lix/docker.nix
2023-05-16 14:35:31 +02:00

304 lines
8 KiB
Nix

{ pkgs ? import <nixpkgs> { }
, lib ? pkgs.lib
, name ? "nix"
, tag ? "latest"
, bundleNixpkgs ? true
, channelName ? "nixpkgs"
, channelURL ? "https://nixos.org/channels/nixpkgs-unstable"
, extraPkgs ? []
, maxLayers ? 100
, nixConf ? {}
, flake-registry ? null
}:
let
defaultPkgs = with pkgs; [
nix
bashInteractive
coreutils-full
gnutar
gzip
gnugrep
which
curl
less
wget
man
cacert.out
findutils
iana-etc
git
openssh
] ++ extraPkgs;
users = {
root = {
uid = 0;
shell = "${pkgs.bashInteractive}/bin/bash";
home = "/root";
gid = 0;
groups = [ "root" ];
description = "System administrator";
};
nobody = {
uid = 65534;
shell = "${pkgs.shadow}/bin/nologin";
home = "/var/empty";
gid = 65534;
groups = [ "nobody" ];
description = "Unprivileged account (don't use!)";
};
} // lib.listToAttrs (
map
(
n: {
name = "nixbld${toString n}";
value = {
uid = 30000 + n;
gid = 30000;
groups = [ "nixbld" ];
description = "Nix build user ${toString n}";
};
}
)
(lib.lists.range 1 32)
);
groups = {
root.gid = 0;
nixbld.gid = 30000;
nobody.gid = 65534;
};
userToPasswd = (
k:
{ uid
, gid ? 65534
, home ? "/var/empty"
, description ? ""
, shell ? "/bin/false"
, groups ? [ ]
}: "${k}:x:${toString uid}:${toString gid}:${description}:${home}:${shell}"
);
passwdContents = (
lib.concatStringsSep "\n"
(lib.attrValues (lib.mapAttrs userToPasswd users))
);
userToShadow = k: { ... }: "${k}:!:1::::::";
shadowContents = (
lib.concatStringsSep "\n"
(lib.attrValues (lib.mapAttrs userToShadow users))
);
# Map groups to members
# {
# group = [ "user1" "user2" ];
# }
groupMemberMap = (
let
# Create a flat list of user/group mappings
mappings = (
builtins.foldl'
(
acc: user:
let
groups = users.${user}.groups or [ ];
in
acc ++ map
(group: {
inherit user group;
})
groups
)
[ ]
(lib.attrNames users)
);
in
(
builtins.foldl'
(
acc: v: acc // {
${v.group} = acc.${v.group} or [ ] ++ [ v.user ];
}
)
{ }
mappings)
);
groupToGroup = k: { gid }:
let
members = groupMemberMap.${k} or [ ];
in
"${k}:x:${toString gid}:${lib.concatStringsSep "," members}";
groupContents = (
lib.concatStringsSep "\n"
(lib.attrValues (lib.mapAttrs groupToGroup groups))
);
defaultNixConf = {
sandbox = "false";
build-users-group = "nixbld";
trusted-public-keys = [ "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=" ];
};
nixConfContents = (lib.concatStringsSep "\n" (lib.mapAttrsFlatten (n: v:
let
vStr = if builtins.isList v then lib.concatStringsSep " " v else v;
in
"${n} = ${vStr}") (defaultNixConf // nixConf))) + "\n";
baseSystem =
let
nixpkgs = pkgs.path;
channel = pkgs.runCommand "channel-nixos" { inherit bundleNixpkgs; } ''
mkdir $out
if [ "$bundleNixpkgs" ]; then
ln -s ${nixpkgs} $out/nixpkgs
echo "[]" > $out/manifest.nix
fi
'';
rootEnv = pkgs.buildPackages.buildEnv {
name = "root-profile-env";
paths = defaultPkgs;
};
manifest = pkgs.buildPackages.runCommand "manifest.nix" { } ''
cat > $out <<EOF
[
${lib.concatStringsSep "\n" (builtins.map (drv: let
outputs = drv.outputsToInstall or [ "out" ];
in ''
{
${lib.concatStringsSep "\n" (builtins.map (output: ''
${output} = { outPath = "${lib.getOutput output drv}"; };
'') outputs)}
outputs = [ ${lib.concatStringsSep " " (builtins.map (x: "\"${x}\"") outputs)} ];
name = "${drv.name}";
outPath = "${drv}";
system = "${drv.system}";
type = "derivation";
