nixpkgs/nixos/modules/config/networking.nix
Jan Malakhovski 1ece5041a4 nixos/networking: simplify /etc/hosts generation, add asserts
Since `networking.hosts` is properly typed all of that magic `/etc/hosts` generator
does can be dropped. People that disagree with the value of `networking.hosts` can
simply `mkForce`.
2018-10-02 23:58:35 +00:00

315 lines
10 KiB
Nix

# /etc files related to networking, such as /etc/services.
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.networking;
dnsmasqResolve = config.services.dnsmasq.enable &&
config.services.dnsmasq.resolveLocalQueries;
hasLocalResolver = config.services.bind.enable ||
config.services.unbound.enable ||
dnsmasqResolve;
resolvconfOptions = cfg.resolvconfOptions
++ optional cfg.dnsSingleRequest "single-request"
++ optional cfg.dnsExtensionMechanism "edns0";
localhostMapped4 = cfg.hosts ? "127.0.0.1" && elem "localhost" cfg.hosts."127.0.0.1";
localhostMapped6 = cfg.hosts ? "::1" && elem "localhost" cfg.hosts."::1";
localhostMultiple = any (elem "localhost") (attrValues (removeAttrs cfg.hosts [ "127.0.0.1" "::1" ]));
in
{
options = {
networking.hosts = lib.mkOption {
type = types.attrsOf (types.listOf types.str);
example = literalExample ''
{
"127.0.0.1" = [ "foo.bar.baz" ];
"192.168.0.2" = [ "fileserver.local" "nameserver.local" ];
};
'';
description = ''
Locally defined maps of hostnames to IP addresses.
'';
};
networking.extraHosts = lib.mkOption {
type = types.lines;
default = "";
example = "192.168.0.1 lanlocalhost";
description = ''
Additional verbatim entries to be appended to <filename>/etc/hosts</filename>.
'';
};
networking.hostConf = lib.mkOption {
type = types.lines;
default = "multi on";
example = ''
multi on
reorder on
trim lan
'';
description = ''
The contents of <filename>/etc/host.conf</filename>. See also <citerefentry><refentrytitle>host.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
'';
};
networking.dnsSingleRequest = lib.mkOption {
type = types.bool;
default = false;
description = ''
Recent versions of glibc will issue both ipv4 (A) and ipv6 (AAAA)
address queries at the same time, from the same port. Sometimes upstream
routers will systemically drop the ipv4 queries. The symptom of this problem is
that 'getent hosts example.com' only returns ipv6 (or perhaps only ipv4) addresses. The
workaround for this is to specify the option 'single-request' in
/etc/resolv.conf. This option enables that.
'';
};
networking.dnsExtensionMechanism = lib.mkOption {
type = types.bool;
default = true;
description = ''
Enable the <code>edns0</code> option in <filename>resolv.conf</filename>. With
that option set, <code>glibc</code> supports use of the extension mechanisms for
DNS (EDNS) specified in RFC 2671. The most popular user of that feature is DNSSEC,
which does not work without it.
'';
};
networking.extraResolvconfConf = lib.mkOption {
type = types.lines;
default = "";
example = "libc=NO";
description = ''
Extra configuration to append to <filename>resolvconf.conf</filename>.
'';
};
networking.resolvconfOptions = lib.mkOption {
type = types.listOf types.str;
default = [];
example = [ "ndots:1" "rotate" ];
description = ''
Set the options in <filename>/etc/resolv.conf</filename>.
'';
};
networking.timeServers = mkOption {
default = [
"0.nixos.pool.ntp.org"
"1.nixos.pool.ntp.org"
"2.nixos.pool.ntp.org"
"3.nixos.pool.ntp.org"
];
description = ''
The set of NTP servers from which to synchronise.
'';
};
networking.proxy = {
default = lib.mkOption {
type = types.nullOr types.str;
default = null;
description = ''
This option specifies the default value for httpProxy, httpsProxy, ftpProxy and rsyncProxy.
'';
example = "http://127.0.0.1:3128";
};
httpProxy = lib.mkOption {
type = types.nullOr types.str;
default = cfg.proxy.default;
description = ''
This option specifies the http_proxy environment variable.
'';
example = "http://127.0.0.1:3128";
};
httpsProxy = lib.mkOption {
type = types.nullOr types.str;
default = cfg.proxy.default;
description = ''
This option specifies the https_proxy environment variable.
'';
example = "http://127.0.0.1:3128";
};
ftpProxy = lib.mkOption {
type = types.nullOr types.str;
default = cfg.proxy.default;
description = ''
This option specifies the ftp_proxy environment variable.
'';
example = "http://127.0.0.1:3128";
};
rsyncProxy = lib.mkOption {
type = types.nullOr types.str;
default = cfg.proxy.default;
description = ''
This option specifies the rsync_proxy environment variable.
'';
example = "http://127.0.0.1:3128";
};
allProxy = lib.mkOption {
type = types.nullOr types.str;
default = cfg.proxy.default;
description = ''
This option specifies the all_proxy environment variable.
