Error cascade

cmd/cli/add.go

@@ -11,21 +11,29 @@
 // Add prompts for the required information and creates a new peer
 func Add(hostname string, privKey, pubKey bool, owner, description string, confirm bool) {
 	config, err := LoadConfigFile()
-	check(err, "failed to load configuration file")
+	if err != nil {
+		return fmt.Errorf("%w - failed to load configuration file", err)
+	}
 	server := GetServer(config)
 
 	var private, public string
 	if privKey {
 		private = MustPromptString("private key", true)
 	}
 	if pubKey {
 		public = MustPromptString("public key", true)
 	}
 	if owner == "" {
-		owner = MustPromptString("owner", true)
+		owner, err = PromptString("owner", true)
+		if err != nil {
+			return fmt.Errorf("%w - invalid input for owner", err)
+		}
 	}
 	if description == "" {
-		description = MustPromptString("Description", true)
+		description, err = PromptString("Description", true)
+		if err != nil {
+			return fmt.Errorf("%w - invalid input for Description", err)
+		}
 	}
 
 	// publicKey := MustPromptString("PublicKey (optional)", false)
@@ -37,22 +45,32 @@
 	fmt.Fprintln(os.Stderr)
 
 	peer, err := lib.NewPeer(server, private, public, owner, hostname, description)
-	check(err, "failed to get new peer")
+	if err != nil {
+		return fmt.Errorf("%w - failed to get new peer", err)
+	}
 
 	// TODO Some kind of recovery here would be nice, to avoid
 	// leaving things in a potential broken state
 
-	config.MustAddPeer(peer)
+	if err = config.AddPeer(peer); err != nil {
+		return fmt.Errorf("%w - failed to add new peer", err)
+	}
 
 	peerType := viper.GetString("output")
 
 	peerConfigBytes, err := lib.AsciiPeerConfig(peer, peerType, *server)
-	check(err, "failed to get peer configuration")
+	if err != nil {
+		return fmt.Errorf("%w - failed to get peer configuration", err)
+	}
 	os.Stdout.Write(peerConfigBytes.Bytes())
 
-	config.MustSave()
+	if err = config.Save(); err != nil {
+		return fmt.Errorf("%w - failed to save config file", err)
+	}
 
 	server = GetServer(config)
-	err = server.ConfigureDevice()
-	check(err, "failed to configure device")
+	if err = server.ConfigureDevice(); err != nil {
+		return fmt.Errorf("%w - failed to configure device", err)
+	}
+	return nil
 }

cmd/cli/config.go

@@ -106,12 +106,6 @@ func LoadConfigFile() (*DsnetConfig, error) {
 	return &conf, nil
 }
 
-func MustLoadConfigFile() *DsnetConfig {
-	config, err := LoadConfigFile()
-	check(err, "failed to load configuration file")
-	return config
-}
-
 // Save writes the configuration to disk
 func (conf *DsnetConfig) Save() error {
 	configFile := viper.GetString("config_file")
@@ -124,12 +118,6 @@ func (conf *DsnetConfig) Save() error {
 	return nil
 }
 
-// MustSave is like Save except it exits on error
-func (conf *DsnetConfig) MustSave() {
-	err := conf.Save()
-	check(err, "failed to save config file")
-}
-
 // AddPeer adds a provided peer to the Peers list in the conf
 func (conf *DsnetConfig) AddPeer(peer lib.Peer) error {
 	// TODO validate all PeerConfig (keys etc)
@@ -169,12 +157,6 @@ func (conf *DsnetConfig) AddPeer(peer lib.Peer) error {
 	return nil
 }
 
-// MustAddPeer is like AddPeer, except it exist on error
-func (conf *DsnetConfig) MustAddPeer(peer lib.Peer) {
-	err := conf.AddPeer(peer)
-	check(err)
-}
-
 // RemovePeer removes a peer from the peer list based on hostname
 func (conf *DsnetConfig) RemovePeer(hostname string) error {
 	peerIndex := -1
@@ -195,12 +177,6 @@ func (conf *DsnetConfig) RemovePeer(hostname string) error {
 	return nil
 }
 
-// MustRemovePeer is like RemovePeer, except it exits on error
-func (conf *DsnetConfig) MustRemovePeer(hostname string) {
-	err := conf.RemovePeer(hostname)
-	check(err)
-}
-
 func (conf DsnetConfig) GetWgPeerConfigs() []wgtypes.PeerConfig {
 	wgPeers := make([]wgtypes.PeerConfig, 0, len(conf.Peers))
 

cmd/cli/init.go

@@ -15,22 +15,31 @@ import (
 	"github.com/spf13/viper"
 )
 
-func Init() {
+func Init() error {
 	listenPort := viper.GetInt("listen_port")
 	configFile := viper.GetString("config_file")
 	interfaceName := viper.GetString("interface_name")
 