meta = { };
}
'') defaultPkgs)}
]
EOF
'';
profile = pkgs.buildPackages.runCommand "user-environment" { } ''
mkdir $out
cp -a ${rootEnv}/* $out/
ln -s ${manifest} $out/manifest.nix
'';
flake-registry-path = if (flake-registry == null) then
null
else if (builtins.readFileType (toString flake-registry)) == "directory" then
"${flake-registry}/flake-registry.json"
else
flake-registry;
in
pkgs.runCommand "base-system"
{
inherit passwdContents groupContents shadowContents nixConfContents;
passAsFile = [
"passwdContents"
"groupContents"
"shadowContents"
"nixConfContents"
];
allowSubstitutes = false;
preferLocalBuild = true;
} (''
env
set -x
mkdir -p $out/etc
mkdir -p $out/etc/ssl/certs
ln -s /nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt $out/etc/ssl/certs
cat $passwdContentsPath > $out/etc/passwd
echo "" >> $out/etc/passwd
cat $groupContentsPath > $out/etc/group
echo "" >> $out/etc/group
cat $shadowContentsPath > $out/etc/shadow
echo "" >> $out/etc/shadow
mkdir -p $out/usr
ln -s /nix/var/nix/profiles/share $out/usr/
mkdir -p $out/nix/var/nix/gcroots
mkdir $out/tmp
mkdir -p $out/var/tmp
mkdir -p $out/etc/nix
cat $nixConfContentsPath > $out/etc/nix/nix.conf
mkdir -p $out/root
mkdir -p $out/nix/var/nix/profiles/per-user/root
ln -s ${profile} $out/nix/var/nix/profiles/default-1-link
ln -s $out/nix/var/nix/profiles/default-1-link $out/nix/var/nix/profiles/default
ln -s /nix/var/nix/profiles/default $out/root/.nix-profile
ln -s ${channel} $out/nix/var/nix/profiles/per-user/root/channels-1-link
ln -s $out/nix/var/nix/profiles/per-user/root/channels-1-link $out/nix/var/nix/profiles/per-user/root/channels
mkdir -p $out/root/.nix-defexpr
ln -s $out/nix/var/nix/profiles/per-user/root/channels $out/root/.nix-defexpr/channels
echo "${channelURL} ${channelName}" > $out/root/.nix-channels
mkdir -p $out/bin $out/usr/bin
ln -s ${pkgs.coreutils}/bin/env $out/usr/bin/env
ln -s ${pkgs.bashInteractive}/bin/bash $out/bin/sh
'' + (lib.optionalString (flake-registry-path != null) ''
nixCacheDir="/root/.cache/nix"
mkdir -p $out$nixCacheDir
globalFlakeRegistryPath="$nixCacheDir/flake-registry.json"
ln -s ${flake-registry-path} $out$globalFlakeRegistryPath
mkdir -p $out/nix/var/nix/gcroots/auto
rootName=$(${pkgs.nix}/bin/nix --extra-experimental-features nix-command hash file --type sha1 --base32 <(echo -n $globalFlakeRegistryPath))
ln -s $globalFlakeRegistryPath $out/nix/var/nix/gcroots/auto/$rootName
''));
in
pkgs.dockerTools.buildLayeredImageWithNixDb {
inherit name tag maxLayers;
contents = [ baseSystem ];
extraCommands = ''
rm -rf nix-support
ln -s /nix/var/nix/profiles nix/var/nix/gcroots/profiles
'';
fakeRootCommands = ''
chmod 1777 tmp
chmod 1777 var/tmp
'';
config = {
Cmd = [ "/root/.nix-profile/bin/bash" ];
Env = [
"USER=root"
"PATH=${lib.concatStringsSep ":" [
"/root/.nix-profile/bin"
"/nix/var/nix/profiles/default/bin"
"/nix/var/nix/profiles/default/sbin"
]}"
"MANPATH=${lib.concatStringsSep ":" [
"/root/.nix-profile/share/man"
"/nix/var/nix/profiles/default/share/man"
]}"
"SSL_CERT_FILE=/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt"
"GIT_SSL_CAINFO=/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt"
"NIX_SSL_CERT_FILE=/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt"
"NIX_PATH=/nix/var/nix/profiles/per-user/root/channels:/root/.nix-defexpr/channels"
];
};
}