'';
example = "http://127.0.0.1:3128";
};
noProxy = lib.mkOption {
type = types.nullOr types.str;
default = null;
description = ''
This option specifies the no_proxy environment variable.
If a default proxy is used and noProxy is null,
then noProxy will be set to 127.0.0.1,localhost.
'';
example = "127.0.0.1,localhost,.localdomain";
};
envVars = lib.mkOption {
type = types.attrs;
internal = true;
default = {};
description = ''
Environment variables used for the network proxy.
'';
};
};
};
config = {
assertions = [{
assertion = localhostMapped4;
message = ''`networking.hosts` doesn't map "127.0.0.1" to "localhost"'';
} {
assertion = !cfg.enableIPv6 || localhostMapped6;
message = ''`networking.hosts` doesn't map "::1" to "localhost"'';
} {
assertion = !localhostMultiple;
message = ''
`networking.hosts` maps "localhost" to something other than "127.0.0.1"
or "::1". This will break some applications. Please use
`networking.extraHosts` if you really want to add such a mapping.
'';
}];
networking.hosts = {
"127.0.0.1" = [ "localhost" ];
} // optionalAttrs cfg.enableIPv6 {
"::1" = [ "localhost" ];
};
environment.etc =
{ # /etc/services: TCP/UDP port assignments.
"services".source = pkgs.iana-etc + "/etc/services";
# /etc/protocols: IP protocol numbers.
"protocols".source = pkgs.iana-etc + "/etc/protocols";
# /etc/rpc: RPC program numbers.
"rpc".source = pkgs.glibc.out + "/etc/rpc";
# /etc/hosts: Hostname-to-IP mappings.
"hosts".text = let
oneToString = set: ip: ip + " " + concatStringsSep " " set.${ip};
allToString = set: concatMapStringsSep "\n" (oneToString set) (attrNames set);
in ''
${allToString cfg.hosts}
${cfg.extraHosts}
'';
# /etc/host.conf: resolver configuration file
"host.conf".text = cfg.hostConf;
# /etc/resolvconf.conf: Configuration for openresolv.
"resolvconf.conf".text =
''
# This is the default, but we must set it here to prevent
# a collision with an apparently unrelated environment
# variable with the same name exported by dhcpcd.
interface_order='lo lo[0-9]*'
'' + optionalString (length resolvconfOptions > 0) ''
# Options as described in resolv.conf(5)
resolv_conf_options='${concatStringsSep " " resolvconfOptions}'
'' + optionalString hasLocalResolver ''
# This hosts runs a full-blown DNS resolver.
name_servers='127.0.0.1'
'' + optionalString dnsmasqResolve ''
dnsmasq_conf=/etc/dnsmasq-conf.conf
dnsmasq_resolv=/etc/dnsmasq-resolv.conf
'' + cfg.extraResolvconfConf + ''
'';
} // optionalAttrs config.services.resolved.enable {
# symlink the static version of resolv.conf as recommended by upstream:
# https://www.freedesktop.org/software/systemd/man/systemd-resolved.html#/etc/resolv.conf
"resolv.conf".source = "${pkgs.systemd}/lib/systemd/resolv.conf";
} // optionalAttrs (config.services.resolved.enable && dnsmasqResolve) {
"dnsmasq-resolv.conf".source = "/run/systemd/resolve/resolv.conf";
};
networking.proxy.envVars =
optionalAttrs (cfg.proxy.default != null) {
# other options already fallback to proxy.default
no_proxy = "127.0.0.1,localhost";
} // optionalAttrs (cfg.proxy.httpProxy != null) {
http_proxy = cfg.proxy.httpProxy;
} // optionalAttrs (cfg.proxy.httpsProxy != null) {
https_proxy = cfg.proxy.httpsProxy;
} // optionalAttrs (cfg.proxy.rsyncProxy != null) {
rsync_proxy = cfg.proxy.rsyncProxy;
} // optionalAttrs (cfg.proxy.ftpProxy != null) {
ftp_proxy = cfg.proxy.ftpProxy;
} // optionalAttrs (cfg.proxy.allProxy != null) {
all_proxy = cfg.proxy.allProxy;
} // optionalAttrs (cfg.proxy.noProxy != null) {
no_proxy = cfg.proxy.noProxy;
};
# Install the proxy environment variables
environment.sessionVariables = cfg.proxy.envVars;
# This is needed when /etc/resolv.conf is being overriden by networkd
# and other configurations. If the file is destroyed by an environment
# activation then it must be rebuilt so that applications which interface
# with /etc/resolv.conf directly don't break.
system.activationScripts.resolvconf = stringAfter [ "etc" "specialfs" "var" ]
''
# Systemd resolved controls its own resolv.conf
rm -f /run/resolvconf/interfaces/systemd
${optionalString config.services.resolved.enable ''
rm -rf /run/resolvconf/interfaces
mkdir -p /run/resolvconf/interfaces
ln -s /run/systemd/resolve/resolv.conf /run/resolvconf/interfaces/systemd
''}
# Make sure resolv.conf is up to date if not managed manually or by systemd
${optionalString (!config.environment.etc?"resolv.conf") ''
${pkgs.openresolv}/bin/resolvconf -u
''}
'';
};
}