Middlewares

1: Channeldata validator middleware
2: User middleware

Aura Groot middlewares

Description of middlewares included in aura-groot

Introduction

The current document describes the different middlewares that are part of aura-groot

init-middleware

This middleware is in charge of setting the initial context values (userData accessor, conversationData accessor, correlator) for the rest of the middlewares/handlers.

user-middleware

In this middleware, the user is checked and stored in context for the following middlewares/handlers.

Find detailed information in user-middleware documentation.

channeldata-validator-middleware

This middleware validates input channelData activities and throws an error if something is wrong.

Find more information in channeldata-validator-middleware documentation.

1 - Channeldata validator middleware

Channeldata validator middleware

Description of channeldata-validator-middleware, in charge of the validation of the request channelData for normalized versions

Introduction

The source code of this middleware is included in this Github repository.

This middleware will check if the channelData of the incoming request is valid or not. This validation is made:

If the environment variable AURA_CHANNELDATA_VALIDATION is set to true.
If the incoming channelData version is greater or equal than AURA_CHANNELDATA_VALIDATION_MIN_VERSION.
If a validator for this version exists. Validators are loaded using schemas stored in aura-models package.

If the validation is ok or is not executed because one or more of the previous conditions are not satisfied, aura-groot continues the normal flow, executing the rest of middlewares.

If the validation fails, the error message core:core.model-validation.request.error will be returned to the user and no more middlewares will be executed.

2 - User middleware

User middleware

Description of user-middleware in charge of the validation of the user’s data

Introduction

user-middleware is the middleware in charge of validating auraId and channel.

This is needed in aura-groot because routing is currently done by channel, so if the request does not include channelId (mandatory only in channelData v3), the user must be checked in aura-authentication-api to obtain the channel of this user.

This middleware throws an error if there is not activity.from.id or if some error is returned by aura-authentication-api (except 404, because anonymous users should continue the flow).

This middleware also handles a basic user’s cache to avoid unnecessary calls to aura-authentication-api with every user’s request. This cache is implemented using bot UserState.