migrate blocklist to a txt file

this allows easy copy/pasting of existing deny lists which contain
comments and blank lines

migrations/20200914172345-split-firewall-config.js

@@ -0,0 +1,27 @@
+'use strict';
+
+const OLD_FIREWALL_CONFIG_JSON = '/home/yellowtent/boxdata/firewall-config.json';
+const PORTS_FILE = '/home/yellowtent/boxdata/firewall/ports.json';
+const BLOCKLIST_FILE = '/home/yellowtent/boxdata/firewall/blocklist.txt';
+
+const fs = require('fs');
+
+exports.up = function (db, callback) {
+    if (!fs.existsSync(OLD_FIREWALL_CONFIG_JSON)) return callback();
+
+    try {
+        const dataJson = fs.readFileSync(OLD_FIREWALL_CONFIG_JSON, 'utf8');
+        const data = JSON.parse(dataJson);
+        fs.writeFileSync(BLOCKLIST_FILE, data.blocklist.join('\n') + '\n', 'utf8');
+        fs.writeFileSync(PORTS_FILE, JSON.stringify({ allowed_tcp_ports: data.allowed_tcp_ports }, null, 4), 'utf8');
+        fs.unlinkSync(OLD_FIREWALL_CONFIG_JSON);
+    } catch (error) {
+        console.log('Error migrating old firewall config', error);
+    }
+
+    callback();
+};
+
+exports.down = function (db, callback) {
+    callback();
+};