_lua '
>             res = ngx.location.capture("/memc",
>                 { args = { cmd = 'incr', key = ngx.var.uri } }
>             )
>         ';
>
>         proxy_pass http://blah.blah.com;
>     }
>

I'm not sure if I really understand your question. If you're asking
how to use Lua to generate responses directly in rewrite_by_lua and
bypass the proxy_pass directive completely, then you can do something
like this:

    rewrite_by_lua '
        if some_condition then
            ngx.say("My response is here! Hello, Lua!")
            ngx.exit(200)
        end
    ';

If you want to generate an error page, then do something like this:

    ngx.exit(403)

If you also want to emit a custom error page, then do something like
below instead:

    ngx.status = 403
    ngx.say("My custom 403 page here")
    ngx.exit(403)

Please see the documentation of ngx_lua for more details:

    http://wiki.nginx.org/HttpLuaModule

Best regards,
-agentzh

g.veniamin

Thank you. It's work.

2012/8/22 agentzh <age...@gmail.com>:
> Hello!
>
> On Tue, Aug 21, 2012 at 8:04 AM, Veniamin Gvozdikov wrote:
>> And how to use it's without proxy_pass:
>>
>>     location /foo {
>>         rewrite_by_lua '
>>             res = ngx.location.capture("/memc",
>>                 { args = { cmd = 'incr', key = ngx.var.uri } }
>>             )
>>         ';
>>
>>         proxy_pass http://blah.blah.com;
>>     }
>>
>
> I'm not sure if I really understand your question. If you're asking
> how to use Lua to generate responses directly in rewrite_by_lua and
> bypass the proxy_pass directive completely, then you can do something
> like this:
>
>     rewrite_by_lua '
>         if some_condition then
>             ngx.say("My response is here! Hello, Lua!")
>             ngx.exit(200)
>         end
>     ';
>
> If you want to generate an error page, then do something like this:
>
>     ngx.exit(403)
>
> If you also want to emit a custom error page, then do something like
> below instead:
>
>     ngx.status = 403
>     ngx.say("My custom 403 page here")
>     ngx.exit(403)
>
> Please see the documentation of ngx_lua for more details:
>
>     http://wiki.nginx.org/HttpLuaModule
>
> Best regards,
> -agentzh