cli: move network options to their own package

They will be reused.

cli/options/options.go

@@ -0,0 +1,30 @@
+/*
+Package options contains a set of common CLI options and helper functions to use them.
+*/
+package options
+
+import (
+	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
+	"github.com/urfave/cli"
+)
+
+// Network is a set of flags for choosing the network to operate on
+// (privnet/mainnet/testnet).
+var Network = []cli.Flag{
+	cli.BoolFlag{Name: "privnet, p"},
+	cli.BoolFlag{Name: "mainnet, m"},
+	cli.BoolFlag{Name: "testnet, t"},
+}
+
+// GetNetwork examines Context's flags and returns the appropriate network. It
+// defaults to PrivNet if no flags are given.
+func GetNetwork(ctx *cli.Context) netmode.Magic {
+	var net = netmode.PrivNet
+	if ctx.Bool("testnet") {
+		net = netmode.TestNet
+	}
+	if ctx.Bool("mainnet") {
+		net = netmode.MainNet
+	}
+	return net
+}

cli/server/server.go

@@ -6,8 +6,8 @@ import (
 	"os"
 	"os/signal"
 
+	"github.com/nspcc-dev/neo-go/cli/options"
 	"github.com/nspcc-dev/neo-go/pkg/config"
-	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
 	"github.com/nspcc-dev/neo-go/pkg/core"
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
@@ -25,11 +25,9 @@ import (
 func NewCommands() []cli.Command {
 	var cfgFlags = []cli.Flag{
 		cli.StringFlag{Name: "config-path"},
-		cli.BoolFlag{Name: "privnet, p"},
-		cli.BoolFlag{Name: "mainnet, m"},
-		cli.BoolFlag{Name: "testnet, t"},
 		cli.BoolFlag{Name: "debug, d"},
 	}
+	cfgFlags = append(cfgFlags, options.Network...)
 	var cfgWithCountFlags = make([]cli.Flag, len(cfgFlags))
 	copy(cfgWithCountFlags, cfgFlags)
 	cfgWithCountFlags = append(cfgWithCountFlags,
@@ -108,18 +106,11 @@ func newGraceContext() context.Context {
 // getConfigFromContext looks at path and mode flags in the given config and
 // returns appropriate config.
 func getConfigFromContext(ctx *cli.Context) (config.Config, error) {
-	var net = netmode.PrivNet
-	if ctx.Bool("testnet") {
-		net = netmode.TestNet
-	}
-	if ctx.Bool("mainnet") {
-		net = netmode.MainNet
-	}
 	configPath := "./config"
 	if argCp := ctx.String("config-path"); argCp != "" {
 		configPath = argCp
 	}
-	return config.Load(configPath, net)
+	return config.Load(configPath, options.GetNetwork(ctx))
 }
 
 // handleLoggingParams reads logging parameters.