[REQ] envoy routes generator

[kratosmat]

import openapi to envoy gateway

every api manager has this capability but if you don't want to manage a big api manager you can use envoy as apigw but you shouldn't write the routes if you have the openapi of your backend. So I would like to gen routes from ooenapi doc.

Do you think it is possible? There is a way to create an envoy plugin?
Thanks.

[wing328]

i think it's possible

openapi generator can potentially generate a config file for Envoy based on certain information presented in the OpenAPI specification file.

is that something you can contribute?

i can show you some good starting points to create a new generator

[kratosmat]

Hello, absolutely yes, you can contribute. Thanks, Matteo Cusmai

…

On Wed, Mar 12, 2025 at 11:11 AM William Cheng ***@***.***> wrote: i think it's possible openapi generator can potentially generate a config file for Envoy based on certain information presented in the OpenAPI specification file. is that something you can contribute? i can show you some good starting points to create a new generator — Reply to this email directly, view it on GitHub <#20854 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABREXGTCPZ5CNJY6WNLSTDL2UAB5NAVCNFSM6AAAAABY256AOSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMJXGM2DMMJVGU> . You are receiving this because you authored the thread.Message ID: ***@***.***> [image: wing328]*wing328* left a comment (OpenAPITools/openapi-generator#20854) <#20854 (comment)> i think it's possible openapi generator can potentially generate a config file for Envoy based on certain information presented in the OpenAPI specification file. is that something you can contribute? i can show you some good starting points to create a new generator — Reply to this email directly, view it on GitHub <#20854 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABREXGTCPZ5CNJY6WNLSTDL2UAB5NAVCNFSM6AAAAABY256AOSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDOMJXGM2DMMJVGU> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[wing328]

for the petstore spec (https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/test/resources/3_0/petstore.yaml),

can you pick a few endpoints (e.g in Pet, User, Order) and show us what the output (envoy route config file) looks like?

we can then reverse engineer the generator

[kratosmat]

Hello,
Sorry for delay.

An example could be the following

Thanks

resources:

• "@type": type.googleapis.com/envoy.config.route.v3.RouteConfiguration
  name: local_route
  virtual_hosts:

  • name: local_service
    domains: ["*"]
    routes:

    Method-specific route for GET /api/hello

    • match:
      safe_regex:
      regex: "/api/pet/[0-9]+"
      headers:
      • name: ":method"
        exact_match: "GET"
        route:
        cluster: petstore_app_service

    Method-specific route for POST /api/hello

    • match:
      path: "/api/hello"
      headers:
      • name: ":method"
        exact_match: "POST"
        route:
        prefix_rewrite: "/hello"
        cluster: petstore_app_service

    Default route for other methods - returns 405 Method Not Allowed

    • match:
      path: "/api/hello"
      direct_response:
      status: 405
      body:
      inline_string: "Method Not Allowed"

    General route for other paths

    • match:
      prefix: "/"
      direct_response:
      status: 480

[oleksiybozhyk]

Hello all,

I'm also interested in this type of implementation, the base idea is to use routes.yaml for the path forwarding all other path respond with 404;
Please check my repo with sample implementation for envoy pet store example:
https://github.com/oleksiybozhyk/envoy-pet-store-example

Thank you!

[reineo]

This type of generator would be much more usable if it supported more advanced Envoy features such as Authorization filters. This is commonly supported in other API Gateways (Istio, Kong, ..) through custom OAS extensions.

Custom OAS extension from a Kong example:

x-kong-security-openid-connect:
  config:
    scopes_required: ["scope1", "scope2"]