Microsoft YARP

https://github.com/microsoft/reverse-proxy

by gokhan • 4 years ago

222 127 4 years ago

github.com

opan• 4 years ago

MIT license, nice.

older2• 4 years ago

I think it was initially Apache licinse but they re-licensed to MIT in order to submit it to CNCF.

riffic• 4 years ago

Yet Another Reverse Proxy.

Cute.

oneplane• 4 years ago

Sometimes it feels like Microsoft and/or C#-enjoyers just want to re-implement everything that already exists. While having many implementations to choose from if you need to select a solution to an outstanding problem is great, it makes me wonder why re-implementing something with no discernible benefit keeps eating time/resources all over the place.

In similar cases of implementing reverse proxies in C, C++, Rust, Go and Java, there were generally benefits in various shapes and sizes like different security models, performance vs. capability trade-offs and integrated vs. specialised solutions. In this case, it just seems to be a "we don't want the stuff we didn't build ourselves" which is a shame considering the benefits of pooling resources on existing implementations would have.

123pie123• 4 years ago

Sometimes it feels like Microsoft and/or C#-enjoyers just want to re-implement everything that already exists

It sometimes feels to me, like a huge percentage of developers reinvent the wheel

civilized• 4 years ago

There are thousands of Java accounting apps and thousands of shitty medical billing websites.

I think most devs are definitely reinventing the wheel for the ten thousandth time

amelius• 4 years ago

And how would we cope with this in, say, 100 years, when the list of required functionalities is much larger, and a new language comes along?

pjmlp4• 4 years ago

Ah, that is why cars still use chariot wheels.

bob10295• 4 years ago

re-implementing something with no discernible benefit keeps eating time/resources all over the place.
is a shame considering the benefits of pooling resources on existing implementations would have.

What exactly would you prefer these developers spend their time on instead of this work?

There are a lot of benefits to being able to integrate your own reverse proxy directly into your software stack. C# developers enjoy these as much as anyone else would.

jeeeb• 4 years ago

There are a lot of benefits to being able to integrate your own reverse proxy directly into your software stack. C# developers enjoy these as much as anyone else would.

I take this at face value but it would be nice to know what the benefits are vs nginx and other off the shelf solutions.

The readme explains the benefit for Microsoft but not how it stacks against off the self solutions.

qbasic_forever• 4 years ago

It's only in the last 5 years that .NET was open sourced and made available officially for Linux systems. Up until then most C# use was strictly on Windows, and OSS especially for Windows server side stuff (IIS, SQL server, etc.) was (and still is) pretty rare. I've seen windows server places (Microsoft) implement everything from redis, memcached, queue systems, prometheus, lucene, DNS servers, to reverse proxies, etc. entirely from scratch out of necessity. Years and years of man hours going into building and supporting something that would be a simple debian package install on Linux.

I have no insight into it but my gut tells me windows server exclusive shops are probably dwindling and have long ago realized they needed to start moving to Linux, especially now that .NET is officially supported there. I think the days of reinventing everything in C#/.NET/windows are coming to an end fast.

oaiey6• 4 years ago

And that is not a gut prediction but history. 15 years ago the default was Windows, .NET and SQL Server. 5 years ago it is Linux in the cloud, .NET and PostgreSQL.

rswail• 4 years ago

C#/.NET/CLR are competing against Java/JRE/JVM.

So reinventing "everything" in a Windows Server environment is slowly coming to an end, with Windows server becoming a hypervisor for VMs/containers and a runtime for .NET/CLR.

The economics of getting all of the FOSS infrastructure tooling in a "Windows native" form is being beaten by just running them in containers/VMs on whatever hypervisor is available.

In the same way, Linux is becoming a hypervisor for containers and the various container runtimes.

cakoose2• 4 years ago

To clarify, are you saying that:

1. There are already good reverse proxy libraries in C#?

2. There are already good reverse proxy libraries in other languages?

3. There are already good reverse proxy applications?

If it's #1, then yeah, it would be nice if the ReadMe explained why YARP is different. To be fair, they're at least consolidating a bunch of efforts within Microsoft:

We found a bunch of internal teams at Microsoft who were either building a reverse proxy for their service or had been asking about APIs and tech for building one, so we decided to get them all together to work on a common solution, this project.

If it's #2, then what do C# developers do? Having to build your proxy in another language isn't a deal-breaker, but there are advantages to keeping your project/team/company on a single language.

