Merge PR #2328: Support min fees-based anti spam strategy

server/config/config.go

@@ -1,5 +1,41 @@
 package config
 
+import (
+	"fmt"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+const (
+	defaultMinimumFees = ""
+)
+
+// BaseConfig defines the server's basic configuration
+type BaseConfig struct {
+	// Tx minimum fee
+	MinFees string `mapstructure:"minimum_fees"`
+}
+
+// Config defines the server's top level configuration
+type Config struct {
+	BaseConfig `mapstructure:",squash"`
+}
+
+// SetMinimumFee sets the minimum fee.
+func (c *Config) SetMinimumFees(fees sdk.Coins) { c.MinFees = fees.String() }
+
+// SetMinimumFee sets the minimum fee.
+func (c *Config) MinimumFees() sdk.Coins {
+	fees, err := sdk.ParseCoins(c.MinFees)
+	if err != nil {
+		panic(fmt.Sprintf("invalid minimum fees: %v", err))
+	}
+	return fees
+}
+
+// DefaultConfig returns server's default configuration.
+func DefaultConfig() *Config { return &Config{BaseConfig{MinFees: defaultMinimumFees}} }
+
 //_____________________________________________________________________
 
 // Configuration structure for command functions that share configuration.

server/config/config_test.go

@@ -0,0 +1,19 @@
+package config
+
+import (
+	"testing"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDefaultConfig(t *testing.T) {
+	cfg := DefaultConfig()
+	require.True(t, cfg.MinimumFees().IsZero())
+}
+
+func TestSetMinimumFees(t *testing.T) {
+	cfg := DefaultConfig()
+	cfg.SetMinimumFees(sdk.Coins{sdk.NewCoin("foo", sdk.NewInt(100))})
+	require.Equal(t, "100foo", cfg.MinFees)
+}

server/config/toml.go

@@ -0,0 +1,46 @@
+package config
+
+import (
+	"bytes"
+	"text/template"
+
+	"github.com/spf13/viper"
+	cmn "github.com/tendermint/tendermint/libs/common"
+)
+
+const defaultConfigTemplate = `# This is a TOML config file.
+# For more information, see https://github.com/toml-lang/toml
+
+##### main base config options #####
+
+# Validators reject any tx from the mempool with less than the minimum fee per gas.
+minimum_fees = "{{ .BaseConfig.MinFees }}"
+`
+
+var configTemplate *template.Template
+
+func init() {
+	var err error
+	tmpl := template.New("cosmosConfigFileTemplate")
+	if configTemplate, err = tmpl.Parse(defaultConfigTemplate); err != nil {
+		panic(err)
+	}
+}
+
+// ParseConfig retrieves the default environment configuration for Cosmos.
+func ParseConfig() (*Config, error) {
+	conf := DefaultConfig()
+	err := viper.Unmarshal(conf)
+	return conf, err
+}
+
+// WriteConfigFile renders config using the template and writes it to configFilePath.
+func WriteConfigFile(configFilePath string, config *Config) {
+	var buffer bytes.Buffer
+
+	if err := configTemplate.Execute(&buffer, config); err != nil {
+		panic(err)
+	}
+
+	cmn.MustWriteFile(configFilePath, buffer.Bytes(), 0644)
+}

server/start.go

@@ -19,6 +19,7 @@ const (
 	flagAddress        = "address"
 	flagTraceStore     = "trace-store"
 	flagPruning        = "pruning"
+	flagMinimumFees    = "minimum_fees"
 )
 
 // StartCmd runs the service passed in, either stand-alone or in-process with
@@ -45,6 +46,7 @@ func StartCmd(ctx *Context, appCreator AppCreator) *cobra.Command {
 	cmd.Flags().String(flagAddress, "tcp://0.0.0.0:26658", "Listen address")
 	cmd.Flags().String(flagTraceStore, "", "Enable KVStore tracing to an output file")
 	cmd.Flags().String(flagPruning, "syncable", "Pruning strategy: syncable, nothing, everything")
+	cmd.Flags().String(flagMinimumFees, "", "Minimum fees validator will accept for transactions")
 
 	// add support for all Tendermint-specific command line options
 	tcmd.AddNodeFlags(cmd)

server/util.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/server/config"
 	"github.com/cosmos/cosmos-sdk/version"
 	tcmd "github.com/tendermint/tendermint/cmd/tendermint/commands"
 	cfg "github.com/tendermint/tendermint/config"
@@ -97,6 +98,20 @@ func interceptLoadConfig() (conf *cfg.Config, err error) {
 	if conf == nil {
 		conf, err = tcmd.ParseConfig()
 	}
+
+	cosmosConfigFilePath := filepath.Join(rootDir, "config/gaiad.toml")
+	viper.SetConfigName("cosmos")
+	_ = viper.MergeInConfig()
+	var cosmosConf *config.Config
+	if _, err := os.Stat(cosmosConfigFilePath); os.IsNotExist(err) {
+		cosmosConf, _ := config.ParseConfig()
+		config.WriteConfigFile(cosmosConfigFilePath, cosmosConf)
+	}
+
+	if cosmosConf == nil {
+		_, err = config.ParseConfig()
+	}
+
 	return
 }