Backup LND SCB to S3 on change

closes #359

site-cookbooks/kosmos-bitcoin/recipes/lnd-scb-s3.rb

@@ -0,0 +1,47 @@
+#
+# Cookbook:: kosmos-bitcoin
+# Recipe:: lnd-scb-s3
+#
+# Static Channel Backup for LND channel states
+#
+
+include_recipe "kosmos-bitcoin::aws-client"
+
+package "inotify-tools"
+
+backup_script_path = "/opt/lnd-channel-backup-s3.sh"
+
+template backup_script_path do
+  source "lnd-channel-backup-s3.sh.erb"
+  mode '0740'
+  variables lnd_dir: node['lnd']['lnd_dir'],
+            bitcoin_network: node['bitcoin']['network'],
+            s3_bucket: node['backup']['s3']['bucket'],
+            s3_scb_dir: "#{node['name']}/lnd/#{node['bitcoin']['network']}"
+  notifies :restart, "systemd_unit[lnd-channel-backup.service]", :delayed
+end
+
+systemd_unit 'lnd-channel-backup.service' do
+  content({
+    Unit: {
+      Description: 'LND Static Channel Backup',
+      Documentation: ['https://gist.github.com/alexbosworth/2c5e185aedbdac45a03655b709e255a3'],
+      Requires: 'lnd.service',
+      After: 'lnd.service'
+    },
+    Service: {
+      User: 'root',
+      Group: 'root',
+      Type: 'simple',
+      ExecStart: backup_script_path,
+      Restart: 'always',
+      RestartSec: 1
+    },
+    Install: {
+      WantedBy: 'multi-user.target'
+    }
+  })
+  verify false
+  triggers_reload true
+  action [:create, :enable, :start]
+end

site-cookbooks/kosmos-bitcoin/templates/lnd-channel-backup-s3.sh.erb

@@ -0,0 +1,7 @@
+#!/bin/bash
+set -xe -o pipefail
+
+while true; do
+  inotifywait <%= @lnd_dir %>/data/chain/bitcoin/<%= @bitcoin_network %>/channel.backup
+  aws s3 cp <%= @lnd_dir %>/data/chain/bitcoin/<%= @bitcoin_network %>/channel.backup "s3://<%= @s3_bucket %>/<%= @s3_scb_dir %>/channel.backup"
+done