devenv.nix Options Reference: Complete Configuration API

packages = [ pkgs.git pkgs.ripgrep pkgs.curl ];

env = {
  GREET = "hello";
  DATABASE_URL = "postgres://localhost:5432/mydb";
  DEBUG = "true";
};

enterShell = ''
  echo "Welcome to the dev environment!"
  git --version
  hello  # run a script
'';

enterTest = ''
  echo "Running tests"
  git --version | grep "${pkgs.git.version}"
  wait_for_port 5432  # wait for postgres
  pytest tests/
'';

overlays = [
  (final: prev: {
    hello = prev.hello.overrideAttrs (old: {
      patches = (old.patches or []) ++ [ ./hello-fix.patch ];
    });
  })
];

scripts = {
  hello.exec = ''echo "Hello from $GREET"'';
  hello.description = "Print a greeting";

  db-reset = {
    exec = ''
      psql "$DATABASE_URL" -c "DROP SCHEMA public CASCADE; CREATE SCHEMA public;"
    '';
    description = "Reset the database schema";
    packages = [ pkgs.postgresql ];
  };
};

tasks = {
  "myapp:setup".exec = "mytool build";
  "myapp:db-migrate" = {
    exec = "alembic upgrade head";
    after = [ "devenv:enterShell" ];
    execIfModified = [ "migrations/" ];
  };
  "devenv:enterShell".after = [ "myapp:setup" ];
};

processes = {
  server = {
    exec = "uvicorn myapp:app --reload --port 8000";
    ready.http.get = {
      host = "localhost";
      path = "/health";
      port = 8000;
      scheme = "http";
    };
  };
  worker = {
    exec = "celery -A myapp worker";
    after = [ "devenv:processes:postgres@ready" ];
    restart.on = "on_failure";
    restart.max = 5;
  };
};

containers.app = {
  name = "myapp";
  version = "1.0.0";
  startupCommand = config.processes.server.exec;
  registry = "ghcr.io/myorg/";
};

outputs = {
  git = pkgs.git;
  # Language-specific app packaging:
  rust-app = config.languages.rust.import ./rust-app {};
  python-app = config.languages.python.import ./python-app {};
};

profiles = {
  base.module = {
    languages.nix.enable = true;
    packages = [ pkgs.git ];
  };
  backend = {
    extends = [ "base" ];
    module = {
      services.postgres.enable = true;
      services.redis.enable = true;
    };
  };
  hostname."work-laptop" = {
    extends = [ "backend" ];
    module.env.WORK = "true";
  };
};

files = {
  ".editorconfig".text = ''
    root = true
    [*]
    indent_style = space
    indent_size = 2
  '';
  "config/settings.json".json = {
    debug = false;
    logLevel = "info";
  };
};

git-hooks.hooks = {
  shellcheck.enable = true;
  nixfmt-rfc-style.enable = true;
  clippy.enable = true;
  # Custom hook:
  my-linter = {
    enable = true;
    entry = "${pkgs.my-linter}/bin/lint";
    files = "\\.py$";
    types = [ "python" ];
  };
};