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  3. varnish-modules
  4. vmod_bodyaccess(3)

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VMOD_BODYACCESS(3) VMOD_BODYACCESS(3)

NAME

vmod_bodyaccess - Varnish Module for request body access

SYNOPSIS

import bodyaccess [as name] [from "path"]
INT rematch_req_body(REGEX re)
VOID hash_req_body()
INT len_req_body()
VOID log_req_body(STRING prefix, INT length)


DESCRIPTION

Varnish module that lets you access the request body.

VCL example:

vcl 4.0;
import std;
import bodyaccess;
backend default { .host = "192.0.2.11"; .port = "8080"; }
sub vcl_recv {


        if (req.method == "POST") {


                set req.http.x-method = req.method;


                if (std.cache_req_body(110KB)) {


                        set req.http.x-len = bodyaccess.len_req_body();


                        set req.http.x-re = bodyaccess.rematch_req_body("Regex");


                        bodyaccess.log_req_body("PREFIX:", 3);


                }


        }
return(hash);
}
sub vcl_hash {


        bodyaccess.hash_req_body();


        return (lookup);
}
sub vcl_backend_fetch {


        set bereq.method = bereq.http.x-method;
}
sub vcl_deliver {


        set resp.http.x-len = req.http.x-len;


        set resp.http.x-re = req.http.x-re;
}


N.B. The request body must be retrieved before doing any operations on it. It can be buffered using the cache_req_body() function from libvmod_std.

These functions applies only to standard REST methods. Caching is not allowed on PUT requests.

INT rematch_req_body(REGEX re)

Returns -1 if an error occurrs. Returns 0 if the request body doesn't contain the string re. Returns 1 if the request body contains the string re.

Note that the comparison is case sensitive and the request body must be buffered.

| std.cache_req_body(1KB);
|
| if (bodyaccess.rematch_req_body("FOO") == 1) {
|    std.log("is true");
| }



VOID hash_req_body()

Adds available request body bytes to the lookup hash key. Note that this function can only be used in vcl_hash and the request body must be buffered.

| sub vcl_recv {
|     std.cache_req_body(1KB);
| }
|
| sub vcl_hash{
|     bodyaccess.hash_req_body();
| }



INT len_req_body()

Returns the request body length or -1 if an error occurs.

Note that the request body must be buffered.

| std.cache_req_body(1KB);
| set req.http.x-len = bodyaccess.len_req_body();



VOID log_req_body(STRING prefix="", INT length=200)

Log the request body to the VSL, making it available for other components. When logging, it takes an optional prefix and a max line length, so the body could be split up across multiple lines as there is a limit to how large a single line can be.

| std.cache_req_body(1KB);
| bodyaccess.log_req_body("PREFIX:", 3);