Add serve command bootstrap

cmd/root/root.go

@@ -3,8 +3,13 @@ package root
 import (
 	"context"
 	"flag"
+	"fmt"
+	"os"
 
+	"github.com/gnolang/faucet"
 	"github.com/gnolang/faucet/config"
+	"github.com/gnolang/faucet/waiter"
+	"github.com/pelletier/go-toml"
 	"github.com/peterbourgon/ff/v3"
 	"github.com/peterbourgon/ff/v3/ffcli"
 	"github.com/peterbourgon/ff/v3/fftoml"
@@ -16,7 +21,7 @@ const (
 )
 
 // faucetCfg wraps the faucet
-// startup command configuration
+// root command configuration
 type faucetCfg struct {
 	config.Config
 
@@ -27,12 +32,12 @@ type faucetCfg struct {
 func New() *ffcli.Command {
 	cfg := &faucetCfg{}
 
-	fs := flag.NewFlagSet("start", flag.ExitOnError)
+	fs := flag.NewFlagSet("serve", flag.ExitOnError)
 	registerFlags(cfg, fs)
 
 	return &ffcli.Command{
-		Name:       "start",
-		ShortUsage: "start [flags]",
+		Name:       "serve",
+		ShortUsage: "serve [flags]",
 		LongHelp:   "Starts the Gno faucet service",
 		FlagSet:    fs,
 		Exec:       cfg.exec,
@@ -42,6 +47,7 @@ func New() *ffcli.Command {
 			ff.WithEnvVarPrefix(envPrefix),
 
 			// Allow using TOML config files
+			ff.WithAllowMissingConfigFile(true),
 			ff.WithConfigFileFlag(configFlagName),
 			ff.WithConfigFileParser(fftoml.Parser),
 		},
@@ -61,35 +67,42 @@ func registerFlags(cfg *faucetCfg, fs *flag.FlagSet) {
 	fs.StringVar(
 		&cfg.ListenAddress,
 		"listen-address",
-		"0.0.0.0:8545",
+		config.DefaultListenAddress,
 		"the IP:PORT URL for the faucet server",
 	)
 
 	fs.StringVar(
 		&cfg.Remote,
 		"remote",
-		"http://127.0.0.1:26657",
+		config.DefaultRemote,
 		"the JSON-RPC URL of the Gno chain",
 	)
 
 	fs.StringVar(
 		&cfg.ChainID,
-		"chain-id",
+		config.DefaultChainID,
 		"dev",
 		"the chain ID associated with the remote Gno chain",
 	)
 
+	fs.StringVar(
+		&cfg.SendAmount,
+		"send-amount",
+		config.DefaultSendAmount,
+		"the static send amount (native currency)",
+	)
+
 	fs.StringVar(
 		&cfg.GasFee,
 		"gas-fee",
-		"1000000ugnot",
+		config.DefaultGasFee,
 		"the static gas fee for the transaction",
 	)
 
 	fs.StringVar(
 		&cfg.GasWanted,
 		"gas-wanted",
-		"100000",
+		config.DefaultGasWanted,
 		"the static gas wanted for the transaction",
 	)
 
@@ -101,9 +114,49 @@ func registerFlags(cfg *faucetCfg, fs *flag.FlagSet) {
 	)
 }
 
-// exec executes the faucet start command
+// exec executes the faucet root command
 func (c *faucetCfg) exec(context.Context, []string) error {
-	// TODO
+	// Read the CORS configuration, if any
+	if c.corsConfigPath != "" {
+		corsConfig, err := readCORSConfig(c.corsConfigPath)
+		if err != nil {
+			return fmt.Errorf("unable to read CORS config, %w", err)
+		}
+
+		c.CORSConfig = corsConfig
+	}
+
+	// Create a new faucet
+	f, err := faucet.NewFaucet()
+	if err != nil {
+		return fmt.Errorf("unable to create faucet, %w", err)
+	}
+
+	// Create a new waiter
+	w := waiter.New()
+
+	// Add the faucet service
+	w.Add(f.Serve)
+
+	// Wait for the faucet to exit
+	return w.Wait()
+}
+
+// readCORSConfig reads the CORS configuration
+// from the specified path
+func readCORSConfig(path string) (*config.CORS, error) {
+	// Read the config file
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	// Parse it
+	var corsConfig config.CORS
+	err = toml.Unmarshal(content, &corsConfig)
+	if err != nil {
+		return nil, err
+	}
 
