From b84cabb8f4575c9ef62f41100cce5dba4cb14b67 Mon Sep 17 00:00:00 2001
From: Julien Robert <julien@rbrt.fr>
Date: Wed, 11 Sep 2024 21:12:03 +0200
Subject: [PATCH 1/3] refactor(server/v2): kill viper from server components

---
 server/v2/api/grpc/server.go        | 15 +++++++--------
 server/v2/api/grpcgateway/server.go | 11 +++++------
 server/v2/cometbft/config.go        | 14 --------------
 server/v2/cometbft/server.go        | 20 +++++++++++++-------
 server/v2/commands.go               |  2 +-
 server/v2/config.go                 |  8 +++-----
 server/v2/config_test.go            |  5 +++--
 server/v2/server.go                 | 15 +++++++--------
 server/v2/server_mock_test.go       |  4 +---
 server/v2/server_test.go            |  5 +++--
 server/v2/store/server.go           | 11 +++++------
 11 files changed, 48 insertions(+), 62 deletions(-)

diff --git a/server/v2/api/grpc/server.go b/server/v2/api/grpc/server.go
index b66be16da602..0003f2343222 100644
--- a/server/v2/api/grpc/server.go
+++ b/server/v2/api/grpc/server.go
@@ -12,7 +12,6 @@ import (
 
 	"github.com/cosmos/gogoproto/proto"
 	"github.com/spf13/pflag"
-	"github.com/spf13/viper"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
@@ -47,10 +46,10 @@ func New[T transaction.Tx](cfgOptions ...CfgOption) *Server[T] {
 
 // Init returns a correctly configured and initialized gRPC server.
 // Note, the caller is responsible for starting the server.
-func (s *Server[T]) Init(appI serverv2.AppI[T], v *viper.Viper, logger log.Logger) error {
-	cfg := s.Config().(*Config)
-	if v != nil {
-		if err := serverv2.UnmarshalSubConfig(v, s.Name(), &cfg); err != nil {
+func (s *Server[T]) Init(appI serverv2.AppI[T], cfg map[string]any, logger log.Logger) error {
+	serverCfg := s.Config().(*Config)
+	if len(cfg) > 0 {
+		if err := serverv2.UnmarshalSubConfig(cfg, s.Name(), &serverCfg); err != nil {
 			return fmt.Errorf("failed to unmarshal config: %w", err)
 		}
 	}
@@ -58,8 +57,8 @@ func (s *Server[T]) Init(appI serverv2.AppI[T], v *viper.Viper, logger log.Logge
 
 	grpcSrv := grpc.NewServer(
 		grpc.ForceServerCodec(newProtoCodec(appI.InterfaceRegistry()).GRPCCodec()),
-		grpc.MaxSendMsgSize(cfg.MaxSendMsgSize),
-		grpc.MaxRecvMsgSize(cfg.MaxRecvMsgSize),
+		grpc.MaxSendMsgSize(serverCfg.MaxSendMsgSize),
+		grpc.MaxRecvMsgSize(serverCfg.MaxRecvMsgSize),
 		grpc.UnknownServiceHandler(
 			makeUnknownServiceHandler(methodsMap, appI.GetAppManager()),
 		),
@@ -69,7 +68,7 @@ func (s *Server[T]) Init(appI serverv2.AppI[T], v *viper.Viper, logger log.Logge
 	gogoreflection.Register(grpcSrv, slices.Collect(maps.Keys(methodsMap)), logger.With("sub-module", "grpc-reflection"))
 
 	s.grpcSrv = grpcSrv
-	s.config = cfg
+	s.config = serverCfg
 	s.logger = logger.With(log.ModuleKey, s.Name())
 
 	return nil
diff --git a/server/v2/api/grpcgateway/server.go b/server/v2/api/grpcgateway/server.go
index 028027a83a07..05a6bf1aa829 100644
--- a/server/v2/api/grpcgateway/server.go
+++ b/server/v2/api/grpcgateway/server.go
@@ -10,7 +10,6 @@ import (
 	"github.com/cosmos/gogoproto/jsonpb"
 	"github.com/gorilla/mux"
 	"github.com/grpc-ecosystem/grpc-gateway/runtime"
-	"github.com/spf13/viper"
 	"google.golang.org/grpc"
 
