You can control access to the frontend/backend/listen sections or to the http stats by granting permissions only to authenticated users. You should create at least one userlist in the Haproxy-Add proxy-Userlist section and define users to manage permissions.
|Fill it with your userlist's name. Many independent userlists can be used to store authentication and authorization data for different customers.
|Fill it with the group's name. You can add more fields of this type to your userlist.
|Fill it with the user credentils. You can add more fields of this type to your userlist.
It is also possible to attach users to a group as a comma separated list of names preceeded by the keyword users.
How to use:
Read about creating and using userlists here.