MIM JSON proxy

A tool which can be used as ‘man in the middle’ proxy. It can be used to sit between two JSON webservices endpoints (e.g. Facebook/Twitter and your application) to intercept the webservices traffic between them and modify it.

Features

• Possibility to mock entire response and/or request
• Possibility to mock only part of response and/or request
• Possibility to mock response status code
• Simulate delays on service calls
• Easy way to change endpoints on the fly (i.e. developer / staging)
• JSON based configuration with JS defined rules for flexibility
• JSON based configuration is backed up by JSON schema

Getting started (API)

1. Install the proxy

   npm i mim-json-proxy

2. In the code

   const JsonProxy = require('mim-json-proxy');
   const proxy = new JsonProxy(options);
   proxy.start();

Getting started (command line)

1. Install the proxy

   npm install -g mim-json-proxy

2. Usage:

   mim-json-proxy {OPTIONS}

Examples

Examples can be found in the examples directory.

Options

Options are for API usage and the command line:

• port: port to open the server on (default 3005)
• configsDirectory: defines proxy configurations directory (default ./configs)
• defaultConfigName: defines default configuration name (default proxy-config.json)
• configUI.enabled: whether to enable the UI for easier proxy config adjustments (default true)
• configUI.endpoint: path for the config UI (default /config)
• bodyParserLimit: limit for express bodyParser (default 5mb)
• cors: cors configuration to pass to express (default {credentials: true})
• https: whether to start server using https or not (default false)
• certificates.key: HTTPS certificate key path (default ./certificates/server.key)
• certificates.cert: HTTPS certificate CRT path (default ./certificates/server.crt)

API

• start(options): starts the server with provided options
• addController(path, controller): possibility to define custom controller on the server (i.e. replacing /config)
• addDynamicRule(endpointName, func): add dynamic rule, the func takes following as argument: { requestBody, responseStatusCode, responseBody, isResponse, isRequest, reqURL, reqMethod }

Developer notes

• You can use npm start to run the proxy locally
• Proxy runs on port 3005 by default to relay the communication to webservice. The /config endpoint can be used to adjust the configuration in simple UI
• configs/proxy-config.json defines rules and endpoints
• proxy-config.schema.json defines how the above file should look like