Change the nix-bitcoin deployment from forking this repo to importing the module

Instead of forking this repo, it is now recommended that users simply import the
nix-bitcoin module. This commit adds an example directory that contains the
network/ examples and a shell.nix for deployment with nixops.

examples/configuration.nix

@@ -0,0 +1,144 @@
+# Edit this configuration file to define what should be installed on
+# your system.  Help is available in the configuration.nix(5) man page
+# and in the NixOS manual (accessible by running ‘nixos-help’).
+
+{ config, pkgs, lib, ... }: {
+  imports = [
+    # Use hardened kernel profile. See
+    # https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/profiles/hardened.nix
+    # for the enabled options.
+     <nixpkgs/nixos/modules/profiles/hardened.nix>
+
+    # FIXME: Uncomment next line to import your hardware configuration. If so,
+    # add the hardware configuration file to the same directory as this file.
+    # This is not needed when deploying to a virtual box.
+    #./hardware-configuration.nix
+  ];
+  # FIXME: Enable modules by uncommenting their respective line. Disable
+  # modules by commenting out their respective line.  Enable this module to
+  # use the nix-bitcoin node configuration. Only disable this if you know what
+  # you are doing.
+  services.nix-bitcoin.enable = true;
+
+  ### BITCOIND
+  # Bitcoind is enabled by default if nix-bitcoin is enabled
+  #
+  # You can override default settings from nix-bitcoin.nix as follows
+  # services.bitcoind.prune = lib.mkForce 100000;
+  #
+  # You can add options that are not defined in modules/bitcoind.nix as follows
+  # services.bitcoind.extraConfig = ''
+  #   maxorphantx=110
+  # '';
+
+  ### CLIGHTNING
+  # Enable this module to use clightning, a Lightning Network implementation
+  # in C.
+  services.clightning.enable = true;
+  # Enable this option to listen for incoming lightning connections. By
+  # default nix-bitcoin nodes offer outgoing connectivity.
+  # services.clightning.autolisten = true;
+
+  ### LND
+  # Disable clightning and uncomment the following line in order to enable lnd,
+  # a lightning implementation written in Go.
+  # services.lnd.enable = assert (!config.services.clightning.enable); true;
+  ## WARNING
+  # If you use lnd, you should manually backup your wallet mnemonic
+  # seed. This will allow you to recover on-chain funds. You can run the
+  # following command after the lnd service starts:
+  # nixops scp --from bitcoin-node /secrets/lnd-seed-mnemonic ./secrets/lnd-seed-mnemonic
+  # You should also backup your channel state after opening new channels.
+  # This will allow you to recover off-chain funds, by force-closing channels.
+  # nixops scp --from bitcoin-node /var/lib/lnd/chain/bitcoin/mainnet/channel.backup /my-backup-path/channel.backup
+
+  ### SPARK WALLET
+  # Enable this module to use spark-wallet, a minimalistic wallet GUI for
+  # c-lightning, accessible over the web or through mobile and desktop apps.
+  # Only enable this if clightning is enabled.
+  # services.spark-wallet.enable = true;
+
+  ### ELECTRS
+  # Enable this module to use electrs, an efficient re-implementation of
+  # Electrum Server in Rust. Only enable this if hardware wallets are
+  # disabled.
+  # services.electrs.enable = true;
+  # If you have ≥8GB memory, enable this option so electrs will sync faster.
+  # services.electrs.high-memory = true;
+
+  ### LIQUIDD
+  # Enable this module to use Liquid, a sidechain for an inter-exchange
+  # settlement network linking together cryptocurrency exchanges and
+  # institutions around the world. Liquid is accessed with the elements-cli
+  # tool run as user operator.
+  # services.liquidd.enable = true;
+
+  ### LIGHTNING CHARGE
+  # Enable this module to use lightning-charge, a simple drop-in solution for
+  # accepting lightning payments. Only enable this if clightning is enabled.
+  # services.lightning-charge.enable = true;
+
+  ### NANOPOS
+  # Enable this module to use nanopos, a simple Lightning point-of-sale
+  # system, powered by Lightning Charge. Only enable this if clightning and
+  # lightning-charge are enabled.
+  # services.nanopos.enable = true;
+
+  ### WEBINDEX
+  # Enable this module to use the nix-bitcoin-webindex, a simple website
+  # displaying your node information and link to nanopos store. Only enable
+  # this if clightning, lightning-charge, and nanopos are enabled.
+  # services.nix-bitcoin-webindex.enable = true;
+
+  ### RECURRING-DONATIONS
+  # Enable this module to send recurring donations. This is EXPERIMENTAL; it's
+  # not guaranteed that payments are succeeding or that you will notice payment
+  # failure. Only enable this if clightning is enabled.
+  # services.recurring-donations.enable = true;
+  # Specify the receivers of the donations. By default donations are every
+  # Monday at a randomized time. Check `journalctl -eu recurring-donations` or
+  # `lightning-cli listpayments` for successful lightning donations.
+  # services.recurring-donations.tallycoin = {
+  #   "<receiver name>" = <amount you wish to donate in sat>"
+  #   "<additional receiver name>" = <amount you wish to donate in sat>;
+  #   "djbooth007" = 1000;
+  # };
+
+  ### Hardware wallets
+  # Enable this module to allow using hardware wallets. See https://github.com/bitcoin-core/HWI
+  # for more information. Only enable this if electrs is disabled.
+  # Ledger must be initialized through the official ledger live app and the Bitcoin app must
+  # be installed and running on the device.
+  # services.hardware-wallets.ledger = true;
+  # Trezor can be initialized with the trezorctl command in nix-bitcoin. More information in
+  # `docs/usage.md`.
+  # services.hardware-wallets.trezor = true;
+
+  # FIXME: Define your hostname.
+  networking.hostName = "nix-bitcoin";
+  time.timeZone = "UTC";
+
+  # FIXME: Add your SSH pubkey
+  services.openssh.enable = true;
+  users.users.root = {
+    openssh.authorizedKeys.keys = [ "" ];
+  };
+
+  # FIXME: add packages you need in your system
+  environment.systemPackages = with pkgs; [
+    vim
+  ];
+
+  # FIXME: Add custom options (like boot options, output of
+  # nixos-generate-config, etc.):
+
+  # If the hardened profile is imported above, we need to explicitly allow
+  # user namespaces to enable sanboxed builds and services.
+  security.allowUserNamespaces = true;
+
+  # This value determines the NixOS release with which your system is to be
+  # compatible, in order to avoid breaking some software such as database
+  # servers. You should change this only after NixOS release notes say you
+  # should.
+  system.stateVersion = "18.09"; # Did you read the comment?
+}

