Add base faucet logic

cmd/faucet/main.go

@@ -0,0 +1,17 @@
+package faucet
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/gnolang/faucet/cmd/root"
+)
+
+func main() {
+	if err := root.New().ParseAndRun(context.Background(), os.Args[1:]); err != nil {
+		_, _ = fmt.Fprintf(os.Stderr, "%v\n", err)
+
+		os.Exit(1)
+	}
+}

cmd/root/root.go

@@ -0,0 +1,109 @@
+package root
+
+import (
+	"context"
+	"flag"
+
+	"github.com/gnolang/faucet/config"
+	"github.com/peterbourgon/ff/v3"
+	"github.com/peterbourgon/ff/v3/ffcli"
+	"github.com/peterbourgon/ff/v3/fftoml"
+)
+
+const (
+	configFlagName = "config"
+	envPrefix      = "GNO_FAUCET"
+)
+
+// faucetCfg wraps the faucet
+// startup command configuration
+type faucetCfg struct {
+	config.Config
+
+	corsConfigPath string
+}
+
+// New creates the root faucet command
+func New() *ffcli.Command {
+	cfg := &faucetCfg{}
+
+	fs := flag.NewFlagSet("start", flag.ExitOnError)
+	registerFlags(cfg, fs)
+
+	return &ffcli.Command{
+		Name:       "start",
+		ShortUsage: "start [flags]",
+		LongHelp:   "Starts the Gno faucet service",
+		FlagSet:    fs,
+		Exec:       cfg.exec,
+		Options: []ff.Option{
+			// Allow using ENV variables
+			ff.WithEnvVars(),
+			ff.WithEnvVarPrefix(envPrefix),
+
+			// Allow using TOML config files
+			ff.WithConfigFileFlag(configFlagName),
+			ff.WithConfigFileParser(fftoml.Parser),
+		},
+	}
+}
+
+// registerFlags registers the faucet root command flags
+func registerFlags(cfg *faucetCfg, fs *flag.FlagSet) {
+	// Config flag
+	fs.String(
+		configFlagName,
+		"",
+		"the path to the configuration file [TOML]",
+	)
+
+	// Top level flags
+	fs.StringVar(
+		&cfg.ListenAddress,
+		"listen-address",
+		"0.0.0.0:8545",
+		"the IP:PORT URL for the faucet server",
+	)
+
+	fs.StringVar(
+		&cfg.Remote,
+		"remote",
+		"http://127.0.0.1:26657",
+		"the JSON-RPC URL of the Gno chain",
+	)
+
+	fs.StringVar(
+		&cfg.ChainID,
+		"chain-id",
+		"dev",
+		"the chain ID associated with the remote Gno chain",
+	)
+
+	fs.StringVar(
+		&cfg.GasFee,
+		"gas-fee",
+		"1000000ugnot",
+		"the static gas fee for the transaction",
+	)
+
+	fs.StringVar(
+		&cfg.GasWanted,
+		"gas-wanted",
+		"100000",
+		"the static gas wanted for the transaction",
+	)
+
+	fs.StringVar(
+		&cfg.corsConfigPath,
+		"cors-config",
+		"",
+		"the path to the CORS TOML configuration, if any",
+	)
+}
+
+// exec executes the faucet start command
+func (c *faucetCfg) exec(context.Context, []string) error {
+	// TODO
+
+	return nil
+}

config/config.go

@@ -0,0 +1,25 @@
+package config
+
+// Config defines the base-level Faucet configuration
+type Config struct {
+	// The address at which the faucet will be served.
+	// Format should be: <IP>:<PORT>
+	ListenAddress string `toml:"listen_address"`
+
+	// The JSON-RPC URL of the Gno chain
+	Remote string `toml:"remote"`
+
+	// The chain ID associated with the remote Gno chain
+	ChainID string `toml:"chain_id"`
+
+	// 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
+	GasWanted string `toml:"gas_wanted"`
+
+	// The associated CORS config, if any
+	CORSConfig *CORS `toml:"cors_config"`
+}

