modularize address lookup

    return margo_addr_lookup_retry(daemon_addr);

}

/*

 * Get the URI of a given hostname.

 *

 * This URI is to be used for margo lookup function.

 */

std::string get_uri_from_hostname(const std::string& hostname) {

    auto host = hostname + HOSTNAME_SUFFIX;

    // get the ip address from /etc/hosts which is mapped to the sys_hostfile map

    if (CTX->fs_conf()->sys_hostfile.count(host) == 1) {

        host = CTX->fs_conf()->sys_hostfile.at(host);

    }

    return fmt::format("{}://{}:{}", RPC_PROTOCOL, host, CTX->fs_conf()->rpc_port);

}

bool lookup_all_hosts() {

    rpc_addresses = std::make_unique<std::unordered_map<uint64_t, hg_addr_t>>();

    vector<uint64_t> hosts(CTX->fs_conf()->host_size);

    ::mt19937 g(rd()); // seed the random generator

    ::shuffle(hosts.begin(), hosts.end(), g); // Shuffle hosts vector

    // lookup addresses and put abstract server addresses into rpc_addresses

    hg_addr_t remote_addr = HG_ADDR_NULL;

    std::string remote_uri;

    for (auto& host : hosts) {

        auto hostname = CTX->fs_conf()->hosts.at(host) + HOSTNAME_SUFFIX;

        // get the ip address from /etc/hosts which is mapped to the sys_hostfile map

        if (CTX->fs_conf()->sys_hostfile.count(hostname) == 1) {

            auto remote_ip = CTX->fs_conf()->sys_hostfile.at(hostname);

            remote_uri = RPC_PROTOCOL + "://"s + remote_ip + ":"s + CTX->fs_conf()->rpc_port;

        } else {

            // fallback hostname to use for lookup

            remote_uri = RPC_PROTOCOL + "://"s + hostname + ":"s + CTX->fs_conf()->rpc_port;

        }

        remote_addr = margo_addr_lookup_retry(remote_uri);

        auto hostname = CTX->fs_conf()->hosts.at(host);

        auto uri = get_uri_from_hostname(hostname);

        auto remote_addr = margo_addr_lookup_retry(uri);

        if (remote_addr == HG_ADDR_NULL) {

            CTX->log()->error("{}() Failed to lookup address {}", __func__, remote_uri);

            CTX->log()->error("{}() Failed to lookup address {}", __func__, uri);

            return false;

        }

        CTX->log()->trace("generated remote_addr {} for hostname {} with rpc_port {}",

                remote_uri, hostname, CTX->fs_conf()->rpc_port);

        CTX->log()->trace("{}() Successful address lookup for '{}'", __func__, uri);

        rpc_addresses->insert(make_pair(host, remote_addr));

    }

    return true;