Building a nix derivation within a module - containers

Question

I created the following module services/invidious.nix
{ pkgs, stdenv, ... }:
stdenv.mkDerivation {
name = "invidious";
container = pkgs.dockerTools.buildLayeredImage {
name = "invidious";
contents = [ pkgs.busybox pkgs.bash pkgs.invidious ];
config = {
Cmd = [ "/bin/bash" ];
Env = [];
Volumes = {};
};
};
}
My eventual goal is to have several services in modules and use nix-build to build each of those services as containers, and write the resulting image names to a file:
let
config = import ./config.nix;
pkgs = config.pkgs;
invidious = import ./services/invidious.nix;
in rec {
serviceimages = pkgs.writeText "images.txt" ''
${invidious(pkgs)}
'';
}
and my config.nix just has the pkgs pinned version:
{
# nixos-22.05 / https://status.nixos.org/
pkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/d86a4619b7e80bddb6c01bc01a954f368c56d1df.tar.gz") {};
}
However, when I use nix-build, I get the following error:
nix-build services.nix -A serviceimages
these 2 derivations will be built:
/nix/store/dbl3bzc05pssq3q9g8wd2i92xpmwf5bb-invidious.drv
/nix/store/4x31hx9nxcbbksi2hsim08djrsj4h1zh-images.txt.drv
building '/nix/store/dbl3bzc05pssq3q9g8wd2i92xpmwf5bb-invidious.drv'...
unpacking sources
variable $src or $srcs should point to the source
error: builder for '/nix/store/dbl3bzc05pssq3q9g8wd2i92xpmwf5bb-invidious.drv' failed with exit code 1;
last 2 log lines:
> unpacking sources
> variable $src or $srcs should point to the source
For full logs, run 'nix log /nix/store/dbl3bzc05pssq3q9g8wd2i92xpmwf5bb-invidious.drv'.
If I try to pull the full logs using the command given, I get the following:
nix log /nix/store/dbl3bzc05pssq3q9g8wd2i92xpmwf5bb-invidious.drv
error: experimental Nix feature 'nix-command' is disabled; use '--extra-experimental-features nix-command' to override
...and if I enable the experimental feature, I see the following:
nix --extra-experimental-features nix-command log /nix/store/dbl3bzc05pssq3q9g8wd2i92xpmwf5bb-invidious.drv
#nix { "action": "setPhase", "phase": "unpackPhase" }
unpacking sources
variable $src or $srcs should point to the source
If I just try to build the same service in a single file, it successfully builds the image:
let
# nixos-22.05 / https://status.nixos.org/
pkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/d86a4619b7e80bddb6c01bc01a954f368c56d1df.tar.gz") {};
in rec {
docker = pkgs.dockerTools.buildLayeredImage {
name = "invidious";
contents = [ pkgs.busybox pkgs.bash pkgs.invidious ];
config = {
Cmd = [ "/bin/sh" ];
Env = [];
Volumes = {};
};
};
results = pkgs.writeText "images.txt" ''
${docker}
'';
}
What am I doing wrong with my attempt to use modules?

Answer 1

I figured it out. I didn't need the mkDerivation. I just need the buildLayeredImage
{ pkgs, ... }:
pkgs.dockerTools.buildLayeredImage {
name = "invidious";
contents = [ pkgs.busybox pkgs.bash pkgs.invidious ];
config = {
Cmd = [ "/bin/bash" ];
Env = [];
Volumes = {};
};
}
The service.nix and config.nix stay the same:
let
config = import ./config.nix;
pkgs = config.pkgs;
invidious = import ./services/invidious.nix;
in rec {
serviceimages = pkgs.writeText "images.txt" ''
${invidious(pkgs)}
'';
}
{
# nixos-22.05 / https://status.nixos.org/
pkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/d86a4619b7e80bddb6c01bc01a954f368c56d1df.tar.gz") {};
}