Osprey

Generate API middleware from a RAML definition, which can be used locally or globally for validating API requests and responses.

Features

• Automatic Request Validations
  • Bodies
  • Form data
  • Url Encoded bodies
  • JSON schemas
  • XML schemas
  • Headers
  • Query parameters
  • RAML 1.0 types
• Automatic Request Parameters
  • Default Headers
  • Default Parameters
• RAML Router
  • Uses osprey-router for RAML paths
• Integrates with Express-format middleware servers
  • Simple

    req

    /

    res

    /

    next

    middleware format that works with Connect, Express and even

    http

• API documentation Currently disabled
  • Optionally mount API documentation generated from your RAML definition
• Built-in Error Handling Middleware
  • I18n support
  • Map validation paths to readable strings (with i18n support)
• Built-in Response Handling Coming soon
  • Validate response bodies against status code definition
  • Automatically fill default response headers
• Authentication
  • OAuth 1.0 Coming Soon
  • OAuth 2.0
  • Basic Authentication
  • Digest Authentication
  • Custom Security Schemes
• RAML Mock Service

Osprey is built to enforce a documentation-first approach to APIs. It achieves this by:

Server

1. 404

   ing on undocumented resources
2. Rejecting invalid requests bodies, headers and query parameters
3. Populating default headers and query parameters
4. Filtering undocumented headers and query parameters
5. Validating API responses Coming soon
6. Fill default response headers Coming soon

Security

1. Setting up authentication endpoints and methods for you
2. Authenticating endpoints as defined in RAML

Installation

Global

npm install osprey -g

Osprey can be used as a validation proxy with any other API server. Just install the module globally and use the CLI to set up the application endpoint(s) to proxy, as well as the RAML definition to use. Invalid API requests will be blocked before they reach your application server.

# Proxy to a running application (with optional documentation)
osprey -f api.raml -p 3000 -a localhost:8080

Options

• -a

  Application endpoint address (can be fully qualified URLs) and specify multiple, comma-separated addresses

• -f

  Path to the root RAML definition (E.g.

  /path/to/api.raml

  )

• -p

  Port number to bind the proxy locally

Locally

npm install osprey --save

Usage

Osprey is normally used as a local node module and is compatible with any library supporting HTTP middleware, including Express and Connect. Just require the module locally and generate the middleware from a RAML definition file.

const osprey = require('osprey')
const express = require('express')
const join = require('path').join
const app = express()

const path = join(__dirname, 'assets', 'api.raml')
// Be careful, this uses all middleware functions by default. You might just
// want to use each one separately instead - osprey.server, etc.
osprey.loadFile(path)
  .then(function (middleware) {
    app.use(middleware)
app.use(function (err, req, res, next) {
  // Handle errors.
})

app.listen(3000)
  })
   .catch(function(e) { console.error("Error: %s", e.message); });

Please note: The middleware function does not use the RAML

baseUri

app.use('/v1', middleware)

Server (Resource Handling)

const wap = require('webapi-parser').WebApiParser

// webapi-parser.WebApiDocument
const model = wap.raml10.parse('/some/api.raml')
const handler = osprey.server(model, options)
console.log(handler) //=> function (req, res, next) {}
console.log(handler.ramlUriParameters) //=> {} // A merged object of used URI parameters.

Undefined API requests will always be rejected with a 404.

Options

These are also passed along to osprey-method-handler).