-	return nil
+	return &corsConfig, nil
 }

config/config.go

@@ -1,5 +1,26 @@
 package config
 
+import (
+	"errors"
+	"regexp"
+)
+
+const (
+	DefaultListenAddress = "0.0.0.0:8545"
+	DefaultRemote        = "http://127.0.0.1:26657"
+	DefaultChainID       = "dev"
+	DefaultSendAmount    = "1000000ugnot"
+	DefaultGasFee        = "1000000ugnot"
+	DefaultGasWanted     = "100000"
+)
+
+var (
+	listenAddressRegex = regexp.MustCompile(`^\d{1,3}(\.\d{1,3}){3}:\d+$`)
+	remoteRegex        = regexp.MustCompile(`^https?:\/\/(?:w{1,3}\.)?[^\s.]+(?:\.[a-z]+)*(?::\d+)(?![^<]*(?:<\/\w+>|\/?>))$`)
+	amountRegex        = regexp.MustCompile(`^\d+ugnot$`)
+	numberRegex        = regexp.MustCompile(`^\d+$`)
+)
+
 // Config defines the base-level Faucet configuration
 type Config struct {
 	// The address at which the faucet will be served.
@@ -12,14 +33,66 @@ type Config struct {
 	// The chain ID associated with the remote Gno chain
 	ChainID string `toml:"chain_id"`
 
+	// The static send amount (native currency).
+	// Format should be: <AMOUNT>ugnot
+	SendAmount string `toml:"send_amount"`
+
 	// The static gas fee for the transaction.
 	// Format should be: <AMOUNT>ugnot
 	GasFee string `toml:"gas_fee"`
 
 	// The static gas wanted for the transaction.
-	// Format should be: <AMOUNT>ugnot
+	// Format should be: <AMOUNT>
 	GasWanted string `toml:"gas_wanted"`
 
 	// The associated CORS config, if any
 	CORSConfig *CORS `toml:"cors_config"`
 }
+
+// DefaultConfig returns the default faucet configuration
+func DefaultConfig() *Config {
+	return &Config{
+		ListenAddress: DefaultListenAddress,
+		Remote:        DefaultRemote,
+		ChainID:       DefaultChainID,
+		SendAmount:    DefaultSendAmount,
+		GasFee:        DefaultGasFee,
+		GasWanted:     DefaultGasWanted,
+		CORSConfig:    DefaultCORSConfig(),
+	}
+}
+
+// ValidateConfig validates the faucet configuration
+func ValidateConfig(config *Config) error {
+	// validate the listen address
+	if !listenAddressRegex.Match([]byte(config.ListenAddress)) {
+		return errors.New("invalid listen address")
+	}
+
+	// validate the remote address
+	if !remoteRegex.Match([]byte(config.Remote)) {
+		return errors.New("invalid remote address")
+	}
+
+	// validate the chain ID
+	if config.ChainID == "" {
+		return errors.New("invalid chain ID")
+	}
+
+	// validate the send amount
+	if !amountRegex.Match([]byte(config.SendAmount)) {
+		return errors.New("invalid send amount")
+	}
+
+	// validate the gas fee
+	if !amountRegex.Match([]byte(config.GasFee)) {
+		return errors.New("invalid gas fee")
+	}
+
+	// validate the gas wanted
+	if !numberRegex.Match([]byte(config.GasWanted)) {
+		return errors.New("invalid gas wanted")
+	}
+
+	return nil
+}

config/cors.go

@@ -1,5 +1,9 @@
 package config
 
+import (
+	"net/http"
+)
+
 // CORS defines the Faucet CORS configuration
 type CORS struct {
 	// A list of origins a cross-domain request can be executed from.
@@ -14,3 +18,12 @@ type CORS struct {
 	// A list of methods the client is allowed to use with cross-domain requests
 	AllowedMethods []string `toml:"cors_allowed_methods"`
 }
+
+// DefaultCORSConfig returns the default CORS configuration
+func DefaultCORSConfig() *CORS {
+	return &CORS{
+		AllowedOrigins: []string{"*"},
+		AllowedMethods: []string{http.MethodHead, http.MethodGet, http.MethodPost, http.MethodOptions},
+		AllowedHeaders: []string{"Origin", "Accept", "Content-Type", "X-Requested-With", "X-Server-Time"},
+	}
+}

faucet.go

@@ -9,11 +9,11 @@ import (
 
 	"github.com/gnolang/faucet/config"
 	"github.com/go-chi/chi/v5"
+	"github.com/rs/cors"
 	"golang.org/x/sync/errgroup"
 )
 
