[AppGate] Add the MaxDelegatedGateways parameter (#109)

config.yml

@@ -79,6 +79,8 @@ genesis:
           - amount: "10000"
             denom: upokt
     application:
+      params:
+        maxDelegatedGateways: 7
     applicationList:
       - address: pokt1mrqt5f7qh8uxs27cjm9t7v9e74a9vvdnq5jva4
         stake:

docs/static/openapi.yml

@@ -46735,6 +46735,13 @@ paths:
               params:
                 description: params holds all the parameters of this module.
                 type: object
+                properties:
+                  max_delegated_gateways:
+                    type: integer
+                    format: int64
+                    title: >-
+                      The maximum number of gateways an application can delegate
+                      trust to
             description: >-
               QueryParamsResponse is response type for the Query/Params RPC
               method.
@@ -77831,6 +77838,11 @@ definitions:
     type: object
   pocket.application.Params:
     type: object
+    properties:
+      max_delegated_gateways:
+        type: integer
+        format: int64
+        title: The maximum number of gateways an application can delegate trust to
     description: Params defines the parameters for the module.
   pocket.application.QueryAllApplicationResponse:
     type: object
@@ -78004,6 +78016,13 @@ definitions:
       params:
         description: params holds all the parameters of this module.
         type: object
+        properties:
+          max_delegated_gateways:
+            type: integer
+            format: int64
+            title: >-
+              The maximum number of gateways an application can delegate trust
+              to
     description: QueryParamsResponse is response type for the Query/Params RPC method.
   pocket.shared.ApplicationServiceConfig:
     type: object

proto/pocket/application/params.proto

@@ -8,5 +8,6 @@ option go_package = "pocket/x/application/types";
 // Params defines the parameters for the module.
 message Params {
   option (gogoproto.goproto_stringer) = false;
-
+
+  int64 max_delegated_gateways = 1 [(gogoproto.jsontag) = "max_delegated_gateways"]; // The maximum number of gateways an application can delegate trust to
 }

testutil/keeper/application.go

@@ -24,6 +24,7 @@ import (
 // StakedGatewayMap is used to mock whether a gateway is staked or not for use
 // in the application's mocked gateway keeper. This enables the tester to
 // control whether a gateway is "staked" or not and whether it can be delegated to
+// WARNING: Using this map may cause issues if running multiple tests in parallel
 var StakedGatewayMap = make(map[string]struct{})
 
 func ApplicationKeeper(t testing.TB) (*keeper.Keeper, sdk.Context) {

x/application/keeper/msg_server_delegate_to_gateway.go

@@ -34,6 +34,13 @@ func (k msgServer) DelegateToGateway(goCtx context.Context, msg *types.MsgDelega
 		return nil, sdkerrors.Wrapf(types.ErrAppGatewayNotFound, "gateway not found with address: %s", msg.GatewayAddress)
 	}
 
+	// Ensure the application is not already delegated to the maximum number of gateways
+	maxDelegatedParam := k.GetParams(ctx).MaxDelegatedGateways
+	if int64(len(app.DelegateeGatewayAddresses)) >= maxDelegatedParam {
+		logger.Info("Application already delegated to maximum number of gateways: %d", maxDelegatedParam)
+		return nil, sdkerrors.Wrapf(types.ErrAppMaxDelegatedGateways, "application already delegated to %d gateways", maxDelegatedParam)
+	}
+
 	// Check if the application is already delegated to the gateway
 	for _, gatewayAddr := range app.DelegateeGatewayAddresses {
 		if gatewayAddr == msg.GatewayAddress {

x/application/keeper/msg_server_delegate_to_gateway_test.go

@@ -136,7 +136,7 @@ func TestMsgServer_DelegateToGateway_FailDuplicate(t *testing.T) {
 
 	// Attempt to delegate the application to the gateway again
 	_, err = srv.DelegateToGateway(wctx, delegateMsg2)
-	require.Error(t, err)
+	require.ErrorIs(t, err, types.ErrAppAlreadyDelegated)
 	foundApp, isAppFound = k.GetApplication(ctx, appAddr)
 	require.True(t, isAppFound)
 	require.Equal(t, 1, len(foundApp.DelegateeGatewayAddresses))
@@ -177,8 +177,76 @@ func TestMsgServer_DelegateToGateway_FailGatewayNotStaked(t *testing.T) {
 
