connect_tcp_by_name.hpp File Reference

Detailed Description

Establishes a TCP connection to the given host and port using DNS resolution via the provided clients::dns::Resolver.

Definition in file connect_tcp_by_name.hpp.

Go to the source code of this file.

#include <cstdint>
#include <string>
#include <userver/clients/dns/resolver_fwd.hpp>
#include <userver/engine/deadline.hpp>
#include <userver/engine/io/socket.hpp>

Functions
engine::io::Socket	net::ConnectTcpByName (const std::string &host, std::uint16_t port, clients::dns::Resolver &resolver, engine::Deadline deadline)
	Establishes a TCP connection to the given host and port using DNS resolution via the provided clients::dns::Resolver.

Function Documentation

ConnectTcpByName()

engine::io::Socket net::ConnectTcpByName	(	const std::string &	host,
		std::uint16_t	port,
		clients::dns::Resolver &	resolver,
		engine::Deadline	deadline )

Establishes a TCP connection to the given host and port using DNS resolution via the provided clients::dns::Resolver.

Resolves the host name using resolver (which may use cache, /etc/hosts, and network DNS), then tries to connect to each resolved address in turn. The first successful connection is returned. TCP_NODELAY is set on the socket.

Parameters

host	DNS name or IP address to connect to (e.g. "localhost", "example.com", "127.0.0.1").
port	TCP port number.
resolver	DNS resolver instance (e.g. from clients::dns::Component).
deadline	Maximum time allowed for the whole operation (resolution + connection). Same deadline is used for both resolve and connect steps.

Returns

A connected TCP socket.

Exceptions

clients::dns::ResolverException	or clients::dns::NotResolvedException if the host name cannot be resolved.
engine::io::IoException	if connection to all resolved addresses fails (e.g. connection refused, timeout).

Note

Without a Resolver (e.g. in non-component code) use net::blocking::ConnectTcpByName.

    auto socket = net::ConnectTcpByName("localhost", listener.Port(), resolver, deadline);