Configurable knot location

config.json.defaults

 {
 	"higherLevelDomain": "dyndns.mydomain.com",
+	"knotLocation": "/usr/sbin/knotc",
 	"dbHost": "localhost",
 	"listenAddress": "127.0.0.1",
 	"listenPort": 3000

knotdns.js

@@ -5,17 +5,17 @@ const config = require('./config');
 
 async function updateRecord(domain, ip) {
 	try {
-		await exec("/usr/sbin/knotc zone-begin " + config.config().higherLevelDomain);
+		await exec(config.config().knotLocation + " zone-begin " + config.config().higherLevelDomain);
 		try {
-			await exec("/usr/sbin/knotc zone-unset " + config.config().higherLevelDomain + " " + domain);
+			await exec(config.config().knotLocation + " zone-unset " + config.config().higherLevelDomain + " " + domain);
 		} catch {
 			console.log("Could not unset domain " + domain);
 		}
-		await exec("/usr/sbin/knotc zone-set " + config.config().higherLevelDomain + " " + domain + " 60 A " + ip);
-		await exec("/usr/sbin/knotc zone-commit " + config.config().higherLevelDomain);
+		await exec(config.config().knotLocation + " zone-set " + config.config().higherLevelDomain + " " + domain + " 60 A " + ip);
+		await exec(config.config().knotLocation + " zone-commit " + config.config().higherLevelDomain);
 	} catch {
 		try {
-			await exec("/usr/sbin/knotc zone-abort " + config.config().higherLevelDomain);
+			await exec(config.config().knotLocation + " zone-abort " + config.config().higherLevelDomain);
 			console.log("Problem with manipulating DNS zone " + config.config().higherLevelDomain + ". Aborted transaction.");
 		} catch {
 			console.log("Problem with manipulating DNS zone " + config.config().higherLevelDomain + ". Could not even abort transaction.");