Add support for HTTP servers and clients

[fmvilas]

Reason/Context

Currently, Glee only supports WebSocket and MQTT protocols. That makes it unusable for someone wanting to use any other protocol, like HTTP.

Description

Glee should be able to create an HTTP server (API) or a client out of an AsyncAPI definition. We can probably use the same x-kind extension defined in #259, as a way to understand when we want a client and when we want a server.

One key part of this issue is to actually work on the HTTP binding. Especially, in this issue about adding support for multiple methods.

[AMorgaut]

To me there is a specific usage of HTTP that totally makes sense for AsyncAPI and which is not WebSocket

I'm thinking about EventSource aka "Server-Sent Events" which is typically event-based

The protocol definition can be seen there:
https://html.spec.whatwg.org/multipage/server-sent-events.html#server-sent-events

but it probably deserve a seperated feature request issue

[fmvilas]

That's a good point, @AMorgaut. I don't think it should be separated. We should aim for full HTTP support IMHO.

[Souvikns]

@fmvilas by client do you mean glee server will make a API call to the client server as per the bindings information and the data that is returned from operationId function?

[fmvilas]

Nope. I mean Glee should behave like a client not like a server. It should make calls to some APIs but it shouldn't be a server itself.

[Souvikns]

Nope. I mean Glee should behave like a client not like a server. It should make calls to some APIs but it shouldn't be a server itself.

🤔 Kinda confused, I should be able to create a http REST API with glee if I want right, so like I would make an API call to glee through http and get a response. Would you call it a server?

[fmvilas]

Yeah sorry, somehow I got confused by your question too. What I mean is that Glee should behave in two different ways, depending on how you configure your AsyncAPI document:

1. As a server: this would, for instance, leverage ExpressJS or something similar behind the scenes. This is for people who want to create a REST API.
2. As a client: this would let you make calls to other REST APIs. Say, for instance, every time you receive a message via MQTT you want to call a 3rd-party REST API. That should be possible too.

Note that a Glee application may be a mix of both, a client and a server. For instance, imagine we want to create a REST API, and every time the user does POST /users we want to call an external service, e.g., the Google Analytics API, another API in our system, etc.

Does that make sense?

[ritik307]

Hi, @fmvilas I would like to work on this issue. So can you kindly help me out in figuring out where to start? Like should I start making REST APIs or some other approach? 😊

[Souvikns]

Hey, @ritik307 I was working on this issue and made some progress as well #265, since we need to update the bindings I am focusing on that right now asyncapi/bindings#131. I would love to mentor you (if you want me as a mentor) if this idea gets issue gets selected.

[ayushpaharia]

Hello @Souvikns Can you give some context on this issue. I'm interested in working on this as a Mentorship project

[Souvikns]

So I will be mentoring this issue if it gets selected 😄 . To answer both @ayushpaharia and @ritik307 you should start getting familiar with glee and its codebase. I would suggest you fork and play around with glee. look into the examples folder to get a better understanding of how glee is working. Secondly, start reading the codebase and tweaking some code here and there to get a feel of things.

Also, check out #265, and even review it. You guys can also join the asyncapi/community#352 meeting for understanding how the HTTP binding will shape up. Lastly, feel free to ask any questions you have here or on slack.

[ritik307]

@Souvikns Will surely start exploring the glee. 😄

[ayushpaharia]

#265 - Looks interesting. I'll get started with playing around with glee. See you in asyncapi/community/#352 💯 @Souvikns

[Souvikns]

So this idea was selected for AsyncAPI Mentorship 2022 ->
asyncapi/community#376 (comment)

@ritik307 since you contributed to cli, modelina, website, and many more projects, I would like to select you as a mentee for this issue- would you like to become an AsyncAPI-sponsored mentee for this idea? 🙏🏼I would be your mentor for the coming months.

[ritik307]

@Souvikns I will be more than happy to be mentee for the mentioned issue 😁. Thank you so much for providing me the opportunity.🥳

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity 😴

It will be closed in 120 days if no further activity occurs. To unstale this issue, add a comment with a detailed explanation.

There can be many reasons why some specific issue has no activity. The most probable cause is lack of time, not lack of interest. AsyncAPI Initiative is a Linux Foundation project not owned by a single for-profit company. It is a community-driven initiative ruled under open governance model.

Let us figure out together how to push this issue forward. Connect with us through one of many communication channels we established here.

Thank you for your patience ❤️

[Souvikns]

@fmvilas can you please reopen this, as it is being currently worked on #320