 	"cosmossdk.io/core/transaction"
@@ -83,10 +82,10 @@ func (s *GRPCGatewayServer[T]) Config() any {
 	return s.config
 }
 
-func (s *GRPCGatewayServer[T]) Init(appI serverv2.AppI[transaction.Tx], v *viper.Viper, logger log.Logger) error {
-	cfg := s.Config().(*Config)
-	if v != nil {
-		if err := serverv2.UnmarshalSubConfig(v, s.Name(), &cfg); err != nil {
+func (s *GRPCGatewayServer[T]) Init(appI serverv2.AppI[transaction.Tx], cfg map[string]any, logger log.Logger) error {
+	serverCfg := s.Config().(*Config)
+	if len(cfg) > 0 {
+		if err := serverv2.UnmarshalSubConfig(cfg, s.Name(), &serverCfg); err != nil {
 			return fmt.Errorf("failed to unmarshal config: %w", err)
 		}
 	}
@@ -95,7 +94,7 @@ func (s *GRPCGatewayServer[T]) Init(appI serverv2.AppI[transaction.Tx], v *viper
 	// appI.RegisterGRPCGatewayRoutes(s.GRPCGatewayRouter, s.GRPCSrv)
 
 	s.logger = logger
-	s.config = cfg
+	s.config = serverCfg
 
 	return nil
 }
diff --git a/server/v2/cometbft/config.go b/server/v2/cometbft/config.go
index 56860a78ddaf..81f3aeb33354 100644
--- a/server/v2/cometbft/config.go
+++ b/server/v2/cometbft/config.go
@@ -2,9 +2,6 @@ package cometbft
 
 import (
 	cmtcfg "github.com/cometbft/cometbft/config"
-	"github.com/spf13/viper"
-
-	serverv2 "cosmossdk.io/server/v2"
 )
 
 // Config is the configuration for the CometBFT application
@@ -53,14 +50,3 @@ func OverwriteDefaultAppTomlConfig(newCfg *AppTomlConfig) CfgOption {
 		cfg.AppTomlConfig = newCfg
 	}
 }
-
-func getConfigTomlFromViper(v *viper.Viper) *cmtcfg.Config {
-	rootDir := v.GetString(serverv2.FlagHome)
-
-	conf := cmtcfg.DefaultConfig()
-	if err := v.Unmarshal(conf); err != nil {
-		return cmtcfg.DefaultConfig().SetRoot(rootDir)
-	}
-
-	return conf.SetRoot(rootDir)
-}
diff --git a/server/v2/cometbft/server.go b/server/v2/cometbft/server.go
index 14e7cdb7bcaa..4dfb4e720a18 100644
--- a/server/v2/cometbft/server.go
+++ b/server/v2/cometbft/server.go
@@ -19,7 +19,6 @@ import (
 	"github.com/cometbft/cometbft/proxy"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
-	"github.com/spf13/viper"
 
 	"cosmossdk.io/core/transaction"
 	"cosmossdk.io/log"
@@ -58,23 +57,30 @@ func New[T transaction.Tx](txCodec transaction.Codec[T], serverOptions ServerOpt
 	}
 }
 
-func (s *CometBFTServer[T]) Init(appI serverv2.AppI[T], v *viper.Viper, logger log.Logger) error {
+func (s *CometBFTServer[T]) Init(appI serverv2.AppI[T], cfg map[string]any, logger log.Logger) error {
+	home, _ := cfg[serverv2.FlagHome].(string)
+
 	// get configs (app.toml + config.toml) from viper
 	appTomlConfig := s.Config().(*AppTomlConfig)
-	if v != nil {
-		if err := serverv2.UnmarshalSubConfig(v, s.Name(), &appTomlConfig); err != nil {
+	configTomlConfig := cmtcfg.DefaultConfig().SetRoot(home)
+	if len(cfg) > 0 {
+		if err := serverv2.UnmarshalSubConfig(cfg, s.Name(), &appTomlConfig); err != nil {
+			return fmt.Errorf("failed to unmarshal config: %w", err)
+		}
+
+		if err := serverv2.UnmarshalSubConfig(cfg, "", &configTomlConfig); err != nil {
 			return fmt.Errorf("failed to unmarshal config: %w", err)
 		}
 	}
 	s.config = Config{
-		ConfigTomlConfig: getConfigTomlFromViper(v),
+		ConfigTomlConfig: configTomlConfig,
 		AppTomlConfig:    appTomlConfig,
 	}
 
