Introduce winston logger to replace the console logs

kabirbaidhya · Aug 8, 2016 · c9fa283 · c9fa283
1 parent 65efe97
commit c9fa283
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Showing 7 changed files with 41 additions and 22 deletions.
diff --git a/package.json b/package.json
@@ -33,6 +33,7 @@
     "lodash.debounce": "^4.0.6",
     "lodash.throttle": "^4.0.1",
     "pg": "^6.0.1",
+    "winston": "^2.2.0",
     "yamljs": "^0.2.8"
   },
   "devDependencies": {

diff --git a/src/Listener.js b/src/Listener.js
@@ -4,6 +4,7 @@ import {yellow, green, red, dim} from 'chalk';
 
 import {halt} from './program';
 import {log, error} from './util';
+import logger from './logging/logger';
 import * as msg from './messages/common';
 
 class Listener {
@@ -28,10 +29,10 @@ class Listener {
                 halt(err);
             }
 
-            log(msg.DATABASE_CONNECTED, yellow(connection.database));
+            logger.info(msg.DATABASE_CONNECTED, yellow(connection.database));
         });
 
-        client.on('notice', msg => log(msg));
+        client.on('notice', msg => logger.info(msg));
         client.on('notification', notification => this.handle(notification));
 
         channels.forEach(channel => this.listenTo(channel));
@@ -56,7 +57,7 @@ class Listener {
         const handlers = this.handlers[channel];
 
         if (!Array.isArray(handlers)) {
-            throw new Error(format(msg.NO_HANDLERS_FOUND, channel));
+            throw new Error(format(msg.WARN_NO_HANDLERS_FOUND, channel));
         }
 
         // TODO: Delegate CPU-intensive jobs to a task queue or a separate process.
@@ -68,7 +69,7 @@ class Listener {
         const database = this.client.database;
         const {channel, payload: str} = notification;
 
-        log(msg.RECEIVED_NOTIFICATION, green(database + ':' + channel), dim(str || '(empty)'));
+        logger.info(msg.RECEIVED_NOTIFICATION, green(database + ':' + channel), dim(str || '(empty)'));
 
         try {
             const payload = this.parsePayload(str);
@@ -84,11 +85,11 @@ class Listener {
         const database = this.client.database;
 
         this.client.query(`LISTEN ${channel}`).then(() => {
-            log(msg.STARTED_LISTENING, green(database + ':' + channel));
+            logger.info(msg.STARTED_LISTENING, green(database + ':' + channel));
 
             // Warn if handlers are not registered for the channels being listened to
             if (!Array.isArray(this.handlers[channel])) {
-                error(format(msg.NO_HANDLERS_FOUND, channel));
+                logger.warn(msg.WARN_NO_HANDLERS_FOUND, channel);
             }
         });
     }

diff --git a/src/logging/logger.js b/src/logging/logger.js
@@ -0,0 +1,14 @@
+import winston from 'winston';
+
+const formatter = (opts) => {
+    return `[${opts.level}] ${(opts.message || '')}` +
+        (opts.meta && Object.keys(opts.meta).length ? '\n\t' + JSON.stringify(opts.meta) : '' );
+};
+
+const logger = new (winston.Logger)({
+    transports: [
+        new winston.transports.Console({formatter})
+    ]
+});
+
+export default logger;
diff --git a/src/messages/common.js b/src/messages/common.js
@@ -1,10 +1,10 @@
-export const NO_HANDLERS_FOUND = 'Warning: No handlers are registered for channel "%s" yet.';
+export const WARN_NO_HANDLERS_FOUND = 'Warning: No handlers are registered for channel "%s" yet.';
 export const NO_CHANNELS_TO_LISTEN = 'No channels to LISTEN to';
 export const RECEIVED_NOTIFICATION = 'Received notification on channel %s: %s';
 export const DATABASE_CONNECTED = 'Connected to database %s';
 export const STARTED_LISTENING = 'Started listening to channel %s';
 export const SETUP_ERROR = 'Setup could not be completed.';
 export const GENERIC_ERROR_MESSAGE = 'An error occurred.';
-export const LOADED_CONFIG_FILE = 'Loaded configuration file: %s';
-export const ERROR_LOADING_CONFIG_FILE = 'Error loading configuration file: %s';
+export const LOADED_CONFIG_FILE = 'Loaded configuration file %s';
+export const ERROR_LOADING_CONFIG_FILE = 'Error loading configuration file %s';
 export const NO_CONNECTIONS_CONFIGURED = 'No database connections are configured. Please do configure properly and start pglistend again.';
diff --git a/src/program.js b/src/program.js
@@ -4,7 +4,8 @@ import prog from 'commander';
 import {spawnSync} from 'child_process';
 
