A simple logger for node applications. Logs to console, papertrail (via token) and Azure Function.
npm install --save @vtfk/logger
[!IMPORTANT]
Version 5.x.x and above requires Nodejs 16 or higher
All options are optional.
Logging to papertrail can be configured in logConfig()
or as env variables.
Logging to Microsoft Teams can be configured in logConfig()
or as env variable TEAMS_WEBHOOK_URL.
Azure Function logging can be configured in logConfig()
.
Note:
logConfig()
can be called multiple times to update the config throughout the program. And it will keep the previous config parameter if not specified in the next call.
const options = {
remote: { // Options for remote logging.
disabled: false, // If true; disables logging to remote, even if remote config is set
onlyInProd: true, // If true; only log to remote aggregator when NODE_ENV === 'production' (default is true)
host: '', // Host for the remote aggregator
token: '', // Token for the remote aggregator
level: '' // Lowest level for log to remote. If not set, all levels will log to remote
},
teams: { // Options for Microsoft Teams logging with webhook.
disabled: false, // If true; disables logging to Microsoft Teams, even if teams config is set
onlyInProd: true, // If true; only log to Microsoft Teams when NODE_ENV === 'production' (default is true)
url: '', // Microsoft Teams channel webhook url
level: '' // Lowest level for log to Microsoft Teams. If not set, all levels will log to Microsoft Teams
},
azure: { // Options for Azure
context: context, // The context object received from an Azure Function (see example further down)
excludeInvocationId: false // If true; do not append the invocationId from the context object
},
prefix: '', // A string that will be added in front of each log message (ex. UID for each run)
suffix: '', // A string that will be added at the end of each log message
error: { // Options for logging out Error object. If undefined; stack from Error object will be returned
useMessage: true // If true; use message from Error object instead of stack
},
localLogger: console.log // Replace the local logger with a custom function (Default: console.log)
}
logConfig(options)
NODE_ENV=production
PAPERTRAIL_HOST = papertrail.example.com/v1/log
PAPERTRAIL_TOKEN = jvkuvuyoufyofo8ygo8f609fo7ouyvcio7=
TEAMS_WEBHOOK_URL = https://<tenant>.webhook.office.com/blablabla
logConfig()
options take priority.
How to get Microsoft Teams Webhook URL
The least amount of code to log to console or a remote aggregator (if options are set in enviroment variables)
const { logger } = require('@vtfk/logger')
logger('info', ['test', 'message'])
The least amount of code to log to console or a remote aggregator asynchronous (if options are set in enviroment variables)
const { logger } = require('@vtfk/logger')
await logger('info', ['test', 'message'])
Use logConfig to instruct that message property is used from Error objects
const { logConfig, logger } = require('@vtfk/logger')
logConfig({
error: {
useMessage: true
}
})
logger('info', ['test', 'message'])
logger('warn', ['another', 'action', new Error('Ups. Something happend')])
// OUTPUT
// NAME-OF-APP and VER-OF-APP is the value of "name" and "version" in your package.json
[ 2019.05.19 15:41:17 ] < INFO > {NAME-OF-APP} - {VER-OF-APP}: test - message
[ 2019.05.19 15:41:17 ] < WARN > {NAME-OF-APP} - {VER-OF-APP}: another - action - Ups. Something happend
const { logger } = require('@vtfk/logger')
logger('info', ['test', 'message'])
logger('warn', ['another', 'action', new Error('Ups. Something happend')])
// OUTPUT
// NAME-OF-APP and VER-OF-APP is the value of "name" and "version" in your package.json
[ 2019.05.19 15:41:17 ] < INFO > {NAME-OF-APP} - {VER-OF-APP}: test - message
[ 2019.05.19 15:41:17 ] < WARN > {NAME-OF-APP} - {VER-OF-APP}: another - action - Error: Ups. Something happend\n
Use logConfig to display a UID infront of each message
const { logConfig, logger } = require('@vtfk/logger')
const nanoid = require('nanoid')
logConfig({
prefix: nanoid()
})
logger('info', ['test', 'message'])
logger('warn', ['another', 'action'])
// OUTPUT
// NAME-OF-APP and VER-OF-APP is the value of "name" and "version" in your package.json
[ 2019.05.19 15:41:17 ] < INFO > {NAME-OF-APP} - {VER-OF-APP}: V01k3pDpHCBkAHPyCvOOl - test - message