• cors Enable CORS by setting to

  true

  or an object from cors (default:

  false

  )
• compression Enable response compression using compression (default:

  false

  )
• notFoundHandler Use a

  404

  error in middleware to skip over invalid/undefined routes from RAML (default:

  true

  )

From Osprey Method Handler:

• discardUnknownBodies Discard undefined request bodies (default:

  true

  )
• discardUnknownQueryParameters Discard undefined query parameters (default:

  true

  )
• discardUnknownHeaders Discard undefined header parameters (always includes known headers) (default:

  true

  )
• parseBodiesOnWildcard Toggle parsing bodies on wildcard body support (default:

  false

  )
• reviver The reviver passed to JSON.parse for JSON endpoints
• limit The maximum bytes for XML, JSON and URL-encoded endpoints (default:

  '100kb'

  )
• parameterLimit The maximum number of URL-encoded parameters (default:

  1000

  )
• busboyLimits The limits for Busboy multipart form parsing

If you disable the default "not found" handler, it should be mounted later using

osprey.server.notFoundHandler

app.use(osprey.server.notFoundHandler)

Invalid Headers and Query Parameters

Invalid headers and query parameters are removed from the request. To read them they need to be documented in the RAML definition.

Request Bodies

Request bodies are parsed and validated for you, when you define the schema.

For

application/json

application/x-www-form-urlencoded

req.body

text/xml

req.body

req.xml

multipart/form-data

app.post('/users/{userId}', function (req, res, next) {
  req.form.on('field', function (name, value) {
    console.log(name + '=' + value)
  })

  req.form.on('file', function (name, stream, filename) {
    stream.pipe(fs.createWriteStream(join(os.tmpDir(), filename)))
  })
  req.form.on('error', next)
  req.pipe(req.form)
})

Headers, Parameters and Query Parameters

All parameters are automatically validated and parsed to the correct types according to the RAML document using webapi-parser and raml-sanitize. URL parameter validation comes with Osprey Router, available using

osprey.Router

// Similar to `express.Router`, but uses RAML paths.
const Router = require('osprey').Router
const utils = require('./utils')

// Array<webapi-parser.parameter>
const parameters = utils.getUriParameters()
const app = new Router()
app.use(...)
app.get('/{slug}', parameters, function (req, res) {
  res.send('success')
})
module.exports = app
</webapi-parser.parameter>

You can initialize a

Router

ramlUriParameters

server

const handler = osprey.server(model)
const router = osprey.Router({ ramlUriParameters: handler.ramlUriParameters })

// Uses an existing userId URI parameter, if it exists.
router.get('/{userId}', function (req, res, next) {})

Handling Errors

Osprey returns a middleware router instance, so you can mount this within any compatible application and handle errors with the framework. For example, using HTTP with finalhandler (the same module Express uses):

const http = require('http')
const osprey = require('osprey')
const finalhandler = require('finalhandler')
const join = require('path').join

osprey.loadFile(join(__dirname, 'api.raml'))
  .then(function (middleware) {
    http.createServer(function (req, res) {
      middleware(req, res, finalhandler(req, res))
    }).listen(process.env.PORT || 3000)
  })
   .catch(function(e) { console.error("Error: %s", e.message); });

Error Types

• error.ramlAuthorization = true

  An unauthorized error containing an array of errors that occured is set on

  error.authorizationErrors

• error.ramlValidation = true

  A request failed validation and an array of validation data is set on

  error.requestErrors

  (beware, different types contain different information)

• error.ramlNotFound = true

  A request 404'd because it was not specified in the RAML definition for the API

Add JSON Schemas

JSON schemas can be added to the application for when external JSON references are needed. From osprey-method-handler.

osprey.addJsonSchema(schema, key)

Error Handler

Osprey comes with support for a built-in error handler middleware that formats request errors for APIs. It comes with built-in i18n with some languages already included for certain formats (help us add more!). The default fallback language is

en

const osprey = require('osprey')
const app = require('express')()

// It's best to use the default responder, but it's overridable if you need it.
app.use(osprey.errorHandler(function (req, res, errors, stack) { /* Override */ }, 'en'))

You can override the i18n messages or provide your own by passing a nested object that conforms to the following interface:

interface CustomMessages {
  [type: string]: {
    [keyword: string]: {
      [language: string]: (error: RequestError) => string
    }
  }
}

