run services in docker in nixos in wsl(2)

readme.md

Set up (pointers here) nixos first.

running the container like this docker run --name redis -dit -p 0.0.0.0:6379:6379 imagename (microsoft/WSL#5618 (comment)) let's you from the host windows do either:

Create [#file-redis-small.nix] like this (mod of https://yann.hodique.info/blog/using-nix-to-build-docker-images/, source: https://gist.github.com/sigma/9887c299da60955734f0fff6e2faeee0, this again modding http://lethalman.blogspot.com/2016/04/cheap-docker-images-with-nix_15.html, latter via https://nixos.wiki/wiki/Docker)

curl localhost:6379

or

NIX_PATH=nixpkgs=http://nixos.org/channels/nixpkgs-unstable/nixexprs.tar.xz nix-shell -p redis redis-cli -c

Works even with VPN active once the docker container is started at least.

redis-small.nix

{ pkgs ? import <nixpkgs> {} }:

with pkgs;
let
su_exec = stdenv.mkDerivation {
    name = "su-exec-0.2";
    src = fetchurl {
      url = https://github.com/ncopa/su-exec/archive/v0.2.tar.gz;
      sha256 = "09ayhm4w7ahvwk6wpjimvgv8lx89qx31znkywqmypkp6rpccnjpc";
    };
    preBuild = ''
      makeFlagsArray=(CC="${musl.dev}/bin/musl-gcc -static"
                      CFLAGS="-I${musl.dev}/include"
                      LDFLAGS="-L${musl.dev}/lib")
    '';
    buildFlags = "su-exec-static";
    installPhase = ''mkdir -p $out/bin && cp su-exec-static $out/bin/su-exec'';
  };
in
dockerTools.buildImage {
  name = "redis";
  runAsRoot = ''
   #!${stdenv.shell}
      export PATH=/bin:/usr/bin:/sbin:/usr/sbin:$PATH
      ${dockerTools.shadowSetup}
      groupadd -r redis
      useradd -r -g redis -d /data -M redis
      mkdir /data
      chown redis:redis /data
      ${gnused}/bin/sed -i 's:/nix/.*bash.*::' etc/passwd
      ${gnused}/bin/sed -i 's:/nix/.*bash.*::' etc/passwd-
  '';

  config = {
Cmd = [ "${su_exec}/bin/su-exec" "redis" "${redis}/bin/redis-server" ];
      ExposedPorts = {
        "6379/tcp" = {};
      };
      WorkingDir = "/data";
      Volumes = {
        "/data" = {};
      };
  };
}