net: Improve IPv6 support

[BenPope]

Note

This seems to break metrics_reporter:

TRACE 2022-09-28 21:36:26,461 [shard  0] dns_resolver - Release socket 1 -> 2
  | test_cluster_rpunit: /v/build/v_deps_build/seastar-prefix/src/seastar/include/seastar/core/future.hh:648: void seastar::future_state<seastar::internal::monostate>::set(A &&...) [T = seastar::internal::monostate, A = <>]: Assertion `_u.st == state::future' failed.

Cover letter

Instead of insisting that IP addresses are IPv4 by default, let the implementation figure it out.

This allows to bind addresses to :: or ::1, for example:

pandaproxy:
  pandaproxy_api:
    - # curl https://[::1]:18082/topics
      address: "::1"
      port: 18082
      name: ipv6_listener

Notes for Reviewer

I'd like to have included tests, but not all systems have IPv6 enabled. I ran this locally:

#include "net/dns.h"

#include "net/unresolved_address.h"

#include <seastar/testing/thread_test_case.hh>

#include <boost/test/tools/old/interface.hpp>

SEASTAR_THREAD_TEST_CASE(dns_resolve) {
    net::unresolved_address ipv4_addr("127.0.0.1", 19092);
    auto ipv4 = net::resolve_dns(ipv4_addr).get();

    BOOST_REQUIRE_EQUAL(ipv4.port(), ipv4_addr.port());
    BOOST_REQUIRE_EQUAL(
      ipv4.family(), static_cast<short>(ss::net::inet_address::family::INET));
    BOOST_REQUIRE(ipv4.addr().is_ipv4());
    BOOST_REQUIRE_EQUAL(ipv4.addr().hostname().get(), "localhost");

    net::unresolved_address ipv6_addr("::1", 19093);
    auto ipv6 = net::resolve_dns(ipv6_addr).get();
    BOOST_REQUIRE_EQUAL(ipv6.port(), ipv6_addr.port());
    BOOST_REQUIRE_EQUAL(
      ipv6.family(), static_cast<short>(ss::net::inet_address::family::INET6));
    BOOST_REQUIRE(ipv6.addr().is_ipv6());
    BOOST_REQUIRE_EQUAL(ipv6.addr().hostname().get(), "ip6-localhost");

    net::unresolved_address ipv6_addr2("ip6-localhost", 19094);
    ipv6 = net::resolve_dns(ipv6_addr2).get();
    BOOST_REQUIRE_EQUAL(ipv6.port(), ipv6_addr2.port());
    BOOST_REQUIRE_EQUAL(
      ipv6.family(), static_cast<short>(ss::net::inet_address::family::INET6));
    BOOST_REQUIRE(ipv6.addr().is_ipv6());
    BOOST_REQUIRE_EQUAL(ipv6.addr().hostname().get(), "ip6-localhost");
}

Signed-off-by: Ben Pope [email protected]

Fixes #ISSUE-NUMBER, Fixes #ISSUE-NUMBER, ...

Backport Required

• [ ] not a bug fix
• [ ] issue does not exist in previous branches
• [ ] papercut/not impactful enough to backport
• [x] v22.3.x
• [x] v22.2.x
• [x] v22.1.x
• [x] v21.11.x

UX changes

• none

Release notes

• Improve support for IPv6.