config/cors.go

@@ -0,0 +1,16 @@
+package config
+
+// CORS defines the Faucet CORS configuration
+type CORS struct {
+	// A list of origins a cross-domain request can be executed from.
+	// If the special '*' value is present in the list, all origins will be allowed.
+	// An origin may contain a wildcard (*) to replace 0 or more characters (i.e.: http://*.domain.com).
+	// Only one wildcard can be used per origin
+	AllowedOrigins []string `toml:"cors_allowed_origins"`
+
+	// A list of non-simple headers the client is allowed to use with cross-domain requests
+	AllowedHeaders []string `toml:"cors_allowed_headers"`
+
+	// A list of methods the client is allowed to use with cross-domain requests
+	AllowedMethods []string `toml:"cors_allowed_methods"`
+}

faucet.go

@@ -0,0 +1,84 @@
+package faucet
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/gnolang/faucet/config"
+	"github.com/go-chi/chi/v5"
+	"golang.org/x/sync/errgroup"
+)
+
+// Faucet is a standard Gno
+// native currency faucet
+type Faucet struct {
+	estimator Estimator // gas pricing estimations
+	logger    Logger    // log feedback
+
+	mux *chi.Mux // HTTP routing
+
+	config      *config.Config // faucet configuration
+	middlewares []Middleware   // request middlewares
+}
+
+// NewFaucet creates a new instance of the Gno faucet server
+func NewFaucet(opts ...Option) *Faucet {
+	f := &Faucet{
+		estimator:   nil, // TODO static estimator
+		logger:      nil, // TODO nil logger
+		config:      nil, // TODO default config
+		middlewares: nil, // TODO no middlewares
+
+		mux: chi.NewMux(),
+	}
+
+	// Apply the options
+	for _, opt := range opts {
+		opt(f)
+	}
+
+	return f
+}
+
+// Serve serves the Gno faucet [BLOCKING]
+func (f *Faucet) Serve(ctx context.Context) error {
+	faucet := &http.Server{
+		Addr:              f.config.ListenAddress,
+		Handler:           f.mux,
+		ReadHeaderTimeout: 60 * time.Second,
+	}
+
+	group, gCtx := errgroup.WithContext(ctx)
+
+	group.Go(func() error {
+		f.logger.Info(
+			fmt.Sprintf(
+				"faucet started at %s",
+				f.config.ListenAddress,
+			),
+		)
+		defer f.logger.Info("faucet shut down")
+
+		if err := faucet.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			return err
+		}
+
+		return nil
+	})
+
+	group.Go(func() error {
+		<-gCtx.Done()
+
+		f.logger.Info("faucet to be shutdown")
+
+		wsCtx, cancel := context.WithTimeout(context.Background(), time.Second*30)
+		defer cancel()
+
+		return faucet.Shutdown(wsCtx)
+	})
+
+	return group.Wait()
+}

go.mod

@@ -0,0 +1,11 @@
+module github.com/gnolang/faucet
+
+go 1.21
+
+require (
+	github.com/go-chi/chi/v5 v5.0.10
+	github.com/peterbourgon/ff/v3 v3.4.0
+	golang.org/x/sync v0.3.0
+)
+
+require github.com/pelletier/go-toml v1.9.5 // indirect

go.sum

@@ -0,0 +1,8 @@
+github.com/go-chi/chi/v5 v5.0.10 h1:rLz5avzKpjqxrYwXNfmjkrYYXOyLJd37pz53UFHC6vk=
+github.com/go-chi/chi/v5 v5.0.10/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
+github.com/pelletier/go-toml v1.9.5 h1:4yBQzkHv+7BHq2PQUZF3Mx0IYxG7LsP222s7Agd3ve8=
+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=
+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=

options.go

@@ -0,0 +1,31 @@
+package faucet
+
+import (
+	"github.com/gnolang/faucet/config"
+)
+
+type Option func(f *Faucet)
+
+func WithLogger(l Logger) Option {
+	return func(f *Faucet) {
+		f.logger = l
+	}
+}
+
+func WithEstimator(e Estimator) Option {
+	return func(f *Faucet) {
+		f.estimator = e
+	}
+}
+
+func WithConfig(c *config.Config) Option {
+	return func(f *Faucet) {
+		f.config = c
+	}
+}
+
+func WithMiddlewares(middlewares []Middleware) Option {
+	return func(f *Faucet) {
+		f.middlewares = middlewares
+	}
+}

types.go

@@ -0,0 +1,15 @@
+package faucet
+
+import "net/http"
+
+type Estimator interface {
+	// TODO define
+}
+
+type Logger interface {
+	Info(msg string, args ...interface{})
+	Debug(msg string, args ...interface{})
+	Error(msg string, args ...interface{})
+}
+
+type Middleware func(next http.Handler) http.Handler