The request error interface is as follows:

interface RequestError {
  type: 'json' | 'form' | 'headers' | 'query' | 'xml' | string
  message: string /* Merged with i18n when available */
  keyword: string /* Keyword that failed validation */
  id?: string /* A unique identifier for the instance of this error */
  dataPath?: string /* Natural path to the error message (E.g. JSON Pointers when using JSON) */
  data?: any /* The data that failed validation */
  schema?: any /* The schema value that failed validation */
  detail?: string /* Additional details about this specific error instance */
  meta?: { [name: string]: string } /* Meta data from the error (XML validation provides a code, column, etc.) */
}

Want to format your own request errors? If you emit an error with a

.status

400

499

requestErrors

status

Security

// model is an instance of webapi-parser WebApiDocument
osprey.security(model, options)

Osprey accepts an options object that maps object keys to the security scheme name in the RAML definition.

OAuth 2.0

Provided by OAuth2orize and Passport.

securitySchemes:
  - oauth_2_0:
      type: OAuth 2.0
      settings:
        authorizationUri: https://example.com/oauth/authorize
        accessTokenUri: https://example.com/oauth/token
        authorizationGrants: [ code, token, owner, credentials ]
        scopes:
          - profile
          - history
          - history_lite
          - request
          - request_receipt

OAuth 2.0 can be fairly tricky to enforce on your own. With Osprey, any endpoint with

securedBy

Required Options (by grant type)

• All

  • authenticateClient

  • exchange.refresh

    When refresh tokens are used

• Code and Token

  • serializeClient

  • deserializeClient

  • authorizeClient

  • sessionKeys

  • ensureLoggedIn

    Has access to

    req.session

  • serveAuthorizationPage

    Has access to

    req.session

• Code

  • grant.code

  • exchange.code

• Token

  • grant.token

• Credentials

  • exchange.credentials

• Owner

  • exchange.owner

The authorization page must submit a POST request to the same URL with the

transaction_id

scope

req.oauth2

cancel=true

immediateAuthorization

// model is an instance of webapi-parser WebApiDocument
osprey.security(model, {
  oauth_2_0: {
    // Optionally override `accessTokenUri` and `authorizationUri` when needed.
    // They need to match the suffix defined in the security scheme.
    accessTokenUri: '/oauth/token',
    authorizationUri: '/oauth/authorize',
    // Serialize the client object into the session.
    serializeClient: function (application, done) {
      return done(null, application.id)
    },
    // Deserialize client objects out of the session.
    deserializeClient: function (id, done) {
      Client.findById(id, function (err, client) {
        done(err, client)
      })
    },
    authorizeClient: function (clientId, redirectUri, scope, type, done) {
      Clients.findOne(clientId, function (err, client) {
        if (err) { return done(err) }
        if (!client) { return done(null, false) }
        if (!client.redirectUri != redirectUri) { return done(null, false) }
        return done(null, client, client.redirectUri)
      })
    },
    authenticateClient: function (clientId, clientSecret, done) {
      Clients.findOne({ clientId: clientId }, function (err, client) {
        if (err) { return done(err) }
        if (!client) { return done(null, false) }
        if (client.clientSecret != clientSecret) { return done(null, false) }
        return done(null, client)
      })
    },
    findUserByToken: function (token, done) {
      User.findOne({ token: token }, function (err, user) {
        if (err) { return done(err) }
        if (!user) { return done(null, false) }
        return done(null, user, { scope: 'all' })
      })
    },
    // An array of unique session keys to sign and verify cookies.
    sessionKeys: ['a', 'b', 'c', ...],
    ensureLoggedIn: function (req, res, next) {
      // For example: https://github.com/jaredhanson/connect-ensure-login
    },
    immediateAuthorization: function (client, user, scope, done) {
      return done(null, false)
    },
    serveAuthorizationPage: function (req, res) {
      res.render('dialog', {
        transactionId: req.oauth2.transactionID,
        user: req.user,
        client: req.oauth2.client
      })
    },
    grant: {
      code: function (client, redirectUri, user, ares, done) {
        AuthorizationCode.create(client.id, redirectUri, user.id, ares.scope, function (err, code) {
          if (err) { return done(err) }
          done(null, code)
        })
      },
      token: function (client, user, ares, done) {
        AccessToken.create(client, user, ares.scope, function (err, accessToken) {
          if (err) { return done(err) }
          done(null, accessToken /*, params */)
        })
      }
    },
    exchange: {
      code: function (client, code, redirectUri, done) {
        AccessToken.create(client, code, redirectUri, function (err, accessToken) {
          if (err) { return done(err) }
          done(null, accessToken /*, refreshToken, params */)
        })
      },
      credentials: function (client, scope, done) {
        AccessToken.create(client, scope, function (err, accessToken) {
          if (err) { return done(err) }
          done(null, accessToken /*, refreshToken, params */)
        })
      },
      owner: function (client, username, password, scope, done) {
        AccessToken.create(client, username, password, scope, function (err, accessToken) {
          if (err) { return done(err) }
          done(null, accessToken /*, refreshToken, params */)
        })
      },
      refresh: function (client, refreshToken, scope, done) {
        AccessToken.create(client, refreshToken, scope, function (err, accessToken) {
          if (err) { return done(err) }
          done(null, accessToken /*, refreshToken, params */)
        })
      }
    }
  }
})

