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Nginx matches a specific word in a location

I'm having a problem defining a specific word in the nginx $ request_body variable. I want a proxy pass if the body request has a special word in it,

So my approach is this:

location ~ \.php$ { if ($request_body ~* (.*)) { proxy_pass http://test.proxy; break; } # other case... }

This is consistent with everything, and the if statement works, but if I somehow change the regex, I can't get hit.

So my question is:

How do I determine the correct regex expression in nginx to match, for example, "target"?

Thanks in advance!

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2 answers

There are a number of problems in your code.

  • "($ request_body ~ * (. *))" never matches anything as indicated by someone else, and therefore the "other case" is always the result

  • More importantly, it uses "proxy_pass" with "if", which is classically evil. http://wiki.nginx.org/IfIsEvil .

To get what you want, use the third-party module ngx_lua (v0.3.1rc24 and higher) ...

 location ~ \.php$ { rewrite_by_lua ' ngx.req.read_body() local match = ngx.re.match(ngx.var.request_body, "target") if match then ngx.exec("@proxy"); else ngx.exec("@other_case"); end '; } location @proxy { # test.proxy stuff ... } location @other_case { # other_case stuff ... }

You can get ngx_lua at https://github.com/chaoslawful/lua-nginx-module/tags .

PS. Keep in mind that rewrite by lua is always executed after the nginx rewrite directives, so if you put any such directives in another case, they will be executed first and you will get funnies.

You must put all your rewrites in correspondence using the lua context to get consistent results. This is the reason that "if..sese..end" is for a "different case."

You may need this longer version.

 location ~ \.php$ { rewrite_by_lua ' --request body only available for POST requests if ngx.var.request_method == "POST" -- Try to read in request body ngx.req.read_body() -- Try to load request body data to a variable local req_body = ngx.req.get_body_data() if not req_body then -- If empty, try to get buffered file name local req_body_file_name = ngx.req.get_body_file() --[[If the file had been buffered, open it, read contents to our variable and close]] if req_body_file_name then file = io.open(req_body_file_name) req_body = file:read("*a") file:close() end end -- If we got request body data, test for our text if req_body then local match = ngx.re.match(req_body, "target") if match then -- If we got a match, redirect to @proxy ngx.exec("@proxy") else -- If no match, redirect to @other_case ngx.exec("@other_case") end end else -- Pass non "POST" requests to @other_case ngx.exec("@other_case") end '; }
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Leadership:

Note: for curly braces ({and}), since they are used both in regular expressions and to control the block, to avoid conflicts, regular expressions with curly braces must be enclosed in double quotes (or single quotes).

try

 if ($request_body ~* "(.*)")

Other comments: Code .* Matches all. Instead, I would use \w since the Perl regex is available.

Your current if -clause is always incorrect, so it doesn’t need the correct result.

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