Added debug/logging feature

HOSTING.md

@@ -29,6 +29,8 @@ This guide will walk you through the process of setting up your own instance of
 `HOME_DOMAIN` | The host to enable `/stat` endpoint
 `USE_LOCAL_DNS` | Default is `false`, so the Google DNS is used. Set it to `true` if you want to use the DNS resolver of your own host
 `CACHE_EXPIRY_SECONDS` | Option to override the default cache TTL of 86400 seconds (1 day)
+`DEBUG_MODE` | Default is `false`; set to true to enable debug mode. Messages will be shown in the console
+`DEBUG_LEVEL` | Default level is 1 and can be set up to level 3 for maximum information
 
 If `WHITELIST_HOSTS` is set, `BLACKLIST_HOSTS` is ignored. Both is mutually exclusive.
 

src/client.js

@@ -12,6 +12,7 @@ import {
     validateCAARecords,
     isExceedHostLimit,
     isHttpCodeAllowed,
+    debugOutput,
     getExpiryDate
 } from "./util.js";
 
@@ -108,6 +109,7 @@ const listener = async function (req, res) {
             res.write('Host header is required');
             return;
         }
+        debugOutput(1, `Received HTTP request for ${host}`);
         if (host === process.env.HOME_DOMAIN) {
             // handle CORS
             res.setHeader('Access-Control-Allow-Origin', '*');
@@ -141,6 +143,7 @@ const listener = async function (req, res) {
                         totalSize += chunk.length;
                         // Disconnect if the data stream is too large
                         if (totalSize > MAX_DATA_SIZE) {
+                            debugOutput(3, `Data stream for request ${host} too large`);
                             req.destroy();
                             return;
                         }
@@ -162,6 +165,7 @@ const listener = async function (req, res) {
                                 if (cacheExists) {
                                     // Remove the cache entry
                                     resolveCache.delete(domain);
+                                    debugOutput(1, `Cache cleared for ${domain}`);
                                 }
                             }
                         }
@@ -176,7 +180,10 @@ const listener = async function (req, res) {
         if (!cache || (Date.now() > cache.expire)) {
             cache = await buildCache(host);
             resolveCache.set(host, cache);
-        }
+            debugOutput(1, `No cache found for ${host}, storing new data`);
+        } else {
+            debugOutput(1, `Found cache for ${host}, using stored data`);
+	    }
         if (cache.blacklisted) {
             if (blacklistRedirectUrl) {
                 res.writeHead(302, {
@@ -208,4 +215,4 @@ export {
     listener,
     pruneCache,
     buildCache,
-}
+}

src/util.js

@@ -35,6 +35,14 @@ let whitelistMap = null;
  * @type {number | null}
  */
 let cacheExpirySeconds = null;
+/**
+ * @type {boolean | null}
+ */
+let debugMode = null
+/**
+ * @type {number | null}
+ */
+let debugLevel = null
 
 export function getExpiryDate() {
     if (cacheExpirySeconds === null) {
@@ -96,6 +104,8 @@ export function clearConfig() {
     useLocalDNS = null;
     blacklistRedirectUrl = null;
     cacheExpirySeconds = null;
+    debugMode = null;
+    debugLevel = null;
 }
 
 /**
@@ -138,6 +148,51 @@ export function isHostBlacklisted(domain = '', mockEnv = undefined) {
     }
 }
 
+/**
+ * Returns the current date and time in the format: "YYYY-MM-DD HH:MM:SS".
+ *
+ * @returns {string} The current date and time as a formatted string.
+ */
+export function CurrentDate() {
+    const now = new Date();
+
+    return (
+        now.getFullYear() + '-' +
+        String(now.getMonth() + 1).padStart(2, '0') + '-' +
+        String(now.getDate()).padStart(2, '0') + ' ' +
+        String(now.getHours()).padStart(2, '0') + ':' +
+        String(now.getMinutes()).padStart(2, '0') + ':' +
+        String(now.getSeconds()).padStart(2, '0')
+    );
+}
+
+/**
+ * Outputs debug messages to the console based on the specified debug level.
+ * Debugging is controlled by the `DEBUG_MODE` and `DEBUG_LEVEL` environment variables.
+ *
+ * @param {number} level - The debug level of the message (1 - 3).
+ * @param {string} msg - The debug message to output.
+ * 
+ */
+export function debugOutput(level,msg) {
+   if (debugMode === null) {
+     debugMode = process.env.DEBUG_MODE == 'true';
+   }
+   if (debugLevel === null) {
+     debugLevel = process.env.DEBUG_LEVEL || 1;
+   }
+   if (debugMode) {
+     const date = CurrentDate();
+     if (level === 1 && debugLevel === 1 ) {
+ 	   console.log(`[${date}] ${msg}`);
+     } else if (level <= 2 && debugLevel <= 2 ) {
+ 	   console.log(`[${date}] ${msg}`);
+     } else if (level <=3 & debugLevel <= 3) {
+ 	   console.log(`[${date}] ${msg}`);
+     }
+   }
+}
+
 /**
  * @param {string} host
  */
@@ -201,6 +256,7 @@ const parseTxtRecordData = (value) => {
 export async function validateCAARecords(host, mockResolve = undefined) {
     if (useLocalDNS === null) {
         useLocalDNS = process.env.USE_LOCAL_DNS == 'true';
+	debugOutput(3, `useLocalDNS: ${useLocalDNS}`);
     }
     let issueRecords;
     if (useLocalDNS && !mockResolve) {
@@ -226,6 +282,7 @@ export async function validateCAARecords(host, mockResolve = undefined) {
         return null;
     }
 
+    debugOutput(3, `issueRecords for ${host}: ${issueRecords}`);
     return issueRecords;
 }
 
@@ -247,6 +304,7 @@ export async function findTxtRecord(host, mockResolve = undefined) {
         const resolved = await Promise.any(resolvePromises).catch(() => null);
 
         if (resolved) {
+	    debugOutput(2, `findTxtRecord for ${host}: ${resolved}`);
             for (const record of resolved) {
                 const joinedRecord = record.join(';');
                 const txtData = parseTxtRecordData(joinedRecord);
@@ -271,6 +329,7 @@ export async function findTxtRecord(host, mockResolve = undefined) {
             }
             const txtData = parseTxtRecordData(head.data);
             if (!txtData[recordParamDestUrl]) continue;
+            debugOutput(2, `findTxtRecord for ${host}: ${txtData[recordParamDestUrl]}`);
             return {
                 url: txtData[recordParamDestUrl],
                 httpStatus: txtData[recordParamHttpStatus],
@@ -286,6 +345,7 @@ export async function findTxtRecord(host, mockResolve = undefined) {
  */
 export function getCertExpiry(cert) {
     const x509 = forge.pki.certificateFromPem(cert);
+    debugOutput(3, `LE cert expire after: ${x509.validity.notAfter.getTime()}`);
     return x509.validity.notAfter.getTime()
 }
 
@@ -337,4 +397,4 @@ export function combineURLs(baseURL, relativeURL) {
  */
 export function isMainProcess(metaURL) {
     return [process.argv[1], process.env.pm_exec_path].includes(fileURLToPath(metaURL));
-}
+}