express-ipfilter-req/README.md

A light-weight IP address based filtering system

# express-ipfilter: A light-weight IP address based filtering system

This package provides easy IP based access control. This can be achieved either by blacklisting certain IPs and whitelisting all others, or whitelisting certain IPs and blacklisting all others.

## Installation

Recommended installation is with npm. To add express-ipfilter to your project, do:

    npm install varmil/express-ipfilter

## Usage with Express

Blacklisting certain IP addresses, while allowing all other IPs:

```javascript
// Init dependencies
const express = require('express')
const ipfilter = require('express-ipfilter').IpFilter

// Blacklist the following IPs
const ips = ['127.0.0.1']

// Create the server
app.use(ipfilter(ips))
app.listen(3000)
```

Whitelisting certain IP addresses, while denying all other IPs:

```javascript
// Init dependencies
// Init dependencies
const express = require('express')
const ipfilter = require('express-ipfilter').IpFilter

// Whitelist the following IPs
const ips = ['127.0.0.1']

// Create the server
app.use(ipfilter(ips, { mode: 'allow' }))

module.exports = app
```

Using CIDR subnet masks for ranges:

```javascript
const ips = ['127.0.0.1/24']

// Create the server
app.use(ipfilter(ips, { mode: 'allow' }))

module.exports = app
```

Using IP ranges:

```javascript
const ips = [['127.0.0.1', '127.0.0.10']]

// Create the server
app.use(ipfilter(ips, { mode: 'allow' }))

module.exports = app
```

Using a function to get Ips:

```javascript
const ips = function(req) {
  return ['127.0.0.1']
}

// Create the server
app.use(ipfilter(ips, { mode: 'allow' }))

module.exports = app
```

## Error Handling

When an IP is denied, an IpDeniedError will be thrown by the middleware. If you do not handle the error, it will cause your app to crash due to an unhandled exception. Here is an example of how to handle the error, which can also be found in the example app:

```javascript
if (app.get('env') === 'development') {
  app.use((err, req, res, _next) => {
    console.log('Error handler', err)
    if (err instanceof IpDeniedError) {
      res.status(401)
    } else {
      res.status(err.status || 500)
    }

    res.render('error', {
      message: 'You shall not pass',
      error: err
    })
  })
}
```

You will need to require the `IpDeniedError` type in order to handle it.

## Options

| Property   | Description                                                                                                                                            | Type                                     | Default            |
| ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------- | ------------------ |
| mode       | whether to _deny_ or _allow_ to the IPs provided                                                                                                       | string                                   | deny               |
| log        | console log actions                                                                                                                                    | boolean                                  | true               |
| logLevel   | level of logging (_all_,_deny_,_allow_)                                                                                                                | string                                   | all                |
| excluding  | routes that should be excluded from ip filtering                                                                                                       | array                                    | []                 |
| detectIp   | define a custom function that takes an Express request object and returns an IP address to test against                                                | function                                 | built-in detection |
| trustProxy | This setting is implemented using the proxy-addr package. Check the [documentation](https://www.npmjs.com/package/proxy-addr) for the trust parameter. | boolean, array, string, number, function | false              |

> A note on detectIp

If you need to parse an IP address in a way that is not supported by default, you can write your own parser and pass that to `ipfilter`.

```javascript
const customDetection = req => {
  var ipAddress

  ipAddress = req.connection.remoteAddress.replace(/\//g, '.')

  return ipAddress
}

ipfilter(ids, { detectIp: customDetection })
```

## Contributing

See the `CONTRIBUTING.MD` document for more information on contributing.

### Running Tests

Run tests by using `npm test`

## Changelog

Moved to [GitHub Releases](https://github.com/casz/express-ipfilter/releases)

## Credits

BaM Interactive - [code.bamideas.com](http://code.bamideas.com)