Deployment Keys Basics

Deploy some basic secrets with wire tool.

Creating a secrets.nix

Lets create a NixOS module that will contain our secret keys, and import it:

hive.nix

let
  sources = import ./npins;
  wire = import sources.wire;
in
wire.makeHive {
  meta.nixpkgs = import sources.nixpkgs { };

  virtual-machine = {
    deployment.target = {
        port = 2222;
        hosts = [ "localhost" ];
    };

    imports = [
        ./vm.nix
        ./secrets.nix
    ];

    environment.systemPackages = [ pkgs.vim ];

    nixpkgs.hostPlatform = "x86_64-linux";
  };
}

secrets.nix

{
  deployment.keys = {
    # the key's unique name is `"basic.txt"`.
    "basic.txt" = {
      # In this key's case, the source is a literal string:
      source = ''
        Hello World
      '';
    };
  };
}

Details

Further details on the deployment.keys options can be found in the reference

Once we deploy this new configuration to the virtul machine, /run/keys/basic.txt will be created with the contents of the key.

[nix-shell]$ wire apply keys
 WARN lib::nix_log: Store URL: ssh://root@localhost
(root@localhost) Password:

Virtual Machine

[root@wire-tutorial:~]# cat /run/keys/basic.txt
Hello World

You successfully deployed your first, albeit not-so-secret, secret key! Let's move on from literal-text keys and use something a bit more powerful.

File-sourced keys Optional

This section is optional to try, but you can also pass deployment.keys.<name>.source a file path. It's contents is read and treated as literal text.

$ echo hello world > very-important-secret.txt

secrets.nix

{
  deployment.keys = {
    # ...

    "very-important-secret.txt" = { 
      source = ./very-important-secret.txt; 
    }; 
  };
}

Virtual Machine

[root@wire-tutorial:~]# cat /run/keys/very-important-secret.txt
hello world

Command-sourced keys

Command-sourced keys are where the real power of wire keys lie. By passing a list of strings, wire will execute them as a command and create a key out of it's stdout.

Because the command's output is never written to the nix store, these can be considered real secrets.

To create a basic example, update your secrets.nix to include a secret that echos "hello world":

secrets.nix

{
  deployment.keys = {
    # ...

    "command.txt" = { 
      source = [ 
        "echo"
        "hello world"
      ]; 
    }; 
  };
}

After a quick wire deploy secrets, the /run/keys/command.txt file is created:

Virtual Machine

[root@wire-tutorial:~]# cat /run/keys/command.txt
hello world

Hopefully you can see the potential of command-sourced keys, as these are the basic building block of how we achieve encrypted secrets with wire.