 import Listener from './Listener';
-import {error} from './util';
+import {error, isString} from './util';
+import logger from './logging/logger';
 import * as msg from './messages/common';
 import {resolveConfig, resolveHandlers} from './resolver';
 
@@ -36,7 +37,7 @@ export function run() {
  * Note: Should be called only in case of fatal error.
  */
 export function halt(err) {
-    error(err || msg.GENERIC_ERROR_MESSAGE);
+    logger.error(isString(err) ? err : (err.message || msg.GENERIC_ERROR_MESSAGE));
     process.exit(1);
 }
 

diff --git a/src/query.js b/src/query.js
@@ -1,4 +1,5 @@
 import {log, error} from './util';
+import logger from './logging/logger';
 
 /**
  * @return {Promise}
@@ -10,7 +11,7 @@ export default function query(sql, values) {
                 let message = `Connection Error: ${err}`;
 
                 reject(message);
-                error(message);
+                logger.error(message);
 
                 return;
             }
@@ -22,12 +23,12 @@ export default function query(sql, values) {
                     let message = `Query error: ${err}`;
 
                     reject(message);
-                    error(message);
+                    logger.error(message);
 
                     return;
                 }
 
-                log('Executed query: ', sql);
+                logger.info('Executed query: ', sql);
                 resolve(result);
             });
         });

diff --git a/src/resolver.js b/src/resolver.js
@@ -4,10 +4,10 @@ import {yellow} from 'chalk';
 import deepAssign from 'deep-assign';
 
 import query from './query';
-import {log, error} from './util';
 import {throttle, debounce} from './util';
 import {isObject, isFunction} from './util';
 import * as msg from './messages/common';
+import logger from './logging/logger';
 
 export function resolveConfig(file) {
     let config = loadConfig(file);
@@ -27,10 +27,10 @@ function loadConfig(file) {
     try {
         let config = Yaml.load(file);
 
-        log(msg.LOADED_CONFIG_FILE, yellow(file));
+        logger.info(msg.LOADED_CONFIG_FILE, yellow(file));
         return config;
     } catch (e) {
-        error(msg.ERROR_LOADING_CONFIG_FILE, file);
+        logger.error(msg.ERROR_LOADING_CONFIG_FILE, file);
         throw e;
     }
 }
@@ -39,7 +39,7 @@ export function resolveHandlers(config) {
     let scripts = Array.isArray(config.scripts) ? config.scripts : [];
 
     if (scripts.length === 0) {
-        error('Warning: No listener scripts are configured.');
+        logger.warn('No listener scripts are configured.');
 
         return {};
     }
@@ -56,7 +56,8 @@ function getCallbackHelpers(config) {
     let pool = new Pool(config.connection);
 
     return {
-        log, error,
+        log: logger.info,
+        error: logger.error,
         throttle, debounce,
         query: query.bind(pool)
     };
@@ -65,7 +66,7 @@ function getCallbackHelpers(config) {
 function resolveHandlersFromFile(file, helpers) {
     let func = require(file);
 
-    if (!isFunction(require(file))) {
+    if (!isFunction(func)) {
         throw new Error(`Invalid listener script provided. The script file "${file}" should export a function.`);
     }
 
@@ -89,7 +90,7 @@ function resolveForScripts(scripts, helpers) {
                 let callback = handlers[key];
 
                 if (!isFunction(callback)) {
-                    error(`Invalid callback function specified for key "${key}" on file "${file}"`);
+                    logger.error(`Invalid callback function specified for key "${key}" on file "${file}"`);
 
                     continue;
                 }
@@ -101,7 +102,7 @@ function resolveForScripts(scripts, helpers) {
                 resolved[key].push(callback);
             }
         } catch (e) {
-            error(e.message);
+            logger.error(e.message);
         }
     });