Log

The Log library abstracts away much of the logging functionality, making it so that with one call, log statements get logged in multiple places.

Usage

npm install @leverege/log --save

By default, the log defaults to the EmptyLog, which no-ops all logging methods. To install a console logger, in the main class call:

const log = require( '@leverege/log' );
log.setAdapter( log.ConsoleLog() )

To install a bunyan logger, call:

const bunyanLog = bunyan.createLogger( { ... } );
log.setAdapter( log.BunyanLog( bunyanLog ) );

Automated Log Creation and Installation

If you want to install a log entirely from a configuration variable (JSON, file, or plain object) call:

log.createAdapter(<config - object, JSON string, or file>, <params - object>, <install - boolean>)

This function will create an Adapter based on your configuration, can parameterize your configuration if you are using a string or file, and will automatically call setAdapter if install is not false.

a configuration may look like:

const logFile = '/var/config/transponder/logConfig.json'

or

const logString = '{
    "type" : "bunyan",
    "name" : "${logName}",
    "streams" : [
        { 
            "type" : "rotating-file",
            "period" : "1d",
            "count" : 3,
            "level" : "warn",
            "path" : "./logs3/${logName}"
        }, 
        { 
            "type" : "stackdriver",
            "logName" : "${resource}",
            "keyFilename" : "${logServiceAccount}"
        }
    ]
}'

or

const logObject = {
    type: 'console',
    mod: 'transponder'
}

In order to make the second JSON string configuration work, a parameters object would be supplied like so:

const logParams = {
    logName: ClusterManager.logName( 'transponder' ),
    resource: `transponder-${process.env.TRANSPONDER_RUN_MODE || 'all'}`,
    logServiceAccount: process.env.LOG_SERVICE_ACCOUNT
}

So the installation would look like the following:

log.createAdapter(logString, params, true)

Sensitive Information

In order to not log sensitive information (e.g. auth token, password), pass in "blacklist": true as an option parameter.

const logConfig = '{
    "type" : "bunyan",
    "name" : "${logName}",
    "blacklist" : true, 
    "streams" : [...]
}'

It will then omit those fields before outputing to log aggregater (e.g. Stackdriver).

Logging

To log, call:

const log = require( '@leverege/log' );
log.trace( 'trace log' );
log.debug( 'debug log' );
log.info( 'info log' );
log.warn( 'warn log' );
log.fatal( 'fatal log' );

The log methods can take an object as the first argument. See bunyans log for more information.

Other methods include:

child, setLevel, getLevel, isTrace, isDebug, isInfo, isWarn, isError, isError, isFatal