 	// Attempt to delegate the application to the unstaked gateway
 	_, err = srv.DelegateToGateway(wctx, delegateMsg)
-	require.Error(t, err)
+	require.ErrorIs(t, err, types.ErrAppGatewayNotFound)
 	foundApp, isAppFound := k.GetApplication(ctx, appAddr)
 	require.True(t, isAppFound)
 	require.Equal(t, 0, len(foundApp.DelegateeGatewayAddresses))
 }
+
+func TestMsgServer_DelegateToGateway_FailMaxReached(t *testing.T) {
+	k, ctx := keepertest.ApplicationKeeper(t)
+	srv := keeper.NewMsgServerImpl(*k)
+	wctx := sdk.WrapSDKContext(ctx)
+
+	// Generate an address for the application and gateway
+	appAddr := sample.AccAddress()
+	gatewayAddr := sample.AccAddress()
+	// Mock the gateway being staked via the staked gateway map
+	keepertest.StakedGatewayMap[gatewayAddr] = struct{}{}
+	t.Cleanup(func() {
+		delete(keepertest.StakedGatewayMap, gatewayAddr)
+	})
+
+	// Prepare the application
+	stakeMsg := &types.MsgStakeApplication{
+		Address: appAddr,
+		Stake:   &sdk.Coin{Denom: "upokt", Amount: sdk.NewInt(100)},
+		Services: []*sharedtypes.ApplicationServiceConfig{
+			{
+				ServiceId: &sharedtypes.ServiceId{Id: "svc1"},
+			},
+		},
+	}
+
+	// Stake the application & verify that the application exists
+	_, err := srv.StakeApplication(wctx, stakeMsg)
+	require.NoError(t, err)
+	_, isAppFound := k.GetApplication(ctx, appAddr)
+	require.True(t, isAppFound)
+
+	// Prepare the delegation message
+	delegateMsg := &types.MsgDelegateToGateway{
+		AppAddress:     appAddr,
+		GatewayAddress: gatewayAddr,
+	}
+
+	// Delegate the application to the max number of gateways
+	maxDelegatedParam := k.GetParams(ctx).MaxDelegatedGateways
+	for i := int64(0); i < k.GetParams(ctx).MaxDelegatedGateways; i++ {
+		// Prepare the delegation message
+		gatewayAddr := sample.AccAddress()
+		// Mock the gateway being staked via the staked gateway map
+		keepertest.StakedGatewayMap[gatewayAddr] = struct{}{}
+		t.Cleanup(func() {
+			delete(keepertest.StakedGatewayMap, gatewayAddr)
+		})
+		delegateMsg := &types.MsgDelegateToGateway{
+			AppAddress:     appAddr,
+			GatewayAddress: gatewayAddr,
+		}
+		// Delegate the application to the gateway
+		_, err = srv.DelegateToGateway(wctx, delegateMsg)
+		require.NoError(t, err)
+		// Check number of gateways delegated to is correct
+		foundApp, isAppFound := k.GetApplication(ctx, appAddr)
+		require.True(t, isAppFound)
+		require.Equal(t, int(i+1), len(foundApp.DelegateeGatewayAddresses))
+	}
+
+	// Attempt to delegate the application when the max is already reached
+	_, err = srv.DelegateToGateway(wctx, delegateMsg)
+	require.ErrorIs(t, err, types.ErrAppMaxDelegatedGateways)
+	foundApp, isAppFound := k.GetApplication(ctx, appAddr)
+	require.True(t, isAppFound)
+	require.Equal(t, maxDelegatedParam, int64(len(foundApp.DelegateeGatewayAddresses)))
+}

