Kong proxy cache plugin - X-Cache-Status is always Bypass when cache_control is enabled

Question

I have a registered service in Kong and currently trying to set up the proxy-cache plugin.

The plugin itself works fine when cache control is set to false, but when I enable it, the X-Cache-Status header is always Bypass.

The plugin configuration looks like this:

  plugins:
  - name: proxy-cache
    service: echo
    config: 
      response_code
      - 200
      - 301
      - 404
      request_method:
      - GET
      - HEAD
      content_type:
      - text/plain
      - application/json
      - application/json; charset=utf-8
      - text/plain; charset=utf-8
      cache_ttl: 300
      strategy: memory
      cache_control: true
      memory:
        dictionary_name: kong_db_cache

And the request looks like this:

curl --location --request GET 'http://localhost:8000/echo' --header 'Cache-Control: public, max-age=20'

I was experimenting with different Cache-Control values, registered also request-transformer plugin and was playing with headers there, but nothing seems to work.

Did anyone encounter this issue before? I'm pretty much stuck here and any kind of suggestion is more than welcome.

Answer 1

You have set the option

cache_control: true

So Kong will respect the Cache-Control behaviors defined in RFC7234

You need to have an cache header into the upstream answer. Or you should set it to false