如何将 AWS 区块链服务与 go-ethereum 一起使用？

Question

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

要使用 HTTP 端点，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 区块链服务的 WebSocket 端点与 go-ethereum 结合使用？

Answer 1

通过阅读github.com/gorilla/websocket 的源代码，我发现函数中有一个逻辑(*Dialer) DialContext将 http.Request 指针传递给可定制的函数，这意味着我可以编写一个与forProxy做同样事情的函数http.RoundTripper注入标头。WebSocketpackage transportimport (    "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}HTTPpackage transportimport (    "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,    }}