examples: add deploy-krops.sh

examples/README.md

@@ -20,6 +20,10 @@ By default, [`configuration.nix`](configuration.nix) enables `bitcoind` and `cli
 - [`./deploy-qemu-vm.sh`](deploy-qemu-vm.sh) creates a QEMU VM.\
   Requires: [Nix](https://nixos.org/nix/)
 
+- [`./deploy-krops.sh`](deploy-krops.sh) creates a QEMU VM and deploys a
+  nix-bitcoin configuration to it using [krops](https://github.com/krebs/krops).\
+  Requires: [Nix](https://nixos.org/nix/)
+
 - [`./deploy-container-minimal.sh`](deploy-container-minimal.sh) creates a
   container defined by [minimal-configuration.nix](minimal-configuration.nix) that
   doesn't use the [secure-node.nix](../modules/presets/secure-node.nix) preset.

examples/deploy-krops.sh

@@ -0,0 +1,122 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# This script demonstrates how to setup a nix-bitcoin node with krops.
+# The node is deployed to a minimal NixOS QEMU VM.
+# Running this script leaves no traces on your host system.
+
+# This demo is a template for your own experiments.
+# Run with option `--interactive` or `-i` to start a shell for interacting with
+# the node.
+
+# MAKE SURE TO REPLACE the SSH identity file if you use this script for
+# anything serious.
+
+if [[ ! -v IN_NIX_SHELL ]]; then
+    echo "Running script in nix shell env..."
+    cd "${BASH_SOURCE[0]%/*}"
+    exec nix-shell --run "./${BASH_SOURCE[0]##*/} $*"
+fi
+
+source qemu-vm/run-vm.sh
+
+echo "Building the target VM"
+# Build the initial VM to which the nix-bitcoin node is deployed via krops
+nix-build --out-link $tmpDir/vm - <<'EOF'
+(import <nixpkgs/nixos> {
+  configuration = { lib, ... }: {
+    imports = [ <qemu-vm/vm-config.nix>  ];
+    services.openssh.enable = true;
+
+    # Silence the following warning that appears when deploying via krops:
+    # warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
+    nix.nixPath = lib.mkForce [];
+  };
+}).vm
+EOF
+
+vmNumCPUs=4
+vmMemoryMiB=2048
+sshPort=60734
+# Start the VM in the background
+runVM $tmpDir/vm $vmNumCPUs $vmMemoryMiB $sshPort
+
+# Build the krops deploy script
+export sshPort
+nix-build --out-link $tmpDir/krops-deploy - <<'EOF'
+let
+  krops = (import <nix-bitcoin> {}).krops;
+
+  extraSources = {
+    # Skip uploading nixpkgs to the target node.
+    # This works because /nix/store is shared with the target VM.
+    nixpkgs.symlink = toString <nixpkgs>;
+
+    nixos-config.file = toString <krops-vm-configuration.nix>;
+
+    qemu-vm.file = toString <qemu-vm>;
+  };
+in
+krops.pkgs.krops.writeCommand "krops-deploy" {
+  source = import <krops/sources.nix> { inherit extraSources krops; };
+  force = true;
+  target = {
+    user = "root";
+    host = "127.0.0.1";
+    port = builtins.getEnv "sshPort";
+    extraOptions = [
+      "-i" (toString <qemu-vm/id-vm>) "-oConnectTimeout=1"
+      "-oStrictHostKeyChecking=no" "-oUserKnownHostsFile=/dev/null" "-oLogLevel=ERROR"
+      "-oControlMaster=auto" "-oControlPath=${builtins.getEnv "tmpDir"}/ssh-connection" "-oControlPersist=60"
+    ];
+  };
+
+  # "test" instead of "switch" to avoid installing a bootloader which
+  # is not possible in this VM
+  command = targetPath: ''
+    nixos-rebuild test -I /var/src
+  '';
+}
+EOF
+
+echo "Building the nix-bitcoin node"
+# Pre-build the nix-bitcoin node outside of the VM to save some time
+nix-build --out-link $tmpDir/store-paths -E '
+let
+  system = (import <nixpkgs/nixos> { configuration = <krops-vm-configuration.nix>; }).system;
+  pkgsUnstable = (import <nix-bitcoin/pkgs/nixpkgs-pinned.nix>).nixpkgs-unstable;
+  pkgs = import <nixpkgs> {};
+in
+  pkgs.closureInfo { rootPaths = [ system pkgsUnstable ]; }
+' > /dev/null
+
+vmWaitForSSH
+
+# Add the store paths that include the nix-bitcoin node
+# to the nix store db in the VM
+c "nix-store --load-db < $(realpath $tmpDir/store-paths)/registration"
+
+echo
+echo "Deploy with krops"
+$tmpDir/krops-deploy
+
+echo
+echo "Bitcoind service:"
+c systemctl status bitcoind
+echo
+echo "Bitcoind network:"
+c bitcoin-cli getnetworkinfo
+echo
+echo "lightning-cli state:"
+c lightning-cli getinfo
+echo
+echo "Node info:"
+c nodeinfo
+
+case ${1:-} in
+    -i|--interactive)
+        . start-bash-session.sh
+        ;;
+esac
+
+# Cleanup happens at exit (defined in qemu-vm/run-vm.sh)

examples/krops-vm-configuration.nix

@@ -0,0 +1,8 @@
+{ lib, ... }: {
+  imports = [
+    ./configuration.nix
+    <nix-bitcoin/modules/deployment/krops.nix>
+    <qemu-vm/vm-config.nix>
+    <nixpkgs/nixos/modules/virtualisation/qemu-vm.nix>
+  ];
+}

test/run-tests.sh

@@ -249,6 +249,7 @@ examples() {
       set -e
       ./deploy-container.sh
       ./deploy-qemu-vm.sh
+      ./deploy-krops.sh
     "
     (cd $scriptDir/../examples && nix-shell --run "$script")
 }