Investigate GRPC-Web/JSON support in Ambassador

[plombardi89]

A number of users have asked for GRPC-Web/JSON transcoder support in Ambassador. We need to know how to integrate this into Ambassador before we proceed.

CoS

• A design for how the mapping feature would work has been agreed upon by the team.
• A prototype that supports the agreed design has been produced.
• A plan for next steps / release has been created or decided.

[richarddli]

See issue #411

[dvavili]

Is this targeted for a particular release? Would be good to have this.

[neilcarpenter]

Is this issue also tracking using gRPC-web with binary wire format (as opposed to JSON), which is enabled in Envoy with this filter?

[mprigge]

For what it's worth, I'm very interested to see Ambassador support this as well. I'm sure you're already aware of the support that's in envoy already. Not sure how hard it would be to have Ambassador support a configuration similar to this one. Is it just an issue of wrapping envoy configuration correctly or does it go deeper than that? I'm bleeding new to both Ambassador and Envoy, but it seems like calling the grpc_web filer is really the only thing missing (unlike the JSON transcoder, it doesn't really have any associated configuration).

[nigeltiany]

There hasn't been feedback on this. I also want to know the answer to @neilcarpenter 's question and if there is a short-term alternative with little modification that will get it to work.

[slamdev]

@nigeltiany you can build ambassador from sources and replace envoy.j2 with custom one, like here https://github.com/slamdev/catalog/tree/master/infra/ambassador/deploy

key parts are: to add grpc_web filter and grpc and cors mappings for the service

[nigeltiany]

I have built ambassador from that envoy.j2 file and it works. I didn't even have to configure cors mappings. Thank you @slamdev 👈 True hero right here.
Now, submitting a PR is easy because it's just a single new object with one line of code but how to write the end-to-end/unit tests. Is any of the maintainers @Ambassador available to look at this fix?

[richarddli]

@nigeltiany Would love to, although be warned that we've changed things up quite a bit in the (imminent) 0.50 ... so it's possible that your change won't just work in the next release. The current code is on the release/0.50.0 branch, if you want to take a look.

[richarddli]

See PR #1201, thank you to @rotemtam.

[kflynn]

gRPC-Web is supported in 0.52.0.

[shubhamranjan]

I can see that support for grpc-web transcoder has been implemented but what about grpc-json transcoder ? I am unable to find ambassador documentation regarding this.

For more info, have a look at this : https://www.envoyproxy.io/docs/envoy/latest/configuration/http_filters/grpc_json_transcoder_filter

[richarddli]

Not yet. There's an open issue for this I believe @shubhamranjan if you want to contribute a PR!

[shubhamranjan]

@richarddli I would love to contribute. Please lead me to the issue (issue link) for more insights and discussions. I was unable to find the issue.

[cyj5230]

Hello, I am looking for grpc-json transcoder support as well. Only found a closed issue #254 and this one. May I know the process of this feature?

[johannesehrhart]

Hi, is there any update on the grpc-json transcoder support?