examples/nixops/node-libvirtd.nix

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+{
+  bitcoin-node =
+    { config, pkgs, ... }:
+    {
+      deployment.targetEnv = "libvirtd";
+      deployment.libvirtd.memorySize = 8192; # megabytes
+      deployment.libvirtd.vcpu = 4; # number of cpus
+      deployment.libvirtd.headless = true;
+      deployment.libvirtd.baseImageSize = 400;
+      boot.kernelParams = [ "console=ttyS0,115200" ];
+      deployment.libvirtd.extraDevicesXML = ''
+        <serial type='pty'>
+          <target port='0'/>
+       </serial>
+        <console type='pty'>
+          <target type='serial' port='0'/>
+       </console>
+      '';
+      # Remove when fixed: https://github.com/NixOS/nixops/issues/931
+      system.activationScripts.nixops-vm-fix-931 = {
+        text = ''
+          if ls -l /nix/store | grep sudo | grep -q nogroup; then
+            mount -o remount,rw  /nix/store
+            chown -R root:nixbld /nix/store
+          fi
+        '';
+        deps = [];
+      };
+    };
+}

examples/nixops/node-vbox.nix

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+{
+  bitcoin-node =
+    { config, pkgs, ... }:
+    {
+      deployment.targetEnv = "virtualbox";
+      deployment.virtualbox = {
+        memorySize = 4096; # megabytes
+        vcpu = 4; # number of cpus
+        disks.disk1.size = 358400; # 350 GiB
+        headless = true;
+      };
+    };
+}

examples/nixops/node.nix

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+{
+  network.description = "Bitcoin Core node";
+
+  bitcoin-node =
+    { config, pkgs, lib, ... }: {
+      imports = [ ../configuration.nix <nix-bitcoin/modules/nix-bitcoin.nix> ];
+
+      deployment.keys = builtins.mapAttrs (n: v: {
+        keyFile = "${toString ../secrets}/${n}";
+        destDir = config.nix-bitcoin.secretsDir;
+        inherit (v) user group permissions;
+      }) config.nix-bitcoin.secrets;
+
+      # nixops makes the secrets directory accessible only for users with group 'key'.
+      # For compatibility with other deployment methods besides nixops, we forego the
+      # use of the 'key' group and make the secrets dir world-readable instead.
+      # This is safe because all containing files have their specific private
+      # permissions set.
+      systemd.services.allowSecretsDirAccess = {
+        requires = [ "keys.target" ];
+        after = [ "keys.target" ];
+        script = "chmod o+x ${config.nix-bitcoin.secretsDir}";
+        serviceConfig.Type = "oneshot";
+      };
+
+      systemd.targets.nix-bitcoin-secrets = {
+        requires = [ "allowSecretsDirAccess.service" ];
+        after = [ "allowSecretsDirAccess.service" ];
+      };
+    };
+}

examples/shell.nix

@@ -0,0 +1,29 @@
+let
+  # TODO:
+  # nix-bitcoin-path = builtins.fetchTarball {
+  #   url = "https://github.com/fort-nix/nix-bitcoin/archive/master.tar.gz";
+  #   sha256 = "1mlvfakjgbl67k4k9mgafp5gvi2gb2p57xwxwffqr4chx8g848n7";
+  # };
+  nix-bitcoin-path = ../.;
+  nixpkgs-path = (import "${toString nix-bitcoin-path}/pkgs/nixpkgs-pinned.nix").nixpkgs;
+  nixpkgs = import nixpkgs-path {};
+  nix-bitcoin = nixpkgs.callPackage nix-bitcoin-path {};
+in
+with nixpkgs;
+
+stdenv.mkDerivation rec {
+  name = "nix-bitcoin-environment";
+
+  buildInputs = [ nix-bitcoin.nixops19_09 figlet ];
+
+  shellHook = ''
+    export NIX_PATH="nixpkgs=${nixpkgs-path}:nix-bitcoin=${toString nix-bitcoin-path}:."
+    # ssh-agent and nixops don't play well together (see
+    # https://github.com/NixOS/nixops/issues/256). I'm getting `Received disconnect
+    # from 10.1.1.200 port 22:2: Too many authentication failures` if I have a few
+    # keys already added to my ssh-agent.
+    export SSH_AUTH_SOCK=""
+    figlet "nix-bitcoin"
+    (mkdir -p secrets; cd secrets; ${nix-bitcoin.generate-secrets})
+  '';
+}