Nonsensical errors on connection failure

[hchagen]

Preflight checklist

• I could not find a solution in the existing issues, docs, nor discussions.
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Describe the bug

So, I'm not sure if I should report this here, as it's very minor, but if a request to OidcApiService (or probably most the APIs) fails due to a timeout or failure in dns resolving or connection refused or whatever, thus not returning a body, the error reported from the API client is

json: cannot unmarshal object into Go struct field ErrorOAuth2.error of type string

I feel like this could be greatly improved upon by simply checking the type of the error returned, or even reading the response into a buffer and checking its length before decoding - it would be nice to have a less nonsensical error message here, makes it a lot easier to debug when things fail!

Reproducing the bug

Use the SDK (I'm currently on "github.com/ory/client-go" v1.1.21), set it up towards a non-existent host - the specific call that fails for me is most often:

oryClient.OidcApi.DiscoverOidcConfiguration(oryClient.AuthCtx(ctx)).Execute()

and watch the magic unfold!

Relevant log output

2023-03-15 17:57:35.848 [    info] auth-sidecar.auth-sidecar-service-server (leafId=auth-sidecar-service-server, service.env=LOCAL, service.name=auth-sidecar, service.type=go, service.version=web@2914:257e1d77ba1c214e1b66331c9faf6899034ddfc4:origin/feat/grpc-keto) Unable to setup ory client: json: cannot unmarshal object into Go struct field ErrorOAuth2.error of type string, falling back to mock client
2023-03-15 17:57:35.929 [    info] auth-sidecar.auth-sidecar-service-server (leafId=auth-sidecar-service-server, service.env=LOCAL, service.name=auth-sidecar, service.type=go, service.version=web@2914:257e1d77ba1c214e1b66331c9faf6899034ddfc4:origin/feat/grpc-keto) Unable to setup ory client: json: cannot unmarshal object into Go struct field ErrorOAuth2.error of type string, falling back to mock client
2023-03-15 17:57:36.023 [    info] auth-sidecar.auth-sidecar-service-server (leafId=auth-sidecar-service-server, service.env=LOCAL, service.name=auth-sidecar, service.type=go, service.version=web@2914:257e1d77ba1c214e1b66331c9faf6899034ddfc4:origin/feat/grpc-keto) Unable to setup ory client: json: cannot unmarshal object into Go struct field ErrorOAuth2.error of type string, falling back to mock client

### Relevant configuration

```yml
I'm using ory cloud right now, so it's whatever we set up there, I don't think it's particularly relevant :)

Version

v1.1.21

On which operating system are you observing this issue?

Linux

In which environment are you deploying?

Ory Network

Additional Context

I think that's most of it, it should be fairly straightforward to fix, I think. Unless, of course, it's caused by the OpenAPI generator, which it very well might be!

[aeneasr]

Thank you for the report! I do believe that the problem here is in fact the OpenAPI generated code :(

[ThisDevDane]

I'm hitting this problem on the oryClient.OAuth2Api.Introspect2Token(...) call, sort of making ory completely useless to me :/ Am on the latest tag 'v1.1.23'

edit: okay not completely useless as I realized I could just red from the response directly, but I can say that this occurs even if the message does have a body