lix/docker.nix
jade 9aeb314e6a releng: support multiarch docker images
If we don't want to have separate registry tags by architecture (EWWWW),
we need to be able to build multiarch docker images. This is pretty
simple, and just requires making a manifest pointing to each of the
component images.

I was *going* to just do this API prodding with manifest-tool, but it
doesn't support putting metadata on the outer manifest, which is
actually kind of a problem because it then doesn't render the metadata
on github. So I guess we get a simple little containers API
implementation that is 90% auth code.

Change-Id: I8bdd118d4cbc13b23224f2fb174b232432686bea
2024-06-09 20:33:24 -07:00

402 lines
11 KiB
Nix

{
pkgs ? import <nixpkgs> { },
# Git commit ID, if available
lixRevision ? null,
nix2container,
lib ? pkgs.lib,
name ? "lix",
tag ? "latest",
bundleNixpkgs ? true,
channelName ? "nixpkgs",
channelURL ? "https://nixos.org/channels/nixpkgs-unstable",
extraPkgs ? [ ],
maxLayers ? 100,
nixConf ? { },
flake-registry ? null,
}:
let
layerContents = with pkgs; [
# pulls in glibc and openssl, about 60MB
{ contents = [ coreutils-full ]; }
# some stuff that is low in the closure graph and small ish, mostly to make
# incremental lix updates cheaper
{
contents = [
curl
libxml2
sqlite
];
}
# 50MB of git
{ contents = [ gitMinimal ]; }
# 144MB of nixpkgs
{
contents = [ channel ];
inProfile = false;
}
];
# These packages are left to be auto layered by nix2container, since it is
# less critical that they get layered sensibly and they tend to not be deps
# of anything in particular
autoLayered = with pkgs; [
bashInteractive
gnutar
gzip
gnugrep
which
less
wget
man
cacert.out
findutils
iana-etc
openssh
nix
];
defaultPkgs =
lib.lists.flatten (
map (x: if !(x ? inProfile) || x.inProfile then x.contents else [ ]) layerContents
)
++ autoLayered
++ 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";
nixpkgs = pkgs.path;
channel = pkgs.runCommand "channel-nixpkgs" { } ''
mkdir $out
${lib.optionalString bundleNixpkgs ''
ln -s ${nixpkgs} $out/nixpkgs
echo "[]" > $out/manifest.nix
''}
'';
baseSystem =
let
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 -sf ${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
ln -s /nix/var/nix/profiles $out/nix/var/nix/gcroots/profiles
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 /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 /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 /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
'')
);
layers = builtins.foldl' (
layersList: el:
let
layer = nix2container.buildLayer {
deps = el.contents;
layers = layersList;
};
in
layersList ++ [ layer ]
) [ ] layerContents;
image = nix2container.buildImage {
inherit name tag maxLayers;
inherit layers;
copyToRoot = [ baseSystem ];
initializeNixDatabase = true;
perms = [
{
path = baseSystem;
regex = "(/var)?/tmp";
mode = "1777";
}
];
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"
];
Labels = {
"org.opencontainers.image.title" = "Lix";
"org.opencontainers.image.source" = "https://git.lix.systems/lix-project/lix";
"org.opencontainers.image.vendor" = "Lix project";
"org.opencontainers.image.version" = pkgs.nix.version;
"org.opencontainers.image.description" = "Minimal Lix container image, with some batteries included.";
} // lib.optionalAttrs (lixRevision != null) { "org.opencontainers.image.revision" = lixRevision; };
};
meta = {
description = "Docker image for Lix. This is built with nix2container; see that project's README for details";
longDescription = ''
Docker image for Lix, built with nix2container.
To copy it to your docker daemon, nix run .#dockerImage.copyToDockerDaemon
To copy it to podman, nix run .#dockerImage.copyTo containers-storage:lix
'';
};
};
in
image
// {
# We don't ship the tarball as the default output because it is a strange thing to want imo
tarball =
pkgs.buildPackages.runCommand "docker-image-tarball-${pkgs.nix.version}"
{
nativeBuildInputs = [ pkgs.buildPackages.bubblewrap ];
meta.description = "Docker image tarball with Lix for ${pkgs.system}";
}
''
mkdir -p $out/nix-support
image=$out/image.tar
# bwrap for foolish temp dir selection code that forces /var/tmp:
# https://github.com/containers/skopeo.git/blob/60ee543f7f7c242f46cc3a7541d9ac8ab1c89168/vendor/github.com/containers/image/v5/internal/tmpdir/tmpdir.go#L15-L18
mkdir -p $TMPDIR/fake-var/tmp
args=(--unshare-user --bind "$TMPDIR/fake-var" /var)
for dir in /*; do
args+=(--dev-bind "/$dir" "/$dir")
done
bwrap ''${args[@]} -- ${lib.getExe image.copyTo} docker-archive:$image
gzip $image
echo "file binary-dist $image" >> $out/nix-support/hydra-build-products
'';
}