将AWS区块链服务和go-ethereum整合的方法是什么？

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AWS 区块链服务为 HTTP 和 WebSocket 协议提供终端节点，但需要 IAM 签名验证才能使用它们。

要使用 HTTP 终端节点，我只需通过 AWS SDK 在 http.RoundTripper 接口中对其进行签名。但是，如果我需要使用WebSocket端点，由于go-ethereum的限制，我只能通过rpc.DialWebsocketWithDialer传入一个websocket.Dialer结构，这意味着我无法通过实现接口来解决这个问题。

如何将 AWS Blockchain Service 的 WebSocket 终端节点与 go-ethereum 结合使用？

正确答案

通过阅读github.com/gorilla/websocket源码，我发现(*dialer) dialcontext函数中有一个逻辑将http.request指针传递到可定制的proxy函数中，这意味着我可以编写一个函数来执行以下操作：与 http.roundtripper 相同，用于注入标头。

websocket

package transport

import (
    "context"
    "crypto/sha256"
    "encoding/hex"
    "net/http"
    "net/url"
    "time"

    "github.com/aws/aws-sdk-go-v2/aws"
    "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
    "github.com/gorilla/websocket"
)

func newwebsocketdialer(config aws.config) (*websocket.dialer, error) {
    return &websocket.dialer{
        handshaketimeout: 45 * time.second,
        proxy: func(request *http.request) (*url.url, error) {
            credentials, err := config.credentials.retrieve(request.context())
            if err != nil {
                return nil, err
            }

            // because aws may sign some unrelated headers and cause authentication failure, you need to create a blank request.
            internalrequest, err := http.newrequest(http.methodget, request.url.string(), nil)
            if err != nil {
                return nil, err
            }

            header := request.header.clone()

            hash := sha256.new()

            signer := v4.newsigner()

            if err := signer.signhttp(context.background(), credentials, internalrequest, hex.encodetostring(hash.sum(nil)), "managedblockchain", config.region, time.now()); err != nil {
                return nil, err
            }

            request.header = internalrequest.header

            request.header.set("connection", header["connection"][0])
            request.header.set("sec-websocket-key", header["sec-websocket-key"][0])
            request.header.set("sec-websocket-version", header["sec-websocket-version"][0])
            request.header.set("upgrade", header["upgrade"][0])

            return http.proxyfromenvironment(request)
        },
    }, nil
}

http

package transport

import (
    "compress/gzip"
    "context"
    "crypto/sha256"
    "encoding/base64"
    "encoding/hex"
    "io"
    "net/http"
    "time"

    "github.com/aws/aws-sdk-go-v2/aws"
    "github.com/aws/aws-sdk-go-v2/aws/signer/v4"
)

var _ http.RoundTripper = &httpRoundTripper{}

type httpRoundTripper struct {
    config aws.Config
}

func (h httpRoundTripper) RoundTrip(request *http.Request) (*http.Response, error) {
    credentials, err := h.config.Credentials.Retrieve(request.Context())
    if err != nil {
        return nil, err
    }

    internalRequest := request.Clone(request.Context())

    bodyReader, err := request.GetBody()
    if err != nil {
        return nil, err
    }

    hash := sha256.New()

    if _, err := io.Copy(hash, bodyReader); err != nil {
        return nil, err
    }

    signer := v4.NewSigner()
    if err := signer.SignHTTP(context.Background(), credentials, internalRequest, hex.EncodeToString(hash.Sum(nil)), "managedblockchain", h.config.Region, time.Now()); err != nil {
        return nil, err
    }

    response, err := h.config.HTTPClient.Do(internalRequest)
    if err != nil {
        return nil, err
    }

    if response.Header.Get("Content-Type") == "gzip" {
        gzipReader, err := gzip.NewReader(base64.NewDecoder(base64.StdEncoding, response.Body))
        if err != nil {
            return nil, err
        }

        request.Header.Set("Content-Type", "application/json")

        response.Body = gzipReader
    }

    return response, nil
}

func NewHttpRoundTripper(cfg aws.Config) http.RoundTripper {
    return httpRoundTripper{
        config: cfg,
    }
}

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