(And Microsoft does contribute to Envoy [1][2].)

If it's #3, that only works up to a point. My old team used Nginx, which was perfect in the beginning. But over time we needed to customize things in ways that were difficult to do within Nginx's architecture (either in Lua or in C), leading to hackier and hackier solutions. Using a proxy library to build exactly what you need can make things much simpler.

[1] https://blog.envoyproxy.io/general-availability-of-envoy-on-...

[2] https://techcrunch.com/2020/08/05/microsoft-launches-open-se...

bob10295• 4 years ago

But over time we needed to customize things in ways that were difficult to do within Nginx's architecture (either in Lua or in C), leading to hackier and hackier solutions. Using a proxy library to build exactly what you need can make things much simpler.

This is the central argument for me regarding why we don't "just use nginx". We actually do use it for some corporate websites, but not for our main product.

There is a ton of power hiding here... With a well-supported first-party RP framework, how long would it take for a determined developer to replicate the most important bits of the nginx feature set? Imagine being able to throw a blazor dashboard on top of this stuff. Wiring up real-time events/metrics would be super trivial if you are even remotely interested in learning how the DI system operates. Mix in a little bit of SQLite and you could have something I may argue provides a better UX than what nginx offers today.

kristaps2• 4 years ago

Can you share more specifics on what you needed to customize that went beyond nginx's capabilities?

zamalek• 4 years ago

But over time we needed to customize things in ways that were difficult to do within Nginx's architecture (either in Lua or in C),

Yup. Eventually a configuration language becomes a shitty programming language, so why don't we just use a programming language?

assttoasstmgr2• 4 years ago

Would your reaction have been different if, instead of Microsoft, this article was submitted by some random person entitled "Show HN: I built a reverse proxy in C#"?

By your logic, the world should be operating on a single OS, with a single web browser, paired with a single web server, because why re-implement something that already exists?

pydry2• 4 years ago

Pretty much every "I built a thing" post is met with the same response. MS isnt special.

I think pretty much every open source project that wants to be taken seriously needs to compare itself with its competitors.

AlphaSite• 4 years ago

It competes with this: https://spring.io/projects/spring-cloud-gateway AFAICT.

mrkurt2• 4 years ago

There aren't a lot of good proxy development frameworks. There are decent lower level libraries, and proxy servers with limited scriptability.

I've spent the last 4 years at Fly.io wishing for a nice, full featured, proxy framework. This looks pretty darn good to me.

melony• 4 years ago

The Go standard library?

sopium• 4 years ago

I find hyper quite nice to work with to build reverse proxies, mostly thanks to the HTTP client and server having common types for request, response, headers and body streams etc. I agree that it is only a decent lower level library rather than a full featured proxy framework though.

js4ever• 4 years ago

A Ruby on rails shop like fly.io would use .net?

codeulike• 4 years ago

Seems like the fact that its built in C# isn't really the main point. The main point it that it runs on asp.net infrastructure

bob10295• 4 years ago

I'm glad to see Microsoft supporting more low-level magic like this. I've written my own version of ReverseProxyMiddleware more times than I can recall... The most painful parts were always around translating between HttpClient and HttpContext. Looks like Microsoft abstracted this exact concern away under the IHttpForwarder and ForwarderHttpClientContext types.

Looking at the docs around this, I'd probably start w/ Direct Forwarding so I have more control over how things route:

https://microsoft.github.io/reverse-proxy/articles/direct-fo...

kwertyoowiyop• 4 years ago

They should’ve called it SNAP: Somebody Needs A Promotion

murrayb• 4 years ago

It's a reverse proxy so it's "pray", not exactly confidence inspiring! :-)

coredog64• 4 years ago

What are the odds that there's an AWS employee that will backronym this as part of their L7 promo doc for 2023?

davidfowl6• 4 years ago

This is a good one. Will remember it for the next project

rafale3• 4 years ago

How does this compare to nginx? Does it support websockets? I have an asp.net core websocket based app that need to support hundred of thousands concurrent websockets connection. I ll be taking a look at this because I don't wanna expose Kestrel directly to the internet.

oleksandr_kot• 4 years ago

Used it several weeks ago at work in an app which actively uses WebSockets. It just works.

politelemon• 4 years ago

The main difference I see is that YARP is added right into the dotnet project itself. See the getting started :

https://microsoft.github.io/reverse-proxy/articles/getting-s...

