feat: module circuit breaker (#14521)

Co-authored-by: Aaron Craelius <aaron@regen.network>
Co-authored-by: Julien Robert <julien@rbrt.fr>
Co-authored-by: Sam Ricotta <samanthalricotta@gmail.com>
Co-authored-by: samricotta <37125168+samricotta@users.noreply.github.com>
Co-authored-by: Facundo Medica <14063057+facundomedica@users.noreply.github.com>

baseapp/baseapp.go

@@ -431,6 +431,12 @@ func (app *BaseApp) setState(mode runTxMode, header cmtproto.Header) {
 	}
 }
 
+// SetCircuitBreaker sets the circuit breaker for the BaseApp.
+// The circuit breaker is checked on every message execution to verify if a transaction should be executed or not.
+func (app *BaseApp) SetCircuitBreaker(cb CircuitBreaker) {
+	app.msgServiceRouter.SetCircuit(cb)
+}
+
 // GetConsensusParams returns the current consensus parameters from the BaseApp's
 // ParamStore. If the BaseApp has no ParamStore defined, nil is returned.
 func (app *BaseApp) GetConsensusParams(ctx sdk.Context) cmtproto.ConsensusParams {

baseapp/circuit.go

@@ -0,0 +1,10 @@
+package baseapp
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+// CircuitBreaker is an interface that defines the methods for a circuit breaker.
+type CircuitBreaker interface {
+	IsAllowed(ctx sdk.Context, typeURL string) bool
+}

baseapp/msg_service_router.go

@@ -26,6 +26,7 @@ type MessageRouter interface {
 type MsgServiceRouter struct {
 	interfaceRegistry codectypes.InterfaceRegistry
 	routes            map[string]MsgServiceHandler
+	circuitBreaker    CircuitBreaker
 }
 
 var _ gogogrpc.Server = &MsgServiceRouter{}
@@ -37,6 +38,10 @@ func NewMsgServiceRouter() *MsgServiceRouter {
 	}
 }
 
+func (msr *MsgServiceRouter) SetCircuit(cb CircuitBreaker) {
+	msr.circuitBreaker = cb
+}
+
 // MsgServiceHandler defines a function type which handles Msg service message.
 type MsgServiceHandler = func(ctx sdk.Context, req sdk.Msg) (*sdk.Result, error)
 
@@ -128,6 +133,13 @@ func (msr *MsgServiceRouter) RegisterService(sd *grpc.ServiceDesc, handler inter
 				}
 			}
 
+			if msr.circuitBreaker != nil {
+				msgURL := sdk.MsgTypeURL(msg)
+				if !msr.circuitBreaker.IsAllowed(ctx, msgURL) {
+					return nil, fmt.Errorf("circuit breaker disables execution of this message: %s", msgURL)
+				}
+			}
+
 			// Call the method handler from the service description with the handler object.
 			// We don't do any decoding here because the decoding was already done.
 			res, err := methodHandler(handler, ctx, noopDecoder, interceptor)