ClientIP predicate is giving inconsistent results about skipper

[sepehrdaddev]

@szuecs yes, thats clear that :: is not a valid IP but the reason why I created an issue is that, I would expect it to throw an error during the predicate creation saying that its not a valid IP rather than accepting it and then not being able to enforce it (in the test, the predicate gets created with :: successfully without any errors).

[sepehrdaddev]

I think, this is an error case that hasn't been covered by the library which is important when using skipper as a library but its not something that causes a huge problem, its more a usability issue than anything else (I see Sandor already created a patch for it).

[sepehrdaddev]

similar to #2848

[szuecs]

But :: is not a valid client IP.

The input data is like here:

% go doc http.Request.RemoteAddr
package http // import "net/http"

type Request struct {
    // RemoteAddr allows HTTP servers and other software to record the network address
    // that sent the request, usually for logging. This field is not filled in by
    // ReadRequest and has no defined format. The HTTP server in this package sets
    // RemoteAddr to an "IP:port" address before invoking a handler. This field is
    // ignored by the HTTP client.
    RemoteAddr string

Of course in local tests you can define it different but you won't be able to create a call to http.Server, such that this will lead to :: as RemoteAddr.

[AlexanderYastrebov]

the fuzzer panics when the ip address is ::

Hm, is there a panic in skipper code?

[sepehrdaddev]

@AlexanderYastrebov so, I wrote the fuzzer in a way that if it finds something that is not correct, it would panic, this is because the fuzzer only detects panics, so anything unexpected must panic to be able to detect it.

so no, there is no panic in skipper code.

[AlexanderYastrebov]

I think we can trust RemoteAddr as it comes from the server. Do we need to fix this at all?

[szuecs]

I think it's fine to fix it because it's a generic function in skipper's net package.