-	chainID := v.GetString(FlagChainID)
+	chainID, _ := cfg[FlagChainID].(string)
 	if chainID == "" {
 		// fallback to genesis chain-id
-		reader, err := os.Open(filepath.Join(v.GetString(serverv2.FlagHome), "config", "genesis.json"))
+		reader, err := os.Open(filepath.Join(home, "config", "genesis.json"))
 		if err != nil {
 			panic(err)
 		}
diff --git a/server/v2/commands.go b/server/v2/commands.go
index 101a23d3983e..8651074f406f 100644
--- a/server/v2/commands.go
+++ b/server/v2/commands.go
@@ -112,7 +112,7 @@ func createStartCommand[T transaction.Tx](
 				return err
 			}
 
-			if err := server.Init(newApp(l, v), v, l); err != nil {
+			if err := server.Init(newApp(l, v), v.AllSettings(), l); err != nil {
 				return err
 			}
 
diff --git a/server/v2/config.go b/server/v2/config.go
index b5c525fdf682..c7df142c3805 100644
--- a/server/v2/config.go
+++ b/server/v2/config.go
@@ -39,12 +39,10 @@ func ReadConfig(configPath string) (*viper.Viper, error) {
 	return v, nil
 }
 
-// UnmarshalSubConfig unmarshals the given subconfig from the viper instance.
-// It unmarshals the config, env, flags into the target struct.
-// Use this instead of viper.Sub because viper does not unmarshal flags.
-func UnmarshalSubConfig(v *viper.Viper, subName string, target any) error {
+// UnmarshalSubConfig unmarshals the given sub config from the main config (given as a map) into the target.
+func UnmarshalSubConfig(cfg map[string]any, subName string, target any) error {
 	var sub any
-	for k, val := range v.AllSettings() {
+	for k, val := range cfg {
 		if k == subName {
 			sub = val
 			break
diff --git a/server/v2/config_test.go b/server/v2/config_test.go
index a24cd4cf3d2e..6577b81192fb 100644
--- a/server/v2/config_test.go
+++ b/server/v2/config_test.go
@@ -31,16 +31,17 @@ func TestUnmarshalSubConfig(t *testing.T) {
 
 	v, err := serverv2.ReadConfig(configPath)
 	require.NoError(t, err)
+	cfg := v.AllSettings()
 
 	grpcConfig := grpc.DefaultConfig()
-	err = serverv2.UnmarshalSubConfig(v, "grpc", &grpcConfig)
+	err = serverv2.UnmarshalSubConfig(cfg, "grpc", &grpcConfig)
 	require.NoError(t, err)
 
 	require.True(t, grpc.DefaultConfig().Enable)
 	require.False(t, grpcConfig.Enable)
 
 	storeConfig := store.Config{}
-	err = serverv2.UnmarshalSubConfig(v, "store", &storeConfig)
+	err = serverv2.UnmarshalSubConfig(cfg, "store", &storeConfig)
 	require.NoError(t, err)
 	require.Equal(t, *store.DefaultConfig(), storeConfig)
 }
diff --git a/server/v2/server.go b/server/v2/server.go
index 08ae9a6a06fa..d1062618ab60 100644
--- a/server/v2/server.go
+++ b/server/v2/server.go
@@ -10,7 +10,6 @@ import (
 	"github.com/pelletier/go-toml/v2"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
-	"github.com/spf13/viper"
 	"golang.org/x/sync/errgroup"
 
 	"cosmossdk.io/core/transaction"
@@ -23,7 +22,7 @@ type ServerComponent[T transaction.Tx] interface {
 
 	Start(context.Context) error
 	Stop(context.Context) error
-	Init(AppI[T], *viper.Viper, log.Logger) error
+	Init(AppI[T], map[string]any, log.Logger) error
 }
 
