Backend manipulation based on condition

[rast1025]

I'm trying to configure my krakend.json using sequential proxy so that based on my backend's status code I can make one more request to another backend. Ex: If my 1st backend answers 201, I want to make request to 2nd backed, but if it answers 200, to another. Can I do it using krakend?

"backend": [
        {
          "url_pattern": "/api/verify",
          "encoding": "json",
          "host": "127.0.0.1:8081",
          "method": "GET",
          "group": "limits",
          "extra_config":{
            "github.com/devopsfaith/krakend-cel": [
              {
                "check_expr": "resp_data.limits.is_valid"
              }
            ]
          }
        },
        {
          "url_pattern": "/increase",
          "encoding": "json",
          "host": "127.0.0.1:8081",
          "method": "PUT",
          "group": "response"
        },
        {
          "url_pattern": "/decrease",
          "encoding": "json",
          "host": "127.0.0.1:8081",
          "method": "PUT",
          "group": "limits"
        }

      ]

[kpacha]

@rast1025 the usage of the status code as you described is not what your example shows.

the sequential response allows you to use elements of the previous response, so maybe you could combine it with some lua.

you can use no-op pipes for checking the status code and take a decision as your described or you can implement your example with this config:

    {
        "endpoint": "/your-endpoint",
        "extra_config": {
            "github.com/devopsfaith/krakend/proxy": { "sequential": true }
        },
        "backend": [
            {
                "url_pattern": "//api/verify",
                "host": ["http://host1.tld"],
                "extra_config": {
                    "github.com/devopsfaith/krakend-lua/proxy/backend": {
                        "sources": [ "verify.lua" ],
                        "post": "check_response(response.load())",
                        "allow_open_libs": true
                    }
                }
            },
            {
                "url_pattern": "/{resp0_action}",
                "host": ["http://host2.tld"]
            }
        ]
    }

and this lua snippet:

function check_response( resp )
    local responseData = resp:data()
    local limits = responseData:get("limits")
    if limits:get("is_valid")
    then
        responseData:set("action", "increase")
    else
        responseData:set("action", "decrease")
    end
end

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