BifroMQ's plugin mechanism allows users to integrate custom business logic with BifroMQ at runtime. Currently, BifroMQ defines 3 types of Plugin interfaces, i.e. Auth Provider, Event Collector and Setting Provider. This repository implements auth provider.
The plugin assumes a use case where users can log in to an app through social media accounts such as GMail and WeChat, and control smart appliances remotely or receive notifications via the app. The scenario can be depicted as the following picture.
For the scenario mentioned above, both application users and appliances essentially connect to BifroMQ with distinct roles. Meanwhile, it can be much easier and more convenient for users to connect to BifroMQ with social accounts.
In addition to do the authentication, the auth plugin should check the action permission for coming publishing and subscription messages, i.e. authorization.
In the project directory, run the maven command:
mvn clean packageThere will be 2 outputs, i.e. auth-service-${PROJECT_VERSION}.tar.gz and auth-plugin-${PROJECT_VERSION}.jar.
The first one is used for customized auth service including authentication and authorization.
The second one should be put in BifroMQ plugin directory. Also, auth provider fully qualified name(FQN)
in BifroMQ configuration file should be included, which is demonstrated in
Plugin Practice and Notice in BifroMQ.
Extract the auth-service-${PROJECT_VERSION}.tar.gz, cd auth-service-${PROJECT_VERSION}
and ./bin/auth-service.sh start to start the auth-service.
Based on the previous discussion, the login process should be done based on the client identity. In the project, WeChat and Auth0 authentication is supported. Additionally, it can be extended to support more social media accounts. In general, the interactions with third-party services are similar.
The process for each identity authentication is demonstrated as follows:
Device
As shown in the above figure, the customized auth service has to query users' credentials from database. In the project,
the interface IAuthStorage is provided and MySqlAuthStorage is implemented based on the interface. One can also
extend the implementation, e.g. redis and mongo.
Noticing, there is a implicit prerequisite, i.e. the credentials have been store in the database in advance. It can be done by other services, which is omitted here.
Auth0
For authorization, the project adopts Access Control List (ACL). Each action, such as publishing and subscription, has its own permission rule. For simplicity, the permissions are based on each user rather than the client. Therefore, clients under the same user share the same behavior.
In the project, MySql is adopted for storing users' permissions in the following table:
| username | pubAcl | subAcl |
|---|---|---|
| "dev" | "a/b, a/+/c" | "a/#" |
| "test" | "+/b" | "#" |
In pubAcl and subAcl, the rules are comma seperated. Also, being similar to authentication, the rules should be
stored in advance by other services.
It's important to note that subscription and unsubscription are considered the same action in the auth plugin.
Since BifroMQ's plugin interface implementations are called during the connection and message distribution processes, it's crucial to ensure they are lightweight to avoid bottlenecks. Therefore, in the auth plugin, all the work is done asynchronously.
Furthermore, based on experience, users' credentials and action permissions do not change frequently. Even during the user's lifecycle, the information will remain unchanged. As a result, caching is introduced in the auth service to reduce I/O costs.