rpc: make HTTP RPC timeouts configurable, raise defaults (#17240)

* rpc: Make HTTP server timeout values configurable

* rpc: Remove flags for setting HTTP Timeouts, configuring via .toml is sufficient.

* rpc: Replace separate constants with a single default struct.

* rpc: Update HTTP Server Read and Write Timeouts to 30s.

* rpc: Remove redundant NewDefaultHTTPTimeouts function.

* rpc: document HTTPTimeouts.

* rpc: sanitize timeout values for library use

rpc/http.go

@@ -31,6 +31,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/go-ethereum/log"
 	"github.com/rs/cors"
 )
 
@@ -66,6 +67,38 @@ func (hc *httpConn) Close() error {
 	return nil
 }
 
+// HTTPTimeouts represents the configuration params for the HTTP RPC server.
+type HTTPTimeouts struct {
+	// ReadTimeout is the maximum duration for reading the entire
+	// request, including the body.
+	//
+	// Because ReadTimeout does not let Handlers make per-request
+	// decisions on each request body's acceptable deadline or
+	// upload rate, most users will prefer to use
+	// ReadHeaderTimeout. It is valid to use them both.
+	ReadTimeout time.Duration
+
+	// WriteTimeout is the maximum duration before timing out
+	// writes of the response. It is reset whenever a new
+	// request's header is read. Like ReadTimeout, it does not
+	// let Handlers make decisions on a per-request basis.
+	WriteTimeout time.Duration
+
+	// IdleTimeout is the maximum amount of time to wait for the
+	// next request when keep-alives are enabled. If IdleTimeout
+	// is zero, the value of ReadTimeout is used. If both are
+	// zero, ReadHeaderTimeout is used.
+	IdleTimeout time.Duration
+}
+
+// DefaultHTTPTimeouts represents the default timeout values used if further
+// configuration is not provided.
+var DefaultHTTPTimeouts = HTTPTimeouts{
+	ReadTimeout:  30 * time.Second,
+	WriteTimeout: 30 * time.Second,
+	IdleTimeout:  120 * time.Second,
+}
+
 // DialHTTPWithClient creates a new RPC client that connects to an RPC server over HTTP
 // using the provided HTTP Client.
 func DialHTTPWithClient(endpoint string, client *http.Client) (*Client, error) {
@@ -161,15 +194,30 @@ func (t *httpReadWriteNopCloser) Close() error {
 // NewHTTPServer creates a new HTTP RPC server around an API provider.
 //
 // Deprecated: Server implements http.Handler
-func NewHTTPServer(cors []string, vhosts []string, srv *Server) *http.Server {
+func NewHTTPServer(cors []string, vhosts []string, timeouts HTTPTimeouts, srv *Server) *http.Server {
 	// Wrap the CORS-handler within a host-handler
 	handler := newCorsHandler(srv, cors)
 	handler = newVHostHandler(vhosts, handler)
+
+	// Make sure timeout values are meaningful
+	if timeouts.ReadTimeout < time.Second {
+		log.Warn("Sanitizing invalid HTTP read timeout", "provided", timeouts.ReadTimeout, "updated", DefaultHTTPTimeouts.ReadTimeout)
+		timeouts.ReadTimeout = DefaultHTTPTimeouts.ReadTimeout
+	}
+	if timeouts.WriteTimeout < time.Second {
+		log.Warn("Sanitizing invalid HTTP write timeout", "provided", timeouts.WriteTimeout, "updated", DefaultHTTPTimeouts.WriteTimeout)
+		timeouts.WriteTimeout = DefaultHTTPTimeouts.WriteTimeout
+	}
+	if timeouts.IdleTimeout < time.Second {
+		log.Warn("Sanitizing invalid HTTP idle timeout", "provided", timeouts.IdleTimeout, "updated", DefaultHTTPTimeouts.IdleTimeout)
+		timeouts.IdleTimeout = DefaultHTTPTimeouts.IdleTimeout
+	}
+	// Bundle and start the HTTP server
 	return &http.Server{
 		Handler:      handler,
-		ReadTimeout:  5 * time.Second,
-		WriteTimeout: 10 * time.Second,
-		IdleTimeout:  120 * time.Second,
+		ReadTimeout:  timeouts.ReadTimeout,
+		WriteTimeout: timeouts.WriteTimeout,
+		IdleTimeout:  timeouts.IdleTimeout,
 	}
 }