Logging

Learn about logging features that help you debug your Jovo apps.

Introduction

The main logging feature provided by Jovo is Basic Logging, which logs the request and response of each interaction. This is especially relevant for debugging and support requests, for example in the Jovo Community Forum.

Most Jovo templates enable logging by default. You can find the configuration for this in the app.ts app configuration file:

const app = new App({
  logging: true,
  // ...
});

This default configuration will show the full request and response JSON objects in your logs. If you're developing locally, the logs are displayed in your terminal/command line. For other deployment environments, they show up in the respective log service, for example CloudWatch on AWS.

Jovo also offers an internal Logger that can be used for different log levels. Learn more in the Jovo Logger section.

Configuration

You can modify the logging configuration by turning logging: true into an object, like this:

new App({
  logging: {
    enabled: true,
    // ...
  },
  // ...
});

Here are all configurations:

logging: {
  enabled: true,
  request: { /* ... */ },
  response: { /* ... */ },
  maskValue: '[ Hidden ]',
  indentation: '  ',
  styling: true,
  colorizeSettings: { /* ... */ },
  logger: { /* ... */ },
},

Basic Logging

Basic logging is responsible for logging the the request and response of each interaction. Learn more about the lifecycle in the RIDR documentation.

Request Logging

You can specifically enable and disable the logging of requests with the following config:

logging: {
  request: true,
  // ...
},

For some platforms, the logs of a request can get quite long if you only need certain information. There are additional config properties to help you with this:

logging: {
  request: {
    enabled: true,
    objects: [],
    maskedObjects: [],
    excludedObjects: [],
  },
  // ...
},

objects can be used to only display the properties that are referenced as strings in the array. This can include nested objects. Here is an example:

logging: {
  request: {
    objects: [
    'request',
    'context.System.user'
    ],
  },
  // ...
},

In a similar fashion, you can also mask objects or completely remove them from the logs using excludedObjects.

Response Logging

You can specifically enable and disable the logging of responses with the following config:

logging: {
  response: true,
  // ...
},

Similar to request logging, you can use additional configurations to modify which elements should be displayed:

logging: {
  response: {
    enabled: true,
    objects: [],
    maskedObjects: [],
    excludedObjects: [],
  },
  // ...
},

Masking

As described in the request and response logging sections, you can add masking for specific request or response objects. This is helpful for sensitive data like access tokens or private user information that shouldn't be logged on a server or logging service like AWS Cloudwatch.

logging: {
  maskValue: '[ Hidden ]',
  request: {
    maskedObjects: [],
    // ...
  },
  response: {
    maskedObjects: [],
    // ...
  },
},

Instead of showing the object's content, the logs will display the maskValue, the default being [ Hidden ].

Styling

You can make changes to the log's styling with the following properties:

logging: {
  indentation: '   ',
  styling: true, // Enable or disable styling
  colorizeSettings: {
    colors: { // Change the display of colors
      STRING_KEY: 'white',
      STRING_LITERAL: 'green',
      NUMBER_LITERAL: 'yellow',
      BRACE: 'white.bold',
    },
  },
  // ...
},

Jovo Logger

Jovo has an internal Logger that can be used to display certain levels of logs. It uses loglevel and uses the levels described there.

You can modify the Logger by using the logger property in the logging config:

logging: {
  logger: {
    level: 'error' // Show error only
  },
  // ...
},

This is the default configuration for logger, simplified for readability:

{
  name: 'JovoLogger', // Name of the logger, see loglevel.getLogger
  level: process.env.JOVO_LOG_LEVEL || 'trace', // Level of the logger, see logLevel.setLevel
  styling: true, // Enable or disable styling completely 
  errorProperties: ['package', 'message', 'context', 'stack', 'hint', 'learnMore'], // Can be used to change order of error properties that are displayed or even omit some
}

You can use the logger to log to various log levels, which can be set in the config or using the environment variable JOVO_LOG_LEVEL, for example like this:

process.env.JOVO_LOG_LEVEL = 'warn';

You can also learn more about all errorProperties in the JovoError documentation.

You can import the Jovo Logger like this:

import { Logger } from '@jovotech/framework';

The logs can be done like this:

Logger.trace(string); // JOVO_LOG_LEVEL = 'trace'
Logger.log(string); // JOVO_LOG_LEVEL = 'debug'
Logger.debug(string); // JOVO_LOG_LEVEL = 'debug'
Logger.info(string); // JOVO_LOG_LEVEL = 'info'
Logger.warn(string); // JOVO_LOG_LEVEL = 'warn'
Logger.error(new Error()); // JOVO_LOG_LEVEL = 'error'

Additionally, setting the log level to 'silent' will cause no logs to be shown.

Learn more about log levels in the official loglevel documentation.