x/application/types/errors.go

@@ -8,12 +8,14 @@ import (
 
 // x/application module sentinel errors
 var (
-	ErrAppInvalidStake          = sdkerrors.Register(ModuleName, 1, "invalid application stake")
-	ErrAppInvalidAddress        = sdkerrors.Register(ModuleName, 2, "invalid application address")
-	ErrAppUnauthorized          = sdkerrors.Register(ModuleName, 3, "unauthorized application signer")
-	ErrAppNotFound              = sdkerrors.Register(ModuleName, 4, "application not found")
-	ErrAppInvalidServiceConfigs = sdkerrors.Register(ModuleName, 6, "invalid service configs")
-	ErrAppGatewayNotFound       = sdkerrors.Register(ModuleName, 7, "gateway not found")
-	ErrAppInvalidGatewayAddress = sdkerrors.Register(ModuleName, 8, "invalid gateway address")
-	ErrAppAlreadyDelegated      = sdkerrors.Register(ModuleName, 9, "application already delegated to gateway")
+	ErrAppInvalidStake                = sdkerrors.Register(ModuleName, 1, "invalid application stake")
+	ErrAppInvalidAddress              = sdkerrors.Register(ModuleName, 2, "invalid application address")
+	ErrAppUnauthorized                = sdkerrors.Register(ModuleName, 3, "unauthorized application signer")
+	ErrAppNotFound                    = sdkerrors.Register(ModuleName, 4, "application not found")
+	ErrAppInvalidServiceConfigs       = sdkerrors.Register(ModuleName, 6, "invalid service configs")
+	ErrAppGatewayNotFound             = sdkerrors.Register(ModuleName, 7, "gateway not found")
+	ErrAppInvalidGatewayAddress       = sdkerrors.Register(ModuleName, 8, "invalid gateway address")
+	ErrAppAlreadyDelegated            = sdkerrors.Register(ModuleName, 9, "application already delegated to gateway")
+	ErrAppMaxDelegatedGateways        = sdkerrors.Register(ModuleName, 10, "maximum number of delegated gateways reached")
+	ErrAppInvalidMaxDelegatedGateways = sdkerrors.Register(ModuleName, 11, "invalid MaxDelegatedGateways parameter")
 )

x/application/types/genesis_test.go

@@ -41,6 +41,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "valid genesis state",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -62,6 +65,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - zero app stake",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -82,6 +88,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - negative application stake",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -102,6 +111,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - wrong stake denom",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -122,6 +134,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - missing denom",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -142,6 +157,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - due to duplicated app address",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -162,6 +180,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - due to nil app stake",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -182,6 +203,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - due to missing app stake",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -202,6 +226,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - due to invalid delegatee pub key",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -222,6 +249,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - due to invalid delegatee pub keys",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -242,6 +272,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - service config not present",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address: addr1,
@@ -256,6 +289,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - empty service config",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address:                   addr1,
@@ -270,6 +306,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - service ID too long",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address: addr1,
@@ -286,6 +325,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - service name too long",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address: addr1,
@@ -305,6 +347,9 @@ func TestGenesisState_Validate(t *testing.T) {
 		{
 			desc: "invalid - service ID with invalid characters",
 			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 7,
+				},
 				ApplicationList: []types.Application{
 					{
 						Address: addr1,
@@ -318,6 +363,15 @@ func TestGenesisState_Validate(t *testing.T) {
 			},
 			valid: false,
 		},
+		{
+			desc: "invalid - MaxDelegatedGateways less than 1",
+			genState: &types.GenesisState{
+				Params: types.Params{
+					MaxDelegatedGateways: 0,
+				},
+			},
+			valid: false,
+		},
 
 		// this line is used by starport scaffolding # types/genesis/testcase
 	}

x/application/types/params.go

@@ -1,10 +1,14 @@
 package types
 
 import (
+	sdkerrors "cosmossdk.io/errors"
 	paramtypes "github.com/cosmos/cosmos-sdk/x/params/types"
 	"gopkg.in/yaml.v2"
 )
 
+// TODO: Revisit default param values
+const DefaultMaxDelegatedGateways int64 = 7
+
 var _ paramtypes.ParamSet = (*Params)(nil)
 
 // ParamKeyTable the param key table for launch module
@@ -14,7 +18,7 @@ func ParamKeyTable() paramtypes.KeyTable {
 
 // NewParams creates a new Params instance
 func NewParams() Params {
-	return Params{}
+	return Params{MaxDelegatedGateways: DefaultMaxDelegatedGateways}
 }
 
 // DefaultParams returns a default set of parameters
@@ -29,6 +33,9 @@ func (p *Params) ParamSetPairs() paramtypes.ParamSetPairs {
 
 // Validate validates the set of params
 func (p Params) Validate() error {
+	if p.MaxDelegatedGateways < 1 {
+		return sdkerrors.Wrapf(ErrAppInvalidMaxDelegatedGateways, "MaxDelegatedGateways param < 1: got %d", p.MaxDelegatedGateways)
+	}
 	return nil
 }