From my understanding Kestrel passes request to this.

The proxy server is implemented a plugin component for ASP.NET Core applications. ASP.NET Core servers like Kestrel provide the front end for the proxy by listening for http requests and then passing them to the proxy for paths that the proxy has registered.

rafale3• 4 years ago

I see. So it can operate in-process? Could in theory be much faster than nginx out-of-process model.

ComodoHacker• 4 years ago

So, basically vendor lock-in is the difference?

davidfowl6• 4 years ago

It supports WebSockets, HTTP/2 (including gRPC) and HTTP/3 (with .NET 6+).

Shadonototra2• 4 years ago

anything that requires a giant runtime to run is a big NO for me

that's why languages like GO makes more sense for that kind of use cases

microsoft not wanting to support CoreRT back in the days was their biggest mistake ever, shame on the people at microsoft who lobbied against it, shame!

dellamonica• 4 years ago

They are working on Native AOT for .net 7, which is based on CoreRT. See the issues tracked in the runtime repo.

I have been using it with reflection fully disabled in a console app and it produces a 5Mb native binary.

Shadonototra2• 4 years ago

ok that is VERY encouraging to hear!

thanks for letting me know about that

EDIT: found it: https://github.com/dotnet/runtime/issues/61231

ripley12• 4 years ago

I wouldn't say it's a giant runtime. A trimmed Hello World .NET app is ~11MB these days - not quite as good as Go, but you can make .NET apps that do quite a lot in under 20MB.

And sizes will be going quite a bit lower with NativeAOT this year.

https://www.awise.us/2021/06/05/smallest-dotnet.html

chaircher• 4 years ago

"...narp?"

Angostura• 4 years ago

No luck caching them proxies then?

anon856• 4 years ago

Just the one actually

imgabe• 4 years ago

Not Another Reverse Proxy!

9wzYQbTYsAIc10• 4 years ago

YARP is yet a another example of how C# is becoming a dominant systems language.

The ease with which you can build a tailor-made reverse proxy is pretty amazing.

BeefWellington4• 4 years ago

I guess I have to ask: What exactly is the use case for a tailor made reverse proxy? What customizations do people typically want to offload to the reverse proxy?

9wzYQbTYsAIc10• 4 years ago

The main use case that comes to my mind is when you want to deploy a proxy in an environment where the developer needs full oversight of the proxy internals and doesn’t want to learn the particulars of configuring any given proxy software suite.

Additionally, YARP is cross-platform capable, so you can run the same proxy on Linux, macOS, and Windows. NGINX doesn’t even provide that, for example.

In terms of customizations, YARP is more like “what feature do you need to build in” than “how do I need to configure”. You can quickly build a simple reverse proxy and just about as easily setup a full load balancing solution, but the simple use case doesn’t need to include any of the code for the advanced use case.

Moto7451• 4 years ago

We have one at work. This came from a distrust of developers’ abilities to correctly configure Apache and NGINX and a desire for the ability to roll out company wide changes that affect reverse proxying or headers we always want to set or remove on each request cycle.

franga2000• 4 years ago

A common one are multi-tenant applications where you want to dynamically (depending on data in a database for example) route requests to different places (like docker containers).

The first specific example I can think of is JupyterHub - it handles user management and starting/stopping Jupyter Notebook servers, then provides a reverse proxy for users to access their notebook servers directly.

HdS84• 4 years ago

We have used this on a net core app when yarp was only a very basic half abandoned solution.

Basically, we needed to to auth on each request (can the user see this per a slightly complicated rights system) and we routed to automatically spin up containers,so discovery was also custom

jayd16• 4 years ago

Custom load balancing rules could be an obvious usecase.

ledgerdev• 4 years ago

yet a another example of how C# is becoming a dominant systems language

Perhaps a bit of a stretch. I am currently choose golang for a more systems like project because of startup time and gc pauses in c#/dotnet. Definitely nice to see nativeaot which should address the startup time issues.

oaiey6• 4 years ago

It is a stretch but a viable and reasonable contender. C# spans a wide range ... Which is a weakness but also it's greatest strength.

9wzYQbTYsAIc10• 4 years ago

Maybe a slight stretch to say that it is a dominant systems language, but not much of one to say that it is becoming one.

