$arg_s:event:id does not work

[rcosnita@…]

I try to set a variable in nginx configuration which holds the value of the query parameter: s:event:id. Unfortunately, it does not work. Below you can find a sample location from my configuration file:

location /test-error {

set $sid $arg_s:event:sid;

return 200 $sid;

}

sid variable holds :event:sid instead of the query parameter value. Below you can find a curl statement for testing this:

curl -v ​http://127.0.0.1:8080/test-error?s:event:sid=123x46xx

[rcosnita@…]

I've just reproduced the bug in the latest nginx relase: 1.13.0. The commit number I've used for building the nginx from is 0cb7be3c715fd6b85227610c654c9b8f6f7ae666.

[rcosnita@…]

I know colon (:) is a reserved character but I think there are many cases where people are using it in the query parameter name (even though they shouldn't).

[rcosnita@…]

Here is a possible workaround for the problem:

location /test-error {

set $sid "";

if ($args ~* "s:event:sid=(.*)[&]?") {

set $sid $1;

}

return 200 $sid;

}

[Maxim Dounin]

Variable names in nginx can only include alphabetical characters, numbers, and "_" ([a-zA-Z0-9_]), so nginx sees $arg_s:event:sid in your example as the $arg_s variable and the :event:sid string. There are no plans to changes this. Using the $args variable if you want to access arguments with non-trivial names is a way to go.