feat: add getLogger to app and ctx

it can be override with custom logical

Closes #36

app/extend/context.js

@@ -7,13 +7,12 @@ const Cookies = require('egg-cookies');
 const co = require('co');
 const util = require('../../lib/core/util');
 
-const LOGGER = Symbol('LOGGER');
-const CORE_LOGGER = Symbol('CORE_LOGGER');
 const HELPER = Symbol('Context#helper');
 const VIEW = Symbol('Context#view');
 const LOCALS = Symbol('Context#locals');
 const LOCALS_LIST = Symbol('Context#localsList');
 const COOKIES = Symbol('Context#cookies');
+const CONTEXT_LOGGERS = Symbol('Context#logger');
 
 const proto = module.exports = {
   get cookies() {
@@ -183,39 +182,51 @@ const proto = module.exports = {
   },
 
   /**
-   * 应用 Web 相关日志，用于记录 Web 行为相关的日志，
-   * 最终日志文件输出到 `{log.dir}/{app.name}-web.log` 中。
-   * 每行日志会自动记录上当前请求的一些基本信息，
-   * 如 `[$logonId/$userId/$ip/$timestamp_ms/$sofaTraceId $use_ms $method $url]`
+   * Wrap app.loggers with context infomation,
+   * if a custom logger is defined by naming aLogger, then you can `ctx.getLogger('aLogger')`
+   * @param {String} name - logger name
+   * @return {Logger} logger
+   */
+  getLogger(name) {
+    let cache = this[CONTEXT_LOGGERS];
+    if (!cache) {
+      cache = this[CONTEXT_LOGGERS] = {};
+    }
+
+    // read from cache
+    if (cache[name]) return cache[name];
+
+    // get no exist logger
+    const appLogger = this.app.getLogger(name);
+    if (!appLogger) return null;
+
+    // write to cache
+    cache[name] = new ContextLogger(this, appLogger);
+    return cache[name];
+  },
+
+  /**
+   * Logger for Application, wrapping app.coreLogger with context infomation
    * @member {ContextLogger} Context#logger
    * @since 1.0.0
    * @example
    * ```js
    * this.logger.info('some request data: %j', this.request.body);
    * this.logger.warn('WARNING!!!!');
    * ```
-   * 错误日志记录，直接会将错误日志完整堆栈信息记录下来，并且输出到 `{log.dir}/common-error.log`
-   * ```
-   * this.logger.error(err);
-   * ```
    */
   get logger() {
-    if (!this[LOGGER]) {
-      this[LOGGER] = new ContextLogger(this, this.app.logger);
-    }
-    return this[LOGGER];
+    return this.getLogger('logger');
   },
 
   /**
-   * app context 级别的 core logger，适合 core 对当前请求记录日志使用
+   * Logger for frameworks and plugins,
+   * wrapping app.coreLogger with context infomation
    * @member {ContextLogger} Context#coreLogger
    * @since 1.0.0
    */
   get coreLogger() {
-    if (!this[CORE_LOGGER]) {
-      this[CORE_LOGGER] = new ContextLogger(this, this.app.coreLogger);
-    }
-    return this[CORE_LOGGER];
+    return this.getLogger('coreLogger');
   },
 
   /**

lib/egg.js

@@ -154,9 +154,7 @@ class EggApplication extends EggCore {
   }
 
   /**
-   * logger 集合，包含两个：
-   *  - 应用使用：loggers.logger
-   *  - 框架使用：loggers.coreLogger
+   *  All loggers contain logger, coreLogger and customLogger
    * @member {Object}
    * @since 1.0.0
    */
@@ -167,13 +165,23 @@ class EggApplication extends EggCore {
     return this[LOGGERS];
   }
 
+  /**
+   * Get logger by name, it's equal to app.loggers['name'],
+   * but you can extend it with your own logical.
+   * @param {String} name - logger name
+   * @return {Logger} logger
+   */
+  getLogger(name) {
+    return this.loggers[name] || null;
+  }
+
   /**
    * 同 {@link Agent#coreLogger} 相同
    * @member {Logger}
    * @since 1.0.0
    */
   get logger() {
-    return this.loggers.logger;
+    return this.getLogger('logger');
   }
 
   /**
@@ -182,7 +190,7 @@ class EggApplication extends EggCore {
    * @since 1.0.0
    */
   get coreLogger() {
-    return this.loggers.coreLogger;
+    return this.getLogger('coreLogger');
   }
 
   _unhandledRejectionHandler(err) {

test/app/extend/application.test.js

@@ -5,6 +5,7 @@ const mm = require('egg-mock');
 const utils = require('../../utils');
 
 describe('test/app/extend/application.test.js', () => {
+
   describe('app.logger', () => {
     let app;
     before(() => {
@@ -16,6 +17,18 @@ describe('test/app/extend/application.test.js', () => {
     it('should alias app.logger => app.loggers.logger', () => {
       app.logger.should.equal(app.loggers.logger);
     });
+
+    it('should alias app.coreLooger => app.loggers.coreLooger', () => {
+      app.coreLogger.should.equal(app.loggers.coreLogger);
+    });
+
+    it('should alias app.getLogger(\'coreLogger\') => app.loggers.coreLooger', () => {
+      app.getLogger('coreLogger').should.equal(app.loggers.coreLogger);
+    });
+
+    it('should alias app.getLogger(\'noexist\') => null', () => {
+      (app.getLogger('noexist') === null).should.be.true();
+    });
   });
 
   describe('app.inspect()', () => {

test/app/extend/context.test.js

@@ -100,6 +100,30 @@ describe('test/app/extend/context.test.js', () => {
     });
   });
 
+  describe('ctx.getLogger', () => {
+    let app;
+    before(() => {
+      app = utils.app('apps/get-logger');
+      return app.ready();
+    });
+    after(() => app.close());
+
+    it('should return null when logger is not found', () => {
+      return request(app.callback())
+      .get('/noExistLogger')
+      .expect('null');
+    });
+
+    it('should log with padding message', function* () {
+      yield request(app.callback())
+      .get('/logger')
+      .expect(200);
+
+      const logPath = utils.getFilepath('apps/get-logger/logs/get-logger/a.log');
+      fs.readFileSync(logPath, 'utf8').should.match(/\[-\/127.0.0.1\/-\/\d+ms GET \/logger\] aaa/);
+    });
+  });
+
   describe('properties', () => {
     let app;
     before(() => {

test/fixtures/apps/get-logger/app/router.js

@@ -0,0 +1,12 @@
+'use strict';
+
+module.exports = function(app) {
+  app.get('/logger', function* () {
+    this.getLogger('aLogger').info('aaa');
+    this.body = 'done';
+  });
+
+  app.get('/noExistLogger', function* () {
+    this.body = this.app.getLogger('noexist') + '';
+  });
+};

test/fixtures/apps/get-logger/config/config.js

@@ -0,0 +1,13 @@
+'use strict';
+
+const path = require('path');
+
+module.exports = appInfo => {
+  return {
+    customLogger: {
+      aLogger: {
+        file: path.join(appInfo.baseDir, 'logs', appInfo.name, 'a.log'),
+      },
+    },
+  };
+};

test/fixtures/apps/get-logger/package.json

@@ -0,0 +1,3 @@
+{
+  "name": "get-logger"
+}