Microsoft made a huge organizational change to support their cross-platform initiatives.

lpcvoid• 4 years ago

C# is becoming a dominant systems language

In 2022 everything is a system programming language. Next on that list is Javascript, I am sure.

aaaaaaaaata• 4 years ago

JS wasn't sufficient, there, so we chose Go (Golang)

DeathArrow2• 4 years ago

In 2022 everything is a system programming language. Next on that list is Javascript, I am sure.

Yes but cool people will write their systems software in Typescript. :)

fnord123• 4 years ago

I don't know if 22k lines of C# and 100k lines of json is an easy project.

DeathArrow2• 4 years ago

YARP is yet a another example of how C# is becoming a dominant systems language.

It won't become a systems language until it will let you to directly access hardware and do memory management, it will have improved performance and it will be natively AOT compiled.

9wzYQbTYsAIc10• 4 years ago

It already is a systems language and has been since the outset. Managed code is the preference, but you can certainly run unmanaged code with direct memory access if you want to.

https://docs.microsoft.com/en-us/dotnet/csharp/language-refe...

https://github.com/MichalStrehovsky/zerosharp

paraxion• 4 years ago

My first thought is "wasn't that called ISA?"

I can't help but be wary of anything Microsoft announces that's open source. Without engaging in MS-bashing, I always wonder what their motivation is. Then again, part of me wants to believe there's good, avid coders working there.

CyanLite4• 4 years ago

1997 called and want their outdated MS opinion back.

MS is one of the largest open source contributors these days. .Net is open source and cross-platform. They even have an open source Linux distribution. They actively contribute to Rust, webAssembly, the Linux kernel, and Kubernetes.

heavyset_go• 4 years ago

Your "Microsoft <3's open source" mentality is also out of date[1][2][3].

[1] https://news.ycombinator.com/item?id=28975856

[2] https://keivan.io/the-day-appget-died/

[3] https://news.ycombinator.com/item?id=28794352

teddyh• 4 years ago

Yeah, right. This was two months ago: https://news.ycombinator.com/item?id=29579994

mukundesh• 4 years ago

Only available in .NET ecosystem, got excited after I read the title, but forgot Microsoft is Microsoft.

"YARP is a reverse proxy toolkit for building fast proxy servers in .NET using the infrastructure from ASP.NET and .NET."

throwuxiytayq2• 4 years ago

I don't get it, what do you even expect them to do? Write it in Java? It's MIT-licensed, you can rewrite it if you wish.

square_usual2• 4 years ago

Yeah - whatever language they chose it would be "only available for [that] ecosystem." At some point you've got to pick your home, not like you can write a 100% cross-language framework for anything.

pdpi• 4 years ago

It’s written in C#, probably because they use a bunch of C# internally for this sort of project (who’da thunk it?). That naturally restricts the project to .NET environments.

That line could easily have read “for building fast proxy servers in the JVM” or “for building fast proxy servers in node.js” or whatever else, and it would’ve still been just as restrictive.

maloo2• 4 years ago

Still more flexible than the "app" style proxies. And there is ongoing work to allow c export and not just imports in C#. Which means you could make it a library for any language, but of course with your own custom interface since you can't call the C# apis unless you export a function to C.

dustinmoris• 4 years ago

Worth noting that YARP (or as someone has eloquently described it as PRAY) here was another Microsoft project which basically killed a previous open source project which did the same thing:

https://github.com/proxykit/ProxyKit

damianh2• 4 years ago

We know there is an ongoing issue with MS's relationship with .NET OSS ecosystem, but in this case I am totally fine with this. I proved the need of a code-first, highly extensible/customisable reverse-proxy (vs other approaches with config only and/or scripting). I also discovered on my journey there where things that needed to happen in layers I couldn't control nor influence (e.g. HttpClient, Kestrel etc) that YARP team could get done. I expressed these things when I had a meet with the team.

