https://github.com/salimkayabasi/log4json
JSON layout for log4js
https://github.com/salimkayabasi/log4json
json kibana log4js logging
Last synced: 2 months ago
JSON representation
JSON layout for log4js
- Host: GitHub
- URL: https://github.com/salimkayabasi/log4json
- Owner: salimkayabasi
- Created: 2018-03-21T13:47:10.000Z (over 8 years ago)
- Default Branch: main
- Last Pushed: 2022-10-01T02:52:59.000Z (over 3 years ago)
- Last Synced: 2025-10-25T04:43:18.043Z (8 months ago)
- Topics: json, kibana, log4js, logging
- Language: JavaScript
- Homepage:
- Size: 654 KB
- Stars: 0
- Watchers: 0
- Forks: 1
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
[](https://www.npmjs.com/package/log4json)
[](https://david-dm.org/salimkayabasi/log4json)
[](https://david-dm.org/salimkayabasi/log4json#info=devDependencies)
[](https://david-dm.org/salimkayabasi/log4json#info=peerDependencies)
# Log4JSON
JSON layout for [log4js](https://www.npmjs.com/package/log4js). Zero dependency and super slim.
## Options
### `separator` (default: `' '`)
Once you have multiple messages as in string format, `logger` will concat all of them and needs a separator.
This value will be used while concatenating the strings.
### `space` (default: `null`)
This parameter will help you to format your output. By default, it will log whole output in one line, otherwise multilines.
Please check the `space` argument on [JSON.stringify()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify) documentation.
### `omitDefaultCategory` (default: `true`)
In order to reduce the redunnant log size, default category name will be omitted. In case of you want to have category name as always.
You can force logger to include category name even when it is deafult
### `props`
Any of the property names can be overridden. You can override all field names on output.
Default propery names are;
```json
{
"ts": "ts",
"level": "level",
"category": "category",
"stack": "stack",
"message": "message",
"callStack": "callStack"
}
```
## Full Example
https://runkit.com/salimkayabasi/log4json
```javascript
const log4js = require('log4js');
const log4json = require('log4json');
addLayout('log4json', log4json);
configure({
appenders: {
log4json: {
type: 'console',
layout: {
type: 'log4json',
separator: ' | ',
space: 2,
omitDefaultCategory: false,
props: {
ts: '@timestamp',
level: 'lvl',
category: 'cat', // default category will be omitted unless "omitDefaultCategory" is false
stack: 'error', // only available when an error object is being logged
message: 'context',
callStack: 'stack', // only available when "enableCallStack" is true
}
}
}
},
categories: {
default: {
appenders: ['log4json'],
level: 'all',
enableCallStack: true
}
}
});
const logger = getLogger('fancy-category');
logger.debug('string logs', 'another string log', {customProp: ['also listed', true]}, 'yet another string');
```
#### output
```json
{
"customProp": [
"also listed",
true
],
"context": "string logs | another string log | yet another string",
"@timestamp": "2021-05-10T15:25:49.130Z",
"lvl": "DEBUG",
"cat": "fancy-category",
"stack": "src/log4json.js:37:8"
}
```