# Logger

Ts.ED has its own logger available through @tsed/logger (opens new window) package.

# Features

Ts.ED logger supports many features, and is optimized to be used in production.

You can create your own layout/appender:

# Configuration

Logger can be configured through the Configuration decorator:

Props Description
logger.level Change the default log level displayed in the terminal. Values: debug, info, warn or error. By default: info.
logger.logRequest Log all incoming requests. By default, it's true and prints the configured logger.requestFields.
logger.requestFields Fields displayed when a request is logged. Possible values: reqId, method, url, headers, body, query,params, duration.
logger.reqIdBuilder A function called for each incoming request to create a request id.
logger.jsonIndentation The number of space characters to use as white space in JSON output. Default is 2 (0 in production).
logger.disableRoutesSummary Disable routes table displayed in the logger.
logger.format Specify log format. Example: %[%d{[yyyy-MM-dd hh:mm:ss,SSS}] %p%] %m. See @tsed/logger configuration (opens new window).
logger.ignoreUrlPatterns (String or RegExp) List of patterns to ignore logged request according to the request.url.

WARNING

It is recommended to disable logRequest in production. Logger has a cost on the performance.

# Use Json Layout in production

You add this code to switch the logger to Json layout in production mode:

import {env} from "@tsed/core";
import {$log, Configuration} from "@tsed/common";
import "@tsed/platform-express";

export const isProduction = process.env.NODE_ENV === Env.PROD;

if (isProduction) {
  $log.appenders.set("stdout", {
    type: "stdout",
    levels: ["info", "debug"],
    layout: {
      type: "json"
    }
  });
  $log.appenders.set("stderr", {
    levels: ["trace", "fatal", "error", "warn"],
    type: "stderr",
    layout: {
      type: "json"
    }
  });
}

@Configuration({
  logger: {
    disableRoutesSummary: isProduction // remove table with routes summary
  }
})
export class Server {}
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This configuration will display the log as following:

{"startTime":"2017-06-05T22:23:08.479Z","categoryName":"json-test","data":["this is just a test"],"level":"INFO","context":{}}
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It's more useful if you planed to parse the log with LogStash or any log tool parser.

# Inject logger

Logger can be injected in any injectable provider as follows:

import {Logger} from "@tsed/common";
import {Injectable, Inject} from "@tsed/di";

@Injectable()
export class MyService {
  @Inject()
  logger: Logger;
  
  $onInit() {
    this.logger.info('Hello world');
  }
}
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TIP

Prefer the RequestLogger usage if you want to attach your log the current request. See the next section.

# Request logger

For each Request, a logger will be attached to the PlatformContext and can be used like here:

import {Controller, Context, Get} from "@tsed/common";
import {Logger} from "@tsed/logger";
import {MyService} from "../services/MyService";

@Controller("/")
class MyController {
  @Inject()
  myService: MyService;

  @Get("/")
  get(@Context() ctx: Context) {
    ctx.logger.info({customData: "test"}); // parameter is optional
    ctx.logger.debug({customData: "test"});
    ctx.logger.warn({customData: "test"});
    ctx.logger.error({customData: "test"});
    ctx.logger.trace({customData: "test"});
   
    // forward ctx object to the service and use logger inside.
    // All request
    myService.doSomething("test", ctx);
  }
}
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import {PlatformContext} from "@tsed/common";
import {Injectable, Inject} from "@tsed/di";

@Injectable()
export class MyService {
  doSomething(input: string, ctx: PlatformContext) {
     ctx.logger.info({event: "test", input});
  }
}
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TIP

All log use through ctx.logger will be associated with the uniq request id generated by Ts.ED.

TIP

RequestLogger , in production mode, caches all request logs until the response is sent to your consumer.

A call with one of these methods will generate a log according to the logger.requestFields configuration:

[2017-09-01 11:12:46.994] [INFO ] [TSED] - {
  "status": 200,
  "reqId": 1,
  "method": "GET",
  "url": "/api-doc/swagger.json",
  "duration": 92,
  "headers": {
    "host": "0.0.0.0:8001",
    "connection": "keep-alive",
    "upgrade-insecure-requests": "1",
    "user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.101 Safari/537.36",
    "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8",
    "accept-encoding": "gzip, deflate",
    "accept-language": "fr-FR,fr;q=0.8,en-US;q=0.6,en;q=0.4"
  },
  "body": {},
  "query": {},
  "customData": "test"
}
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You can configure the displayed fields from the server configuration:

import {Configuration} from "@tsed/common";

@Configuration({
  logger: {
    requestFields: ["reqId", "method", "url", "headers", "body", "query","params", "duration"]
  }
})
export class Server {}
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or you can override the middleware with OverrideProvider .

Example:

import {Context, OverrideProvider, PlatformLogMiddleware} from "@tsed/common";

@OverrideProvider(PlatformLogMiddleware)
export class CustomPlatformLogMiddleware extends PlatformLogMiddleware {
  public use(@Context() ctx: Context) {
    // do something

    return super.use(ctx); // required
  }

  protected requestToObject(ctx: Context) {
    const {request} = ctx;

    // NOTE: request => PlatformRequest. To get Express.Request use ctx.getRequest<Express.Request>();
    return {
      method: request.method,
      url: request.url,
      headers: request.headers,
      body: request.body,
      query: request.query,
      params: request.params
    };
  }
}
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# Shutdown logger

Shutdown returns a Promise that will be resolved when @tsed/logger has closed all appenders and finished writing log events. Use this when your program exits to make sure all your logs are written to files, sockets are closed, etc.

import {$log} from "@tsed/logger";

$log
  .shutdown()
  .then(() => {
     console.log("Complete")
  });
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Last Updated: 1/25/2021, 12:25:46 PM

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