Tramway Logger is a simple adapter to integrate logging modules with the Tramway core. It includes:

1. Various middleware for logging and handling errors in your application
2. A Logger shell that guarentees consistency regardless which logger library you use by integrating a Provider.

Installation:

1. npm install --save tramway-core-logger

Getting Started

Choose and install a logging plugin like tramway-logger-winston.

With dependency injection you can add the following entries to your services config files. Be sure to do the same with your plugin.

In this example, we set up everything that's needed for logging with winston in the src/config/services/logging.js file.

You can add any necessary parameters in the src/config/parameters/global directory.

import Logger, {middleware} from 'tramway-core-logger';

import {
    providers,
    transports,
} from 'tramway-logger-winston';

const {
    LoggerMiddlewareBuilder, 
    ErrorResponseMiddlewareBuilder,
    ErrorLoggerMiddlewareBuilder,
    NotFoundMiddlewareBuilder,
} = middleware;

const {WinstonProvider} = providers;
const {File, Console} = transports;

export default {
    "logger": {
        "class": Logger,
        "constructor": [
            {"type": "service", "key": "logger.provider.winston"},
        ],
    },
    "logger.provider.winston": {
        "class": WinstonProvider,
        "constructor": [
            {"type": "parameter", "key": "winston"},
        ], 
        "functions": [
            {
                "function": "addTransport", 
                "args": [
                    {"type": "service", "key": "transport.file:error"}
                ]
            },
            {
                "function": "addTransport", 
                "args": [
                    {"type": "service", "key": "transport.file:all"}
                ]
            },
            {
                "function": "addTransport", 
                "args": [
                    {"type": "service", "key": "transport.console"}
                ]
            },
        ]
    },
    "logger.middleware": {
        "class": LoggerMiddlewareBuilder,
        "constructor": [
            {"type": "service", "key": "logger.middleware.not.found"},
            {"type": "service", "key": "logger.middleware.error.logger"},
            {"type": "service", "key": "logger.middleware.error.response"},
        ],
    },
    "logger.middleware.error.response": {
        "class": ErrorResponseMiddlewareBuilder,
        "constructor": [
            {"type": "service", "key": "logger"}
        ],
    },
    "logger.middleware.error.logger": {
        "class": ErrorLoggerMiddlewareBuilder,
        "constructor": [
            {"type": "service", "key": "logger"}
        ],
    },
    "logger.middleware.not.found": {
        "class": NotFoundMiddlewareBuilder,
        "constructor": [
            {"type": "service", "key": "logger"}
        ],
    },
    "transport.file:error": {
        "class": File,
        "constructor": [
            {"type": "parameter", "key": "file_error"}
        ],
    },
    "transport.file:all": {
        "class": File,
        "constructor": [
            {"type": "parameter", "key": "file_all"}
        ],
    },
    "transport.console": {
        "class": Console,
        "constructor": [
            {"type": "parameter", "key": "console_all"}
        ]
    },
};

Update your core services to add the logger builder to your App configuration. Notice we use the middleware since the application example uses Express.js.

import {
    App,
} from 'tramway-core';

export default {
    "app": {
        "class": App,
        "constructor": [
            {"type": "service", "key": "router"},
            {"type": "parameter", "key": "app"},
            {"type": "parameter", "key": "port"}
        ],
        "functions": [
            {
                "function": "use",
                "args": [
                    {"type": "parameter", "key": "cors"}
                ]
            },
            {
                "function": "addLogger",
                "args": [
                    {"type": "service", "key": "logger.middleware"}
                ]
            },
            
        ]
    },
};

Configuration

For various middleware, you can configure certain functionalities in the parameters and pass them as objects to the config argument in the respective constructors.

ErrorLoggerMiddlewareBuilder and NotFoundMiddlewareBuilder

transformIp is a function taking an ip and returning a modified version of it. Essential for GDPR compliance.

Example:

In your parameters:

error_logger.js:

export default {
    transformIp: ip => null //don't save ips at all
}

Make sure this file is part of the index.js file in the same directory

import error_logger from './error_logger';
export {
    error_logger,
}

In the logging service configuration that contains your middleware:

"logger.middleware.error.logger": {
    "class": ErrorLoggerMiddlewareBuilder,
    "constructor": [
        {"type": "service", "key": "logger"},
        {"type": "parameter", "key": "error_logger"},
    ],
},

ErrorResponseMiddlewareBuilder

displayedEnvironments is an array of environments that will be checked against the one of the machine. The middleware will automatically remove error messages from display in environments that aren't specified.

Example:

In your parameters:

error_response.js:

export default {
    displayEnvironments: ['development']
}

Make sure this file is part of the index.js file in the same directory

import error_response from './error_response';
export {
    error_response,
}

In the logging service configuration that contains your middleware:

"logger.middleware.error.response": {
    "class": ErrorResponseMiddlewareBuilder,
    "constructor": [
        {"type": "service", "key": "logger"},
        {"type": "parameter", "key": "error_response"},
    ],
},