rgw: allow beast frontend to listen on specific IP address

[zhouyuan]

This patch allows the beast frontend to listen on a specific
IP address rather than *. e.g., with below configuration:

rgw frontends = beast port=1.2.3.4:8080

rgw server will listen on 1.2.3.4 only.

Signed-off-by: Yuan Zhou yuan.zhou@intel.com

[cbodley]

very cool, thank you. i think we'd be better of adding a separate config key like "ip" or "addr" to the frontend config though, instead of extending "port" this way

it would also be good to consider whether the civetweb frontend could take advantage of this feature too

and whatever we do, we'll need to document it clearly. i don't see anything at all about rgw_frontends in https://github.com/ceph/ceph/blob/master/doc/radosgw/config-ref.rst, but that's where it would go - i can work on that separately

[zhouyuan]

@cbodley yes, the civetweb frontend support this configuration already, actually I find the missing gap when doing some tests on a existing RGW cluster with civetweb frontend.

[cbodley]

posting for my reference: http://tracker.ceph.com/issues/13670 is the doc bug for rgw_frontends

[zhouyuan]

@cbodley I'm trying to add separate config key "addr" and "port "here, do you think we should change this for civetweb/fastcgi frontend also? To avoid breaking some existing cluster I guess we may should also accept the "port" configuration?

[cbodley]

@zhouyuan thanks, i didn't realize that civetweb uses "port" for the address as well (https://github.com/ceph/civetweb/blob/wip-listen4/src/civetweb.c#L10293-L10299). let's leave that how it as, and use the new "addr" config for beast only - we'll just need to document that clearly so we don't confuse people on upgrade

[cbodley]

thinking about this more, i actually prefer civetweb's approach here - that syntax allows you to specify multiple ports, like 80+443s, each of which could specify a bind address. if we separate the addr configuration from the port, you'd have to run multiple frontends (ie rgw_frontends = beast addr=127.0.0.1 port=8000, beast port=80) to accomplish that

[cbodley]

according to the docs for from_string(), it's deprecated in favor of make_address() - can you use the overload that takes string_view and avoid the use of vector/string? something like:

  tcp::address addr; // default to 'any'
  boost::string_view input = port_str;
  auto colon = input.find(':');
  if (colon != input.npos) {
    boost::system::error_code ec;
    addr = boost::asio::ip::address::make_address(input.substr(0, colon), ec);
    if (ec) {
      lderr(ctx()) << "failed to parse address '" << port_str << "': " << ec.message() << dendl;
      return -ec.value();
    }
  }
  tcp::endpoint ep = {addr, port};

then eventually we can extend the frontend to listen on multiple sockets

[cbodley]

see #20058 for first draft of frontend configuration docs

[cbodley]

thanks, this looks good! i created a ticket to track this for backport, could you please add Fixes: http://tracker.ceph.com/issues/22778 to your commit message?

[cbodley]

thanks @zhouyuan! i've built on this work to add support for multiple endpoints in #20188