swagger.js

var config = require('./package.json')
var extend = require('xtend')

function lambdaUri (args) {
  var region = 'us-east-1'
  var accountId = args.accountId
  var functionName = args.functionName

  return 'arn:aws:apigateway:' + region + ':lambda:path/2015-03-31/functions/arn:aws:lambda:' + region + ':' + accountId + ':function:' + functionName + '/invocations'
}

function integration (config, functionName) {
  return {
    type: 'aws',
    uri: lambdaUri({ accountId: config.deploy.accountId, functionName: functionName }),
    credentials: 'arn:aws:iam::' + config.deploy.accountId + ':role/' + config.deploy.roleName,
    httpMethod: 'POST',
    responses: {
      '.*error.*': {
        statusCode: '400'
      },
      default: {
        statusCode: '200'
      }
    }
  }
}

function transformOperation (paths, transform) {
  paths = extend(paths)

  Object.keys(paths).map(function (path) {
    Object.keys(paths[path]).map(function (method) {
      var operation = paths[path][method]

      paths[path][method] = transform(operation)
    })
  })

  return paths
}

function operationIdToFunctionName (config, operationId) {
  return config.name + '-' + operationId.replace(/[^a-zA-Z0-9-_]/g, '-')
}

function convertPaths (paths) {
  return transformOperation(paths, function (operation) {
    operation['x-amazon-apigateway-auth'] = {
      type: 'none'
    }

    var functionName = operationIdToFunctionName(config, operation.operationId)
    operation['x-amazon-apigateway-integration'] = integration(config, functionName)

    return operation
  })
}

var swagger = {
  swagger: '2.0',
  info: {
    title: config.name,
    description: config.description || config.name,
    version: config.version
  },
  schemes: ['http', 'https'],
  paths: convertPaths(config.deploy.paths)
}

console.log(JSON.stringify(swagger, null, 2))