HAProxy Enterprise Documentation 2.2r1
Inline ACLs
Although you can define an ACL on its own by using the acl
directive, in which case it can be referenced on another line by name:
frontend www bind :80 acl api_url path_beg
/api/use_backend api_servers if api_url backend api_servers server s1 192.168.50.20:80
You can also declare the ACL inline by surrounding the expression with curly braces:
frontend www bind :80 use_backend api_servers if { path_beg
/api/} backend api_servers server s1 192.168.50.20:80
Next up
ACL Reference