@ts-koa/koa-morgan

HTTP request logger middleware for Koa.js.

A TypeScript version for Koa.js, stripped down from: https://github.com/expressjs/morgan

Installation

This is a Node.js module available through the npm registry. Installation is done using the npm install command:

$ npm i @ts-koa/koa-morgan

Basic Usage:

import { morgan } from "@ts-koa/koa-morgan"

const app = new Koa()
app.use(morgan())

Notes

Recommended that you .use() this middleware near the top to "wrap" all subsequent middleware.

API

morgan(format, options)

Create a new morgan logger middleware function using the given format and options. The format argument may be a string of a predefined name (see below for the names) or a string of a format string.

Using a predefined format string:

morgan("dev")

Using format string of predefined tokens:

morgan(":method :url :status :res[content-length] - :response-time ms")

Options

Morgan accepts these properties in the options object.

logger

Output logger for writing log lines, defaults to console.log.
Argument type: MorganLogger

type MorganLogger = (message: any) => void

colored

A boolean that indicates whether to print out status code with colors or not. Defaults to false.
If set to true, The :status token will be colored green for success codes, red for server error codes, yellow for client error codes, cyan for redirection codes, and uncolored for information codes.

skip

Function to determine if logging is skipped, defaults to false. This function will be called as skip(req, res).

// EXAMPLE: only log error responses
morgan("combined", {
  skip: (ctx: Context) => {
    return ctx.status < 400
  },
})

Predefined Formats

There are various pre-defined formats provided:

combined

Standard Apache combined log output.

:remote-addr - :remote-user [:date[clf]] ":method :url HTTP/:http-version" :status :res[content-length] ":referrer" ":user-agent"

common

Standard Apache common log output.

:remote-addr - :remote-user [:date[clf]] ":method :url HTTP/:http-version" :status :res[content-length]

dev

Concise output colored by response status for development use.

:method :url :status :response-time ms - :res[content-length]

short

Shorter than default, also including response time.

:remote-addr :remote-user :method :url HTTP/:http-version :status :res[content-length] - :response-time ms

tiny

The minimal output.

:method :url :status :res[content-length] - :response-time ms

Tokens

:date[format]

The current date and time in UTC. The available formats are:

• clf for the common log format ("10/Oct/2000:13:55:36 +0000")
• iso for the common ISO 8601 date time format (2000-10-10T13:55:36.000Z)
• web for the common RFC 1123 date time format (Tue, 10 Oct 2000 13:55:36 GMT)

If no format is given, then the default is web.

:http-version

The HTTP version of the request.

:method

The HTTP method of the request.

:referrer

The Referrer header of the request. This will use the standard mis-spelled Referer header if exists, otherwise Referrer.

:remote-addr

The remote address of the request. This will use ctx.request.ip, otherwise the standard req.socket.remoteAddress value.

:remote-user

The user authenticated as part of Basic auth for the request.

:req[header]

The given header of the request. If the header is not present, the value will be displayed as "-" in the log.

:res[header]

The given header of the response. If the header is not present, the value will be displayed as "-" in the log.

:response-time

The time between the request coming into morgan and when the response headers are written, in milliseconds.

:status

The status code of the response.

:url

The URL of the request. Uses ctx.url.

:user-agent

The contents of the User-Agent header of the request.

Misc

Special thanks to the authors of Express.js/Morgan, as I have learned much from this simple project.
I am glad that I started watching the whole series after it's completed. :)

License

MIT