add deploy-qemu-vm.sh example

README.md

@@ -24,8 +24,7 @@ It should be a reproducible and extensible platform for applications building on
 
 Example
 ---
-The easiest way is to try out nix-bitcoin is to use one of the provided examples.
-This requires that you either have NixOS installed or another Linux distribution with [Nix](https://nixos.org/nix/) and [VirtualBox](https://www.virtualbox.org).
+The easiest way to try out nix-bitcoin is to use one of the provided examples.
 
 ```
 git clone https://github.com/fort-nix/nix-bitcoin
@@ -33,8 +32,19 @@ cd examples/
 nix-shell
 ```
 
-Now you can run `./deploy-nixops.sh` to install nix-bitcoin in a VirtualBox or `./deploy-container.sh` to install in a [NixOS container](https://github.com/erikarvstedt/extra-container).
-This will set up a nix-bitcoin according to `examples/configuration.nix` and then shut down immediately.
+The following example scripts set up a nix-bitcoin node according to `examples/configuration.nix` and then
+shut down immediately. They leave no traces (outside of `/nix/store`) on the host system.
+
+- `./deploy-container.sh` creates a [NixOS container](https://github.com/erikarvstedt/extra-container).\
+  This is the fastest way to set up a node.\
+  Requires: [NixOS](https://nixos.org/)
+
+- `./deploy-qemu-vm.sh` creates a QEMU VM.\
+  Requires: [Nix](https://nixos.org/nix/)
+
+- `./deploy-nixops.sh` creates a VirtualBox VM via [NixOps](https://github.com/NixOS/nixops).\
+  NixOps can be used to deploy to various other backends like cloud providers.\
+  Requires: [Nix](https://nixos.org/nix/), [VirtualBox](https://www.virtualbox.org)
 
 Available modules
 ---

examples/deploy-qemu-vm.sh

@@ -0,0 +1,93 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# This script demonstrates how to run a nix-bitcoin node in QEMU.
+# Running this script leaves no traces on your host system.
+
+# This demo is a template for your own experiments.
+# Feel free to modify or to run nix-shell and execute individual statements of this
+# script in the interactive shell.
+
+# 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..."
+    exec nix-shell --run "${BASH_SOURCE[0]}"
+fi
+
+tmpDir=/tmp/nix-bitcoin-qemu-vm
+mkdir -p $tmpDir
+
+# Cleanup on exit
+cleanup() {
+    set +eu
+    kill -9 $qemuPID
+    rm -rf $tmpDir
+}
+trap "cleanup" EXIT
+
+identityFile=qemu-vm/id-vm
+chmod 0600 $identityFile
+
+echo "Building VM"
+nix-build --out-link $tmpDir/vm - <<EOF
+(import <nixpkgs/nixos> {
+  configuration = {
+    imports = [
+      <nix-bitcoin/examples/configuration.nix>
+      <nix-bitcoin/modules/secrets/generate-secrets.nix>
+    ];
+    virtualisation.graphics = false;
+    services.mingetty.autologinUser = "root";
+    users.users.root = {
+      openssh.authorizedKeys.keys = [ "$(cat $identityFile.pub)" ];
+    };
+  };
+}).vm
+EOF
+
+vmMemoryMiB=2048
+vmNumCPUs=4
+sshPort=60734
+
+export NIX_DISK_IMAGE=$tmpDir/img
+export QEMU_NET_OPTS=hostfwd=tcp::$sshPort-:22
+</dev/null $tmpDir/vm/bin/run-*-vm -m $vmMemoryMiB -smp $vmNumCPUs &>/dev/null &
+qemuPID=$!
+
+# Run command in VM
+c() {
+    ssh -p $sshPort -i $identityFile -o ConnectTimeout=1 \
+        -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=ERROR \
+        -o ControlMaster=auto -o ControlPath=$tmpDir/ssh-connection -o ControlPersist=60 \
+        root@127.0.0.1 "$@"
+}
+
+echo
+echo "Waiting for SSH connection..."
+while ! c : 2>/dev/null; do :; done
+
+echo
+echo "Waiting until services are ready..."
+c '
+attempts=300
+while ! systemctl is-active clightning &> /dev/null; do
+    ((attempts-- == 0)) && { echo "timeout"; exit 1; }
+    sleep 0.2
+done
+'
+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
+
+# Cleanup happens at exit (see above)

examples/qemu-vm/id-vm

@@ -0,0 +1,7 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAMwAAAAtzc2gtZW
+QyNTUxOQAAACBbda93/QYwDf4PGJp2KgJ1xwKPgKhEHeJrubXAeZWPpgAAAIgDA7dzAwO3
+cwAAAAtzc2gtZWQyNTUxOQAAACBbda93/QYwDf4PGJp2KgJ1xwKPgKhEHeJrubXAeZWPpg
+AAAECuRSsNFRQgAOid87b/2kIhgycAH5nPgZwkY4bUpq7LQFt1r3f9BjAN/g8YmnYqAnXH
+Ao+AqEQd4mu5tcB5lY+mAAAABG5vbmUB
+-----END OPENSSH PRIVATE KEY-----

examples/qemu-vm/id-vm.pub

@@ -0,0 +1 @@
+ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFt1r3f9BjAN/g8YmnYqAnXHAo+AqEQd4mu5tcB5lY+m none