feat: Provide a logger instance by default

Create a logger instance by default and retrieve its settings from environment variables.

BREAKING_CHANGE

Author: ikhemissi

README.md

@@ -10,7 +10,20 @@ npm install --save @5app/logger
 Then, generate a logger in your app and use it to log messages.
 
 ```javascript
-const getLogger = require('@5app/logger');
+const {logger} = require('@5app/logger');
+
+logger.info('An email was sent', {
+  email: 'customer@5app.com',
+  template: 'template1',
+});
+
+logger.error(new Error('Unknown playlist 123'));
+```
+
+Alternatively, you can create a new instance of logger where you can specify the metadata, logging level, and whether you want simple logs or not:
+
+```javascript
+const {getLogger} = require('@5app/logger');
 
 const logger = getLogger({
   simple: process.env.NODE_ENV === 'development',
@@ -38,29 +51,48 @@ By default, simple will be false.
 
 Example:
 ```javascript
-const getLogger = require('@5app/logger');
+const {getLogger} = require('@5app/logger');
 
 // This logger will log dev-friendly messages
 const logger = getLogger({
   simple: true,
 });
 ```
 
+The default logger uses the environment variable `LOGS_FORMAT` to determine if the logs are going to be generated in json (`json`) or simple console logs (any other value other than `json`).
+
 ### metadata
 
 Metadata is an object containing service metadata like the release tag or the A/B testing experiment we are running.
 This object will be added to each log entry when using the JSON mode.
 
 Example:
 ```javascript
-const getLogger = require('@5app/logger');
+const {getLogger} = require('@5app/logger');
 
 // This logger will add details about the current release and A/B experiment to every log line
-const getLogger = require('@5app/logger');
 const logger = getLogger({
   metadata: {
     release: '1.2.3',
     experiment: 12345,
   },
 });
 ```
+
+### level
+
+You can specify a minimum logging level using the `level` parameter or using the `LOGS_LEVEL` environment variable.
+By default, the logging level will be [debug (npm)](https://github.com/winstonjs/winston#logging-levels).
+
+Example:
+```javascript
+const {getLogger} = require('@5app/logger');
+
+// This logger will add details about the current release and A/B experiment to every log line
+const logger = getLogger({
+  level: 'warn',
+});
+
+logger.info('this message will not be logged');
+logger.warn('you will see this message');
+```

getLogger.js

@@ -0,0 +1,44 @@
+const winston = require('winston');
+
+const LEVEL = Symbol.for('level');
+const {format} = winston;
+const sqlFormat = {
+	level: winston.config.npm.levels.debug,
+	color: 'grey'
+};
+
+winston.addColors({sql: sqlFormat.color});
+
+const colorizer = format.colorize();
+const sqlFormatter = format((info, opts) => {
+	const level = info[LEVEL];
+
+	if (opts.colorize && level === 'sql') {
+		info.message = colorizer.colorize(level, `${info.message}\n`);
+	}
+
+	return info;
+});
+
+function getFormatter({simple}) {
+	if (simple) {
+		return format.combine(format.splat(), format.colorize(), sqlFormatter({colorize: true}), format.simple());
+	}
+
+	return format.combine(format.splat(), format.timestamp(), format.json());
+}
+
+function getLogger({simple, level, metadata}) {
+	return winston.createLogger({
+		level,
+		levels: {
+			...winston.config.npm.levels,
+			sql: sqlFormat.level
+		},
+		format: getFormatter({simple}),
+		defaultMeta: metadata,
+		transports: [new winston.transports.Console()]
+	});
+}
+
+module.exports = getLogger;

index.js

@@ -1,44 +1,20 @@
-const winston = require('winston');
-
-const LEVEL = Symbol.for('level');
-const {format} = winston;
-const sqlFormat = {
-	level: winston.config.npm.levels.debug,
-	color: 'grey'
-};
-
-winston.addColors({sql: sqlFormat.color});
-
-const colorizer = format.colorize();
-const sqlFormatter = format((info, opts) => {
-	const level = info[LEVEL];
-
-	if (opts.colorize && level === 'sql') {
-		info.message = colorizer.colorize(level, `${info.message}\n`);
+const getLogger = require('./getLogger');
+
+const {
+	LOGS_FORMAT,
+	LOGS_LEVEL,
+	TAG
+} = process.env;
+
+const logger = getLogger({
+	simple: LOGS_FORMAT !== 'json',
+	level: LOGS_LEVEL || 'debug',
+	metadata: {
+		tag: TAG
 	}
-
-	return info;
 });
 
-function getFormatter({simple}) {
-	if (simple) {
-		return format.combine(format.splat(), format.colorize(), sqlFormatter({colorize: true}), format.simple());
-	}
-
-	return format.combine(format.splat(), format.timestamp(), format.json());
-}
-
-function getLogger({simple, metadata}) {
-	return winston.createLogger({
-		level: simple ? 'debug' : 'info',
-		levels: {
-			...winston.config.npm.levels,
-			sql: sqlFormat.level
-		},
-		format: getFormatter({simple}),
-		defaultMeta: simple ? {} : metadata,
-		transports: [new winston.transports.Console()]
-	});
-}
-
-module.exports = getLogger;
+module.exports = {
+	logger,
+	getLogger
+};