(change) Improve error handling in case flag is not found by relay proxy

[Yaroslav-Kovalchyk-Imprivata]

Motivation

I'm trying to get flag value from relay proxy using OpenFeature SDK and dev.openfeature.contrib.providers.gofeatureflag.GoFeatureFlagProvider and getting unclear error message in log:

2023-03-20 13:38:26.397 ERROR 2146891 --- [nio-8081-exec-3] dev.openfeature.sdk.OpenFeatureClient : Unable to correctly evaluate flag with key 'demo.feature-b'

dev.openfeature.sdk.exceptions.GeneralError: unknown error while retrieving flag demo.feature-b at dev.openfeature.contrib.providers.gofeatureflag.GoFeatureFlagProvider.resolveEvaluationGoFeatureFlagProxy(GoFeatureFlagProvider.java:224) ~[go-feature-flag-0.2.3.jar:na] at dev.openfeature.contrib.providers.gofeatureflag.GoFeatureFlagProvider.getBooleanEvaluation(GoFeatureFlagProvider.java:124) ~[go-feature-flag-0.2.3.jar:na] at dev.openfeature.sdk.OpenFeatureClient.createProviderEvaluation(OpenFeatureClient.java:168) ~[sdk-1.3.0.jar:na] at dev.openfeature.sdk.OpenFeatureClient.evaluateFlag(OpenFeatureClient.java:134) ~[sdk-1.3.0.jar:na] at dev.openfeature.sdk.OpenFeatureClient.getBooleanDetails(OpenFeatureClient.java:211) ~[sdk-1.3.0.jar:na] at dev.openfeature.sdk.OpenFeatureClient.getBooleanDetails(OpenFeatureClient.java:205) ~[sdk-1.3.0.jar:na] at dev.openfeature.sdk.OpenFeatureClient.getBooleanValue(OpenFeatureClient.java:189) ~[sdk-1.3.0.jar:na] at com.demo.openfeature.service.HelloService.sayHello(HelloService.java:21) ~[main/:na] at com.demo.openfeature.controller.HelloController.sayHello(HelloController.java:24) ~[main/:na]

After debugging the GoFeatureFlagProvider I found, that it sends GET request http://127.0.0.1:1031/v1/feature/demo.feature-a/eval It is strange, but error response comes with 200 OK status. Response body contains following error:

{"trackEvents":true,"variationType":"SdkDefault","failed":true,"version":"","reason":"ERROR","errorCode":"FLAG_NOT_FOUND","value":false,"cacheable":false}

Provider attempts to parse this response in that way: GoFeatureFlagResponse goffResp = responseMapper.readValue(body, GoFeatureFlagResponse.class);

And gets parsing exception, that result in that unclear log message.

Requirements

Would be great to have error response with error status code and with meaningful and easy to understand message in logs.

[thomaspoignant]

@Yaroslav-Kovalchyk-Imprivata thanks for raising this issue.

1st, we are sending an HTTP 200 because the relay proxy is working as expected but the flag evaluation itself has returned an error.

I would check what happened in the java SDK and provide a fix. I will let you know as soon as I have more information.

[thomaspoignant]

@Yaroslav-Kovalchyk-Imprivata I've opened a PR to make it more explicit. You can check it https://github.com/thomaspoignant/go-feature-flag/issues/581

[thomaspoignant]

A new version of the provider as been released and will be soon available in maven repository.

[Yaroslav-Kovalchyk-Imprivata]

Thank you, @thomaspoignant!