Nix service thing for Docker

docker-services.nix

{ config, pkgs, ... }:

let dockerService = {
  name,
  vhosts ? [],
  public ? (if builtins.length vhosts > 0 then true else false),
  image,
  user ? "docker",
  cmd ? "",
  volumes ? [],
  ports ? [],
  environment ? []
}: {
  wantedBy = ["multi-user.target"];
  after = ["docker.service"];
  requires = ["docker.service"];

  serviceConfig = {
    User = user;
    ExecStartPre = ''
      -${pkgs.docker}/bin/docker rm -f ${name}
    '';
    ExecStart = ''
      ${pkgs.docker}/bin/docker run \
        ${builtins.concatStringsSep " " (map (p: "-p ${p}") ports)} \
        ${builtins.concatStringsSep " " (map (v: "-v ${v}") volumes)} \
        ${builtins.concatStringsSep " " (map (e: "-e ${e}") environment)} \
        ${if public then
           "-e VIRTUAL_HOST=${
              builtins.concatStringsSep ","
                (vhosts ++ (if public then ["~^${name}\\..*"] else []))}"
          else
           ""} \
        --name=${name} --user=${user} ${image} ${cmd}
    '';
    ExecStop = ''
      ${pkgs.docker}/bin/docker stop ${name} ; \
      ${pkgs.docker}/bin/docker rm -f ${name}
    '';
  };
};

in {

  # "example" = dockerService {
  #   name = "example";
  #   image = "node";
  #   public = true;
  #   ports = ["80"];
  #   vhosts = ["api.example.com"];
  #   cmd = "node /app/server.js";
  #   volumes = ["/src/example:/app:ro"];
  # };


  ## This image makes automatic reverse proxies based on the vhosts

  # proxy = dockerService {
  #   name = "proxy";
  #   image = "jwilder/nginx-proxy";
  #   ports = ["80:80"];
  #   volumes = ["/var/run/docker.sock:/tmp/docker.sock:ro"];
  # };

};