HAPROXY: Get the equivalent of a fullbase fetch, that is the concatenation of the host header, the path, and the query string

haproxy.cfg

# Build a new (internal) header containing the required full-base data
# Unfortunately, we can't use variables here since they can't be used to concat data
http-request set-header X-Full-Base %[base]
http-request set-header X-Full-Base %[base]?%[query] if { query -m found }

http-request deny if { req.hdr(X-Full-Base),map(/path/to/url_list.txt) -m found }

# cleanup
http-request del-header X-Full-Base

# you can replace the first 2 lines with this one

http-request set-header X-Full-Base %[base]%HQ