allow-dup-ip is ignored if server has resolvers and backend has default-server

[sigint2]

Detailed Description of the Problem

Hi -- I noticed that allow-dup-ip is ignored when:

• a server has a resolvers associated with it ( either explicitly, or via a default ), AND
• the backend that the server belongs to has a default-server line in it.

Expected Behavior

That the global default-server resolve-opts are not reset by a default-server in a backend.

Steps to Reproduce the Behavior

The following config should illustrate the behavior:

• the backend level default-server backup is applied to all servers
• the global defaults weight 42 is applied to all servers.
• the global defaults field resolve-opts allow-dup-ip is not applied ( stats page shows server app2 in maintenance mode )

resolvers test
    parse-resolv-conf

defaults
    mode tcp
    default-server resolvers test resolve-opts allow-dup-ip weight 42

frontend foo
    bind 127.0.0.1:9999
    use_backend bar

backend bar
    default-server backup
    server app1 localhost:9999 no-check
    server app2 localhost:9990 no-check

the weight of the servers is overridden with 42

Do you have any idea what may have caused this?

In src/server.c the resolve opts seem to get reset to hard-coded values when the above conditions are met, the other option that is reset is resolve-prefer .

    else {
        *srv = newsrv = &curproxy->defsrv;
        *cur_arg = 1;
        newsrv->resolv_opts.family_prio = AF_INET6;
        newsrv->resolv_opts.accept_duplicate_ip = 0;
    }

Do you have an idea how to solve the issue?

No response

What is your configuration?

resolvers test
    parse-resolv-conf

defaults
    mode tcp
    default-server resolvers test resolve-opts allow-dup-ip weight 42

frontend foo
    bind 127.0.0.1:9999
    use_backend bar

backend bar
    default-server backup
    server app1 localhost:9999 no-check
    server app2 localhost:9990 no-check

Output of haproxy -vv

( cannot paste ) -- tested on standard builds of 2.6.15, and 3.0-dev10

Last Outputs and Backtraces

No response

Additional Information

No response

[capflam]

Indeed, it seems you're right. There is no reason to reset resolve options when a default-server line is parsed.

[capflam]

Fixed now, thanks !