Osprey will automatically block requests with invalid scopes, when defined in RAML using the inline option syntax.

/example:
  securedBy: [oauth_2_0: { scopes: [ ADMINISTRATOR ] } ]

To implement scope validation in your own application, without RAML, use

osprey.security.scope('example')

app.get('/foo/bar', osprey.security.scope('example'), function (req, res) {
  res.send('hello, world')
})

Please note: OAuth 2.0 does not (currently) take into account security scheme

describedBy

OAuth 1.0

Coming soon...

Basic Authentication

Provided by Passport-HTTP.

securitySchemes:
  - basic_auth:
      type: Basic Authentication

// model is an instance of webapi-parser WebApiDocument
osprey.security(model, {
  basic_auth: {
    realm: 'Users', // Optional.
    passReqToCallback: false, // Optional. Default value: false. If true "req" is added as the first callback argument.
    validateUser: function (username, password, done) {
      User.findOne({ username: username }, function (err, user) {
        if (err) { return done(err) }
        if (!user) { return done(null, false) }
        if (!user.verifyPassword(password)) { return done(null, false) }
        return done(null, user)
      })
    }
  }
})

Digest Authentication

Provided by Passport-HTTP.

securitySchemes:
  - digest_auth:
      type: Digest Authentication

// model is an instance of webapi-parser WebApiDocument
osprey.security(model, {
  digest_auth: {
    realm: 'Users', // Optional.
    domain: 'example.com', // Optional.
    findUserByUsername: function (username, done) {
      User.findOne({ username: username }, function (err, user) {
        if (err) { return done(err) }
        if (!user) { return done(null, false) }
        return done(null, user, user.password)
      })
    }
  }
})

Custom Security Schemes

To register a custom security scheme, you can pass in your own function.

securitySchemes:
  - custom_auth:
      type: x-custom

The function must return an object with a handler and, optionally, a router. The router will be mounted immediately and the handler will be called on every secured route with the secured by options and the RAML path.

// model is an instance of webapi-parser WebApiDocument
osprey.security(model, {
  custom_auth: function (scheme, name) {
    return {
      handler: function (options, path) {
        return function (req, res, next) {
          return next()
        }
      },
      router: function (req, res, next) {
        return next()
      }
    }
  }
})

Proxy

osprey.proxy(middleware, addresses)

Pass in an Osprey middleware function with an array of addresses to proxy to and you have a fully-functioning validation and/or security proxy.

License

Apache 2.0