Ultimately we got a solid product with a not-too-dissimilar API and I have one less thing to maintain :)

noduerme2• 4 years ago

> We found a bunch of internal teams at Microsoft who were either building a reverse proxy for their service or had been asking about APIs and tech for building one

I'm really curious, does Microsoft have a crew of anthropologists walking around to figure out which team is reinventing wheels?

amir734jj• 4 years ago

Microsoft employees here. No actually. It's probably via word of mouth that they realized people are reinventing the wheel.

noduerme2• 4 years ago

You know how barnacles attach to a whale, to clean it? Maybe you guys need to spin off a whale-cleaner startup =D [edit] I realized it's the fish that clean the barnacles off it. So maybe like that. Anyway I'm just saying that an organization that is carrying that much dead weight just on internal organization is probably desperate for some better method than word of mouth to identify stuff like that.

kaukas• 4 years ago

I did worked with MSFT for some time. Basically you can do your own stuff, until you need to go to production. And if you do all things right "per process" somebody will "glimps" into your architecture and maybe even code. And in most cases this particular individual has seen a lot and is in the position to identify patterns. TBH I quite enjoyed how their corp machinery is working in the cloud world.

Cthulhu_• 4 years ago

Honestly I think any company that exceeds a certain size could do with a full time team to investigate and solve NIH and duplication.

I mean Google reinvents chat every couple of years, and that's just the ones that come out in public <_<

seanp2k2• 4 years ago

Fundamentally I believe it’s a communication problem + a problem of “engineers gonna engineer” to launch the next Big Win™ for their team / resume.

If I were looking for an honest solution for the first part, I might start with a standardized way of classifying technical problems and solitons. Maybe then it would be possible to build a directory of sorts for existing solutions that could be referenced when the need for a solution arises anywhere within the company.

9wzYQbTYsAIc10• 4 years ago

I'm really curious, does Microsoft have a crew of anthropologists

Quite literally, yes. Microsoft research has (or at least had) anthropologists on crew.

rolandog• 4 years ago

That's actually cool! I feel it's great they do some introspective work, no matter the company size.

davidfowl6• 4 years ago

Typically platform teams like ours (.NET person here) gets to see what a wide variety of teams are doing or are trying to do. YARP was a case of that happening and it felt like a good opportunity to build something low level and extensible that could help other teams at Microsoft, the OSS community and could directly drive improvements into the .NET networking stack.

ThinkBeat• 4 years ago

I am late to the party here.

What is the purpose of a reverse proxy?

Reading online: security, load balancing, https seems to be mentioned.

It appears a bit to me that a reverse proxy is not doing what a web server used to do back in the days of IIS/Apache.

I see a lot of programs meant to operate on the web that use very simple http servers.

dwaite• 4 years ago

I think of a reverse proxy as more of a general architectural pattern - when you have cross-cutting concerns for an application with a relatively broad protocol (HTTP) you can implement them as a networking layer in front of the service(s). Indirection and abstraction are powerful tools in computing.

Common reasons for such a split:

1. Composing several different services into a single internet domain

2. Putting stateless or CPU-heavy workloads onto different infrastructure from long-lived, IO-intensive tasks

3. Variation of the above, allow for multiple server processes in server environments which can't scale up to single multi-threaded processes well (CRuby/CPython)

4. Split security concerns off onto a box which has a much smaller attack surface, such as a box meant to be deployed in a DMZ (examples would be HTTPS termination, authentication and authorization policy enforcement)

5. Caching of responses (this is Varnish's claim to fame)

6. Variation of the above, some CDNs work by hitting an otherwise private server for data, then replicating throughout the network for locality to end-users.

7. Application-specific behavior patching, such as adding new API endpoints or changing the behavior of existing ones

In many of these cases, people use something like NGINX, Apache or a commercial solution like an F5. In other cases (such as application-specific business logic) people will write their own code, perhaps in the future using this Microsoft project as a starting point.

littlecranky67• 4 years ago

to add to your list:

8) avoid cross-origin problems and prevent unnecessary OPTIONS preflights that result in uneeded roundtrips by bundling mutiple FEs+BEs into a single origin with different paths (as opposed to mutliple domains/origins).

rad_gruchalski• 4 years ago

Have a look at Traefik, Envoy, or Istio proxy. Load balancing, TLS termination, authorization and authentication would be most common use cases.

sandreas• 4 years ago

Reminds me of Hot Fuzz (2007): https://youtu.be/qR8c-pfMRqA?t=61

davidfowl6• 4 years ago

One thing I'd like to add as a potential differentiator as well is that YARP runs very well on Windows and because it's build on ASP.NET Core, can run inside of IIS and directly on HTTP.sys as well (which means we can take advantage of cool features like http.sys request delegation where possible https://github.com/microsoft/reverse-proxy/commit/b9c13dbde9...). This means you get platform portability AND deep platform integration for free.

Microsoft YARP

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