Support passing of headers to all Engine API calls (#11330)

* Support passing of headers to all Engine API calls

* Update execution headers example

Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>

cmd/beacon-chain/execution/options.go

@@ -23,9 +23,11 @@ func FlagOptions(c *cli.Context) ([]execution.Option, error) {
 	if err != nil {
 		return nil, errors.Wrap(err, "could not read JWT secret file for authenticating execution API")
 	}
+	headers := strings.Split(c.String(flags.ExecutionEngineHeaders.Name), ",")
 	opts := []execution.Option{
 		execution.WithHttpEndpoint(endpoint),
 		execution.WithEth1HeaderRequestLimit(c.Uint64(flags.Eth1HeaderReqLimit.Name)),
+		execution.WithHeaders(headers),
 	}
 	if len(jwtSecret) > 0 {
 		opts = append(opts, execution.WithHttpEndpointAndJWTSecret(endpoint, jwtSecret))

cmd/beacon-chain/flags/base.go

@@ -32,6 +32,12 @@ var (
 		Usage: "An execution client http endpoint. Can contain auth header as well in the format",
 		Value: "http://localhost:8551",
 	}
+	// ExecutionEngineHeaders defines a list of HTTP headers to send with all execution client requests.
+	ExecutionEngineHeaders = &cli.StringFlag{
+		Name: "execution-headers",
+		Usage: "A comma separated list of key value pairs to pass as HTTP headers for all execution " +
+			"client calls. Example: --execution-headers=key1=value1,key2=value2",
+	}
 	// Deprecated: HTTPWeb3ProviderFlag is a deprecated flag and is an alias for the ExecutionEngineEndpoint flag.
 	HTTPWeb3ProviderFlag = &cli.StringFlag{
 		Name:   "http-web3provider",

cmd/beacon-chain/main.go

@@ -38,6 +38,7 @@ import (
 var appFlags = []cli.Flag{
 	flags.DepositContractFlag,
 	flags.ExecutionEngineEndpoint,
+	flags.ExecutionEngineHeaders,
 	flags.HTTPWeb3ProviderFlag,
 	flags.ExecutionJWTSecretFlag,
 	flags.RPCHost,

cmd/beacon-chain/usage.go

@@ -107,6 +107,7 @@ var appHelpFlagGroups = []flagGroup{
 			flags.GRPCGatewayPort,
 			flags.GPRCGatewayCorsDomain,
 			flags.ExecutionEngineEndpoint,
+			flags.ExecutionEngineHeaders,
 			flags.HTTPWeb3ProviderFlag,
 			flags.ExecutionJWTSecretFlag,
 			flags.SetGCPercent,