I would like to retry HTTPS requests with HTTP requests if there is a

ConnectException

. Is the code below correct or is there a better way to do this?

client.install("HttpsToHttp") {
    requestPipeline.intercept(HttpRequestPipeline.Before) {
        val requestBuilder = this.context
        try {
            proceedWith(it)
        } catch (exception: ConnectException) {
            if (requestBuilder.url.protocol == URLProtocol.HTTPS) {
                requestBuilder.url.protocol = URLProtocol.HTTP
                proceedWith(requestPipeline.execute(requestBuilder, it)) // not sure if this is correct
            } else {
                throw exception
            }
        }
    }
}

Hi @Thomas, sorry for the delay. It doesn't look right for me. Probably you can grab idea from the

HttpRedirect

feature: https://github.com/ktorio/ktor/blob/b66e3072865de0bff9e6514a5d19cfc404985156/ktor-client/ktor-client-core/common/src/io/ktor/client/features/HttpRedirect.kt#L86

Hi @e5l, thanks for the link. I tried to create a HttpSend interceptor like below, but the code does not appear to be reached. I think the ssl exception is thrown earlier.

clientConfig.install("HttpsToHttp") {
    feature(HttpSend)!!.intercept { origin, context ->
        // the code below is not even reached.
        try {
            execute(context)
        } catch (throwable: Throwable) {
            TODO()
        }
    }
}

could you share the stacktrace?

Here is the exception. Looks like it is thrown here: https://github.com/ktorio/ktor/blob/b66e3072865de0bff9e6514a5d19cfc404985156/ktor-client/ktor-client-core/common/src/io/ktor/client/features/HttpSend.kt#L79 So that means it does not reach the interceptors a few lines lower in HttpSend.

But it should. Could you try to catch the exception in the

receivePipeline

? You can find it in

client.receivePipeline

Do you mean like this?

clientConfig.install("HttpsToHttp") {
    receivePipeline.intercept(HttpReceivePipeline.Before) {
        TODO()
    }
}

The

TODO()

is not reached here either, the ssl exception is still thrown like before

nope, I mean intercept both independently

If I add your code then I can still not catch the exception. I don’t understand what you mean by intercepting both independently. Do you mean I need to intercept HttpSend like before and add the code in your comment using the receivePipeline as well?

Exactly

So like this?

Trying to figure it out.

@e5l that is great! I can confirm it catches the exception. Do you know how to retry the request (after modifying it) in the catch block?

Nope, but you can store the flag outside sendPipeline interceptor and check it in send feature interceptor

I tried the following but it throws an IllegalStateException with error message check failed.