strapi/docs/3.0.0-alpha.x/advanced/logging.md

Logging

Strapi relies on an extremely fast Node.js logger called Pino that includes a shell utility to pretty-print its log files. It provides great performances and doesn't slow down your app. The logger is accessible through the global variable strapi.log or the request's context ctx.log if enabled.

// Folder.js controller
const fs = require('fs');
const path = require('path');

module.exports = {

  /**
   * Retrieve app's folders.
   *
   * @return {Object|Array}
   */

  findFolders: async (ctx) => {
    try {
      const folders = fs.readdirSync(path.resolve(process.cwd()));

      strapi.log.info(folders); // ctx.log.info(folders);

      ctx.send(folders);
    } catch (error) {
      strapi.log.fatal(error); // ctx.log.fatal(error);
      ctx.badImplementation(error.message);
    }
  }
}

Global logger configuration

The global logger is configured by environment variables.

• STRAPI_LOG_LEVEL: Can be fatal, error, warn, info, debug or trace.
• STRAPI_LOG_TIMESTAMP: Can be true/false
• STRAPI_LOG_PRETTY_PRINT: Can be true/false
• STRAPI_LOG_FORCE_COLOR: Can be true/false

Request logging middleware

To configure the request-logger middleware, you have to edit the following file ./config/environments/*/request.json.

{
  ...
  "logger": {
    "level": "debug",
    "exposeInContext": true,
    "requests": true
  },
  ...
}

• level: defines the desired logging level (fatal, error, warn, info, debug, trace).
• exposeInContext: allows access to the logger through the context.
• requests: incoming HTTP requests will be logged.

To find more details about the logger API, please refer to the Pino documentation.