How to route requests to a dynamic endpoint on kong api-gateway - api-gateway

Question

I have a service named alpha (created using python-django) that runs on http://127.0.0.1:9000 and has these two endpoings
/health returns {"health": "OK"} status 200
/codes/<str:code> returns {"code": code} status 200
I also have a kong api-gateway in the db-less declarative mode that runs on localhost port 80
in kong.yaml I have two services
services:
- name: local-alpha-health
url: http://host.docker.internal:9000/health
routes:
- name: local-alpha-health
methods:
- GET
paths:
- /alpha/health
strip_path: true
- name: local-alpha-code
url: http://host.docker.internal:9000/code/ # HOW TO WRITE THIS PART???
routes:
- name: local-alpha-code
methods:
- GET
paths:
- /alpha/code/(?<appcode>\d+) # Is this right???
strip_path: true
If I send a GET request to http://127.0.0.1/alpha/health it returns {"health": "OK"} status 200 which shows kong is working.
I want to send a request such as http://127.0.0.1/alpha/code/123 and I expect to receive {"code": 123} status 200 but I don't know how to setup kong.yaml file to do this. If I send a request to http://127.0.0.1/alpha/code/123 I get 404 from (from the alpha django application) which means kong is routing the request to alpha service but if I send a request to http://127.0.0.1/alpha/code/abc I get {"message": "no Route matched with those values"} which shows the regex is working
I could do this
services:
- name: local-alpha-health
url: http://host.docker.internal:9000/
routes:
- name: local-alpha-health
methods:
- GET
paths:
- /alpha
strip_path: true
Then a request sent to http://127.0.0.1/alpha/code/123 would go to ``http://127.0.0.1:9000/code/123` but I cannot control with regex
Any idea How to route requests to a dynamic endpoint on kong api-gateway?
This content seems related but cannot figure it out how to set it up
https://docs.konghq.com/gateway-oss/2.5.x/proxy/

Answer 1

Note that a request like http://127.0.0.1/alpha/code/abc will indeed not match the rule you have added, because of the \d+ (which matches one or more digits). Also, http://127.0.0.1/alpha/code/123 will reach the upstream as a request to /, since you have strip_path set to true.
I have tested your example with some minor tweaks to proxy to a local httpbin service, which has a similar endpoint (/status/<code>).
Start a local httpbin service:
$ docker run --rm -d -p "8080:80" kennethreitz/httpbin
Start Kong with the following config:
_format_version: "2.1"
services:
- name: local-alpha-code
url: http://localhost:8080
routes:
- name: local-mockbin-status
methods:
- GET
paths:
- /status/(?<appcode>\d+)
strip_path: false
Note that strip_path is set to false, so the entire matching path is proxied to the upstream.
Test it out with:
$ http :8000/status/200
HTTP/1.1 200 OK