Question about request uri args in body_filter_by_lua_block

Hello,

I am Proxying a request as follows (content_by_lua_file):

ngx.exec('/data/' .. value.id .. '.json', { myid = 'myid' })

Then I have the following filter block:

body_filter_by_lua_block {
                local args = ngx.req.get_uri_args()
                
                ngx.arg[1] = string.gsub(ngx.arg[1], '__replace-id__', args.myid)
            }

The filter block is added in a location that serves a static json file which should replace "replace-id" with args.myid string.

But it seems that args.myid is always nil, am I missing something or is it a bug?

Thanks.

Start by tracing how ngx.exec('/data/' .. value.id .. '.json', { myid = 'myid' }) passes request arguments into the location containing body_filter_by_lua_block. Inspect the behavior of ngx.req.get_uri_args() there and reproduce the nil value with the shown static JSON filter; done means the argument scope and expected behavior are established.