[ 2019.05.19 15:41:17 ] < WARN > {NAME-OF-APP} - {VER-OF-APP}: V01k3pDpHCBkAHPyCvOOl - another - action
module.exports = async function (context, req) {
logger('info', ['New Request. Validating token'], context) // This will log to context instead of using console.log (it will still display)
}
Configuration of remote options in the logConfig()
function
const { logConfig, logger } = require('@vtfk/logger')
// logConfig() is optional
logConfig({
remote: {
onlyInProd: true,
host: 'papertrail.example.com/v1/log',
token: 'jvkuvuyoufyofo8ygo8f609fo7ouyvcio7='
},
teams: {
url: 'https://<tenant>.webhook.office.com/blablabla'
}
prefix: 'prefixedValue',
suffix: 'suffixedValue'
})
logger('info', ['test', 'message'])
const error = Error('Error in process')
logger('error', ['Error in app', error])
// OUTPUT
// NAME-OF-APP and VER-OF-APP is the value of "name" and "version" in your package.json
[ 2019.05.19 15:13:35 ] < INFO > {NAME-OF-APP} - {VER-OF-APP}: prefixedValue - test - message - suffixedValue
[ 2019.05.19 15:13:35 ] < ERROR > {NAME-OF-APP} - {VER-OF-APP}: prefixedValue - Error in app - Error: Error in process - suffixedValue
Configuration of remote options in the logConfig()
function
const { logConfig, logger } = require('@vtfk/logger')
// logConfig() is optional
logConfig({
remote: {
onlyInProd: true,
host: 'papertrail.example.com/v1/log',
token: 'jvkuvuyoufyofo8ygo8f609fo7ouyvcio7=',
level: 'warn'
},
teams: {
url: 'https://<tenant>.webhook.office.com/blablabla',
level: 'error'
}
prefix: 'prefixedValue',
suffix: 'suffixedValue'
})
// this will NOT log to remote since this level is "info" and lowest remote level is set to "warn"
logger('info', ['test', 'message'])
// this will log to remote since this level is "error" and lowest remote level is set to "warn"
const error = Error('Error in process')
logger('error', ['Error in app', error])
// OUTPUT
// NAME-OF-APP and VER-OF-APP is the value of "name" and "version" in your package.json
[ 2019.05.19 15:13:35 ] < INFO > {NAME-OF-APP} - {VER-OF-APP}: prefixedValue - test - message - suffixedValue
[ 2019.05.19 15:13:35 ] < ERROR > {NAME-OF-APP} - {VER-OF-APP}: prefixedValue - Error in app - Error: Error in process - suffixedValue
Configuration of remote options in the logConfig()
function
const { logConfig, logger } = require('@vtfk/logger')
// logConfig() is optional
logConfig({
remote: {
disabled: true,
onlyInProd: true,
host: 'papertrail.example.com/v1/log',
token: 'jvkuvuyoufyofo8ygo8f609fo7ouyvcio7='
},
teams: {
disabled: true,
url: 'https://<tenant>.webhook.office.com/blablabla'
}
prefix: 'prefixedValue',
suffix: 'suffixedValue'
})
logger('info', ['test', 'message'])
const error = Error('Error in process')
logger('error', ['Error in app', error])
// OUTPUT
// NAME-OF-APP and VER-OF-APP is the value of "name" and "version" in your package.json
[ 2019.05.19 15:13:35 ] < INFO > {NAME-OF-APP} - {VER-OF-APP}: prefixedValue - test - message - suffixedValue
[ 2019.05.19 15:13:35 ] < ERROR > {NAME-OF-APP} - {VER-OF-APP}: prefixedValue - Error in app - Error: Error in process - suffixedValue
Pass the context
object from Azure Function to add a invocationId and use context.log[level](message)
.
Note: If the
context
object contains all log functions (context.log[levels]
) then it will log using these instead ofoptions.localLogger
const { logConfig, logger } = require('@vtfk/logger')
module.exports = async function (context, req) {
logConfig({
azure: { context }, // Pass in the context. (Shorthand for 'azure: { context: context }' )
prefix: 'kittens'
})
logger('error', ['are too cute!'])
logger('warn', ['can scratch'])
logConfig({ azure: { excludeInvocationId: true } }) // Exclude the invocationId from now on
logger('info', ['are cats'])
context.res.body = '200 OK'
}
// OUTPUT
// NAME-OF-APP and VER-OF-APP is the value of "name" and "version" in your package.json
[2020-11-19T11:47:43.735Z] {NAME-OF-APP} - {VER-OF-APP}: 786df5ec-e19b-4f94-a65f-b86eed8df405 - kittens - are too cute!
[2020-11-19T11:47:43.737Z] {NAME-OF-APP} - {VER-OF-APP}: 786df5ec-e19b-4f94-a65f-b86eed8df405 - kittens - can scratch
[2020-11-19T11:47:43.737Z] {NAME-OF-APP} - {VER-OF-APP}: kittens - are cats // invocationId is now excluded
Remote logging is only enabled in a production enviroment (NODE_ENV === 'production'
), unless options.remote.onlyInProd === false
.