nixpkgs/nixos/modules/virtualisation/docker.nix
Benno Fünfstück 79b4e5a8d7 docker module: fix kernel module loading
The docker module used different code for socket-activated docker daemon than for the non-socket activated daemon.
In particular, if the socket-activated daemon is used, then modprobe wasn't set up to be usable and in PATH for
the docker daemon, which resulted in a failure to start the daemon with overlayfs as storageDriver if the
`overlay` kernel module wasn't already loaded. This commit fixes that bug (which only appears if socket
activation is used), and also reduces the duplication between code paths so that it's easier to keep
both in sync in future.
2015-12-24 12:07:45 +01:00

122 lines
3.6 KiB
Nix

# Systemd services for docker.
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.virtualisation.docker;
pro = config.networking.proxy.default;
proxy_env = optionalAttrs (pro != null) { Environment = "\"http_proxy=${pro}\""; };
in
{
###### interface
options.virtualisation.docker = {
enable =
mkOption {
type = types.bool;
default = false;
description =
''
This option enables docker, a daemon that manages
linux containers. Users in the "docker" group can interact with
the daemon (e.g. to start or stop containers) using the
<command>docker</command> command line tool.
'';
};
socketActivation =
mkOption {
type = types.bool;
default = true;
description =
''
This option enables docker with socket activation. I.e. docker will
start when first called by client.
'';
};
storageDriver =
mkOption {
type = types.enum ["aufs" "btrfs" "devicemapper" "overlay" "zfs"];
default = "devicemapper";
description =
''
This option determines which Docker storage driver to use.
'';
};
extraOptions =
mkOption {
type = types.separatedString " ";
default = "";
description =
''
The extra command-line options to pass to
<command>docker</command> daemon.
'';
};
postStart =
mkOption {
type = types.lines;
default = ''
while ! [ -e /var/run/docker.sock ]; do
sleep 0.1
done
'';
description = ''
The postStart phase of the systemd service. You may need to
override this if you are passing in flags to docker which
don't cause the socket file to be created. This option is ignored
if socket activation is used.
'';
};
};
###### implementation
config = mkIf cfg.enable (mkMerge [
{ environment.systemPackages = [ pkgs.docker ];
users.extraGroups.docker.gid = config.ids.gids.docker;
systemd.services.docker = {
description = "Docker Application Container Engine";
wantedBy = optional (!cfg.socketActivation) "multi-user.target";
after = [ "network.target" ] ++ (optional cfg.socketActivation "docker.socket") ;
requires = optional cfg.socketActivation "docker.socket";
serviceConfig = {
ExecStart = "${pkgs.docker}/bin/docker daemon --group=docker --storage-driver=${cfg.storageDriver} ${optionalString cfg.socketActivation "--host=fd://"} ${cfg.extraOptions}";
# I'm not sure if that limits aren't too high, but it's what
# goes in config bundled with docker itself
LimitNOFILE = 1048576;
LimitNPROC = 1048576;
} // proxy_env;
path = [ pkgs.kmod ] ++ (optional (cfg.storageDriver == "zfs") pkgs.zfs);
environment.MODULE_DIR = "/run/current-system/kernel-modules/lib/modules";
postStart = if cfg.socketActivation then "" else cfg.postStart;
# Presumably some containers are running we don't want to interrupt
restartIfChanged = false;
};
}
(mkIf cfg.socketActivation {
systemd.sockets.docker = {
description = "Docker Socket for the API";
wantedBy = [ "sockets.target" ];
socketConfig = {
ListenStream = "/var/run/docker.sock";
SocketMode = "0660";
SocketUser = "root";
SocketGroup = "docker";
};
};
})
]);
}