@kasa/koa-logging
A middleware that logs request and response in Koa
## Installation
```bash
# Using NPM
$ npm install --save @kasa/koa-logging
# Using Yarn
$ yarn add @kasa/koa-logging
```
### Dependencies
- [**Koa**](https://github.com/koajs/koa) 2.0+
- [**Node.js**](https://nodejs.org) 8.0.0+
## Usage
Use `koa-request-id` as a middleware for a [koa](https://github.com/koajs/koa) app. By default, it writes logs into `stdin` for HTTP requests, responses and errors. Every log include the request id, which logger will try to get from common places such as `ctx.reqId`, `ctx.state.reqId`, `ctx.req.id`.
In the following example, you can check the request and response logs from `stdin`:
```js
// app.js
const Koa = require('koa');
const requestId = require('@kasa/koa-request-id');
const logging = require('@kasa/koa-logging');
const pino = require('pino');
const app = new Koa();
app.use(requestId());
app.use(logging({ logger: pino() }));
app.use(async ctx => {
ctx.body = 'Hello, logging!';
});
app.listen(3000);
```
```bash
$ node app.js || pino-pretty -c -l -t
```
```bash
$ curl -X POST http://localhost:3000/users
```
```bash
INFO [2018-11-04 09:54:00.596 +0000] (app/15600 on my-macbook): POST /users (4f83e15b-c34c-4f8c-9f57-938e54e54ae3)
reqId: "4f83e15b-c34c-4f8c-9f57-938e54e54ae3"
req: {
"method": "POST",
"path": "/users",
"url": "/users",
"headers": {
"host": "localhost:3000",
"user-agent": "curl/7.54.0",
"accept": "*/*"
},
"protocol": "http",
"ip": "127.0.0.1",
"query": {}
}
event: "request"
```
## API
### Creating an middleware
You can create a new logging middleware by passing the existing pino logger and the relevant options to `logging`;
```node
const logger = pino();
const middleware = logging({
logger,
serializers: {},
overrideSerializers: true,
getReqId: (ctx) => ctx.reqId,
getRequestLogLevel: (ctx) => 'info',
getResponseLogLevel: (ctx) => ctx.state >= 500 ? 'error' : 'info',
getErrorLogLevel: (err) => 'error'
});
```
### Middleware Configuration
These are the available config options for the middleware. All is optional except `logger`.
```node
{
// Logger instance of pino
logger: pino(),
// Serializers to override defaults provided
serializers: {
req: (ctx) => ({
...
}),
user: (ctx) => ({
...
})
},
// Ovveride serializers if true (default: true)
overrideSerializers: true,
// Function to get the request id from `ctx`
getReqId: (ctx) => ctx.reqId,
// Function to decide log level of the request from `ctx`
getRequestLogLevel: (ctx) => 'info',
// Function to decide log level of the response from `ctx`
getResponseLogLevel: (ctx) => ctx.state >= 500 ? 'error' : 'info',
// Function to decide log level of the error from `err`
getErrorLogLevel: (err) => 'error'
}
```
## Contributing
#### Bug Reports & Feature Requests
Please use the [issue tracker](https://github.com/kasa-network/koa-logging/issues) to report any bugs or ask feature requests.
## License
Copyright © 2018, [Kasa](http://www.kasa.network).