 // HasStartFlags is a server module that has start flags.
@@ -189,10 +188,10 @@ func (s *Server[T]) StartCmdFlags() *pflag.FlagSet {
 
 // Init initializes all server components with the provided application, configuration, and logger.
 // It returns an error if any component fails to initialize.
-func (s *Server[T]) Init(appI AppI[T], v *viper.Viper, logger log.Logger) error {
-	cfg := s.config
-	if v != nil {
-		if err := UnmarshalSubConfig(v, s.Name(), &cfg); err != nil {
+func (s *Server[T]) Init(appI AppI[T], cfg map[string]any, logger log.Logger) error {
+	serverCfg := s.config
+	if len(cfg) > 0 {
+		if err := UnmarshalSubConfig(cfg, s.Name(), &serverCfg); err != nil {
 			return fmt.Errorf("failed to unmarshal config: %w", err)
 		}
 	}
@@ -200,14 +199,14 @@ func (s *Server[T]) Init(appI AppI[T], v *viper.Viper, logger log.Logger) error
 	var components []ServerComponent[T]
 	for _, mod := range s.components {
 		mod := mod
-		if err := mod.Init(appI, v, logger); err != nil {
+		if err := mod.Init(appI, cfg, logger); err != nil {
 			return err
 		}
 
 		components = append(components, mod)
 	}
 
-	s.config = cfg
+	s.config = serverCfg
 	s.components = components
 	return nil
 }
diff --git a/server/v2/server_mock_test.go b/server/v2/server_mock_test.go
index ae238d66a57a..8b590ba2d32f 100644
--- a/server/v2/server_mock_test.go
+++ b/server/v2/server_mock_test.go
@@ -5,8 +5,6 @@ import (
 	"fmt"
 	"math/rand"
 
-	"github.com/spf13/viper"
-
 	"cosmossdk.io/core/transaction"
 	"cosmossdk.io/log"
 	serverv2 "cosmossdk.io/server/v2"
@@ -33,7 +31,7 @@ func (s *mockServer) Name() string {
 	return s.name
 }
 
-func (s *mockServer) Init(appI serverv2.AppI[transaction.Tx], v *viper.Viper, logger log.Logger) error {
+func (s *mockServer) Init(appI serverv2.AppI[transaction.Tx], cfg map[string]any, logger log.Logger) error {
 	return nil
 }
 
diff --git a/server/v2/server_test.go b/server/v2/server_test.go
index 98b1def5ab9f..e84bcd598890 100644
--- a/server/v2/server_test.go
+++ b/server/v2/server_test.go
@@ -56,14 +56,15 @@ func TestServer(t *testing.T) {
 	if err != nil {
 		v = viper.New()
 	}
+	cfg := v.AllSettings()
 
 	logger := log.NewLogger(os.Stdout)
 	grpcServer := grpc.New[transaction.Tx]()
-	err = grpcServer.Init(&mockApp[transaction.Tx]{}, v, logger)
+	err = grpcServer.Init(&mockApp[transaction.Tx]{}, cfg, logger)
 	require.NoError(t, err)
 
 	storeServer := store.New[transaction.Tx](nil /* nil appCreator as not using CLI commands */)
-	err = storeServer.Init(&mockApp[transaction.Tx]{}, v, logger)
+	err = storeServer.Init(&mockApp[transaction.Tx]{}, cfg, logger)
 	require.NoError(t, err)
 
 	mockServer := &mockServer{name: "mock-server-1", ch: make(chan string, 100)}
diff --git a/server/v2/store/server.go b/server/v2/store/server.go
index 1177c6a0c414..e16a09137a4b 100644
--- a/server/v2/store/server.go
+++ b/server/v2/store/server.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 
 	"github.com/spf13/cobra"
-	"github.com/spf13/viper"
 
 	"cosmossdk.io/core/transaction"
 	"cosmossdk.io/log"
@@ -24,14 +23,14 @@ func New[T transaction.Tx](appCreator serverv2.AppCreator[T]) *StoreComponent[T]
 	return &StoreComponent[T]{appCreator: appCreator}
 }
 