-// Faucet is a standard Gno
-// native currency faucet
+// Faucet is a standard Gno faucet
 type Faucet struct {
 	estimator Estimator // gas pricing estimations
 	logger    Logger    // log feedback
@@ -22,15 +22,17 @@ type Faucet struct {
 
 	config      *config.Config // faucet configuration
 	middlewares []Middleware   // request middlewares
+	handlers    []Handler      // request handlers
 }
 
 // NewFaucet creates a new instance of the Gno faucet server
-func NewFaucet(opts ...Option) *Faucet {
+func NewFaucet(opts ...Option) (*Faucet, error) {
 	f := &Faucet{
 		estimator:   nil, // TODO static estimator
 		logger:      nil, // TODO nil logger
-		config:      nil, // TODO default config
-		middlewares: nil, // TODO no middlewares
+		config:      config.DefaultConfig(),
+		middlewares: nil,
+		handlers:    nil, // TODO single default handler
 
 		mux: chi.NewMux(),
 	}
@@ -40,7 +42,33 @@ func NewFaucet(opts ...Option) *Faucet {
 		opt(f)
 	}
 
-	return f
+	// Validate the configuration
+	if err := config.ValidateConfig(f.config); err != nil {
+		return nil, fmt.Errorf("invalid configuration, %w", err)
+	}
+
+	// Set up the CORS middleware
+	if f.config.CORSConfig != nil {
+		corsMiddleware := cors.New(cors.Options{
+			AllowedOrigins: f.config.CORSConfig.AllowedOrigins,
+			AllowedMethods: f.config.CORSConfig.AllowedMethods,
+			AllowedHeaders: f.config.CORSConfig.AllowedHeaders,
+		})
+
+		f.mux.Use(corsMiddleware.Handler)
+	}
+
+	// Set up additional middlewares
+	for _, middleware := range f.middlewares {
+		f.mux.Use(middleware)
+	}
+
+	// Set up the request handlers
+	for _, handler := range f.handlers {
+		f.mux.HandleFunc(handler.Pattern, handler.HandlerFunc)
+	}
+
+	return f, nil
 }
 
 // Serve serves the Gno faucet [BLOCKING]

go.mod

@@ -5,6 +5,7 @@ go 1.21
 require (
 	github.com/go-chi/chi/v5 v5.0.10
 	github.com/peterbourgon/ff/v3 v3.4.0
+	github.com/rs/cors v1.10.0
 	golang.org/x/sync v0.3.0
 )
 

go.sum

@@ -4,5 +4,7 @@ github.com/pelletier/go-toml v1.9.5 h1:4yBQzkHv+7BHq2PQUZF3Mx0IYxG7LsP222s7Agd3v
 github.com/pelletier/go-toml v1.9.5/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
 github.com/peterbourgon/ff/v3 v3.4.0 h1:QBvM/rizZM1cB0p0lGMdmR7HxZeI/ZrBWB4DqLkMUBc=
 github.com/peterbourgon/ff/v3 v3.4.0/go.mod h1:zjJVUhx+twciwfDl0zBcFzl4dW8axCRyXE/eKY9RztQ=
+github.com/rs/cors v1.10.0 h1:62NOS1h+r8p1mW6FM0FSB0exioXLhd/sh15KpjWBZ+8=
+github.com/rs/cors v1.10.0/go.mod h1:XyqrcTp5zjWr1wsJ8PIRZssZ8b/WMcMf71DJnit4EMU=
 golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
 golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=

handler.go

@@ -0,0 +1,7 @@
+package faucet
+
+// transferFunds transfers funds to the given address
+func (f *Faucet) transferFunds(address string) error {
+
+	return nil
+}

options.go

@@ -29,3 +29,9 @@ func WithMiddlewares(middlewares []Middleware) Option {
 		f.middlewares = middlewares
 	}
 }
+
+func WithHandlers(handlers []Handler) Option {
+	return func(f *Faucet) {
+		f.handlers = handlers
+	}
+}

types.go

@@ -13,3 +13,8 @@ type Logger interface {
 }
 
 type Middleware func(next http.Handler) http.Handler
+
+type Handler struct {
+	Pattern     string
+	HandlerFunc http.HandlerFunc
+}