-func (s *StoreComponent[T]) Init(appI serverv2.AppI[T], v *viper.Viper, logger log.Logger) error {
-	cfg := DefaultConfig()
-	if v != nil {
-		if err := serverv2.UnmarshalSubConfig(v, s.Name(), &cfg); err != nil {
+func (s *StoreComponent[T]) Init(appI serverv2.AppI[T], cfg map[string]any, logger log.Logger) error {
+	serverCfg := DefaultConfig()
+	if len(cfg) > 0 {
+		if err := serverv2.UnmarshalSubConfig(cfg, s.Name(), &serverCfg); err != nil {
 			return fmt.Errorf("failed to unmarshal config: %w", err)
 		}
 	}
-	s.config = cfg
+	s.config = serverCfg
 	return nil
 }
 

From ad8ead558ecf9b278bf8054b5d727723ba7dab48 Mon Sep 17 00:00:00 2001
From: Julien Robert <julien@rbrt.fr>
Date: Wed, 11 Sep 2024 21:13:17 +0200
Subject: [PATCH 2/3] updates

---
 server/v2/cometbft/go.mod | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/v2/cometbft/go.mod b/server/v2/cometbft/go.mod
index 3709cd1f4561..57b947da1fe3 100644
--- a/server/v2/cometbft/go.mod
+++ b/server/v2/cometbft/go.mod
@@ -37,7 +37,6 @@ require (
 	github.com/grpc-ecosystem/grpc-gateway v1.16.0
 	github.com/spf13/cobra v1.8.1
 	github.com/spf13/pflag v1.0.5
-	github.com/spf13/viper v1.19.0
 	github.com/stretchr/testify v1.9.0
 	google.golang.org/genproto/googleapis/api v0.0.0-20240604185151-ef581f913117
 	google.golang.org/grpc v1.66.1
@@ -150,6 +149,7 @@ require (
 	github.com/sourcegraph/conc v0.3.0 // indirect
 	github.com/spf13/afero v1.11.0 // indirect
 	github.com/spf13/cast v1.7.0 // indirect
+	github.com/spf13/viper v1.19.0 // indirect
 	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/supranational/blst v0.3.13 // indirect
 	github.com/syndtr/goleveldb v1.0.1-0.20220721030215-126854af5e6d // indirect

From 2cca86d5e5e7bee8f884cb6c8792574dc66df354 Mon Sep 17 00:00:00 2001
From: Julien Robert <julien@rbrt.fr>
Date: Wed, 11 Sep 2024 21:19:40 +0200
Subject: [PATCH 3/3] updates

---
 server/v2/cometbft/server.go |  1 +
 server/v2/config.go          | 15 ++++++++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/server/v2/cometbft/server.go b/server/v2/cometbft/server.go
index 4dfb4e720a18..26cd99ff97cd 100644
--- a/server/v2/cometbft/server.go
+++ b/server/v2/cometbft/server.go
@@ -72,6 +72,7 @@ func (s *CometBFTServer[T]) Init(appI serverv2.AppI[T], cfg map[string]any, logg
 			return fmt.Errorf("failed to unmarshal config: %w", err)
 		}
 	}
+
 	s.config = Config{
 		ConfigTomlConfig: configTomlConfig,
 		AppTomlConfig:    appTomlConfig,
diff --git a/server/v2/config.go b/server/v2/config.go
index c7df142c3805..0670bc374a24 100644
--- a/server/v2/config.go
+++ b/server/v2/config.go
@@ -39,14 +39,19 @@ func ReadConfig(configPath string) (*viper.Viper, error) {
 	return v, nil
 }
 
-// UnmarshalSubConfig unmarshals the given sub config from the main config (given as a map) into the target.
+// UnmarshalSubConfig unmarshals the given (sub) config from the main config (given as a map) into the target.
+// If subName is empty, the main config is unmarshaled into the target.
 func UnmarshalSubConfig(cfg map[string]any, subName string, target any) error {
 	var sub any
-	for k, val := range cfg {
-		if k == subName {
-			sub = val
-			break
+	if subName != "" {
+		for k, val := range cfg {
+			if k == subName {
+				sub = val
+				break
+			}
 		}
+	} else {
+		sub = cfg
 	}
 
 	// Create a new decoder with custom decoding options