 	_, err := os.Stat(configFile)
 
 	if !os.IsNotExist(err) {
-		ExitFail("Refusing to overwrite existing %s", configFile)
+		return fmt.Errorf("%w - Refusing to overwrite existing %s", err, configFile)
 	}
 
 	privateKey, err := lib.GenerateJSONPrivateKey()
-	check(err, "failed to generate private key")
+	if err != nil {
+		return fmt.Errorf("%w - failed to generate private key", err)
+	}
 
 	externalIPV4, err := getExternalIP()
-	check(err)
+	if err != nil {
+		return err
+	}
+
+	externalIPV6, err := getExternalIP6()
+	if err != nil {
+		return err
+	}
 
 	conf := &DsnetConfig{
 		PrivateKey:          privateKey,
@@ -40,7 +49,7 @@ func Init() {
 		Peers:               []PeerConfig{},
 		Domain:              "dsnet",
 		ExternalIP:          externalIPV4,
-		ExternalIP6:         getExternalIP6(),
+		ExternalIP6:         externalIPV6,
 		InterfaceName:       interfaceName,
 		Networks:            []lib.JSONIPNet{},
 		PersistentKeepalive: 25,
@@ -49,21 +58,28 @@ func Init() {
 	server := GetServer(conf)
 
 	ipv4, err := server.AllocateIP()
-	check(err, "failed to allocate ipv4 address")
+	if err != nil {
+		return fmt.Errorf("%w - failed to allocate ipv4 address", err)
+	}
 
 	ipv6, err := server.AllocateIP6()
-	check(err, "failed to allocate ipv6 address")
+	if err != nil {
+		return fmt.Errorf("%w - failed to allocate ipv6 address", err)
+	}
 
 	conf.IP = ipv4
 	conf.IP6 = ipv6
 
 	if len(conf.ExternalIP) == 0 && len(conf.ExternalIP6) == 0 {
-		ExitFail("Could not determine any external IP, v4 or v6")
+		return fmt.Errorf("Could not determine any external IP, v4 or v6")
 	}
 
-	conf.MustSave()
+	if err := conf.Save(); err != nil {
+		return fmt.Errorf("%w - failed to save config file", err)
+	}
 
 	fmt.Printf("Config written to %s. Please check/edit.\n", configFile)
+	return nil
 }
 
 // get a random IPv4  /22 subnet on 10.0.0.0 (1023 hosts) (or /24?)
@@ -119,20 +135,24 @@ func getExternalIP() (net.IP, error) {
 		Timeout: 5 * time.Second,
 	}
 	resp, err := client.Get("https://ipv4.icanhazip.com/")
-	check(err)
+	if err != nil {
+		return nil, err
+	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode == http.StatusOK {
 		body, err := ioutil.ReadAll(resp.Body)
-		check(err)
+		if err != nil {
+			return nil, err
+		}
 		IP = net.ParseIP(strings.TrimSpace(string(body)))
 		return IP.To4(), nil
 	}
 
 	return nil, errors.New("failed to determine external ip")
 }
 
-func getExternalIP6() net.IP {
+func getExternalIP6() (net.IP, error) {
 	var IP net.IP
 	conn, err := net.Dial("udp", "2001:4860:4860::8888:53")
 	if err == nil {
@@ -143,7 +163,7 @@ func getExternalIP6() net.IP {
 
 		// check is not a ULA
 		if IP[0] != 0xfd && IP[0] != 0xfc {
-			return IP
+			return IP, nil
 		}
 	}
 
@@ -156,11 +176,13 @@ func getExternalIP6() net.IP {
 
 		if resp.StatusCode == http.StatusOK {
 			body, err := ioutil.ReadAll(resp.Body)
-			check(err)
+			if err != nil {
+				return nil, err
+			}
 			IP = net.ParseIP(strings.TrimSpace(string(body)))
-			return IP
+			return IP, nil
 		}
 	}
 
-	return net.IP{}
+	return net.IP{}, nil
 }

cmd/cli/regenerate.go

@@ -8,8 +8,11 @@ import (
 	"github.com/spf13/viper"
 )
 
-func Regenerate(hostname string, confirm bool) {
-	config := MustLoadConfigFile()
+func Regenerate(hostname string, confirm bool) error {
+	config, err := LoadConfigFile()
+	if err != nil {
+		return fmt.Errorf("%w - failure to load config file", err)
+	}
 	server := GetServer(config)
 
 	found := false
@@ -21,36 +24,49 @@ func Regenerate(hostname string, confirm bool) {
 	for _, peer := range server.Peers {
 		if peer.Hostname == hostname {
 			privateKey, err := lib.GenerateJSONPrivateKey()
-			check(err, "failed to generate private key")
+			if err != nil {
+				return fmt.Errorf("%w - failed to generate private key", err)
+			}
 
 			preshareKey, err := lib.GenerateJSONKey()
-			check(err, "failed to generate preshared key")
+			if err != nil {
+				return fmt.Errorf("%w - failed to generate preshared key", err)
+			}
 
 			peer.PrivateKey = privateKey
 			peer.PublicKey = privateKey.PublicKey()
 			peer.PresharedKey = preshareKey
 
 			err = config.RemovePeer(hostname)
-			check(err, "failed to regenerate peer")
+			if err != nil {
+				return fmt.Errorf("%w - failed to regenerate peer", err)
+			}
 
 			peerType := viper.GetString("output")
 
 			peerConfigBytes, err := lib.AsciiPeerConfig(peer, peerType, *server)
-			check(err, "failed to get peer configuration")
+			if err != nil {
+				return fmt.Errorf("%w - failed to get peer configuration", err)
+			}
 			os.Stdout.Write(peerConfigBytes.Bytes())
 			found = true
-			config.MustAddPeer(peer)
+			if err = config.AddPeer(peer); err != nil {
+				return fmt.Errorf("%w - failure to add peer", err)
+			}
 
 			break
 		}
 	}
 
 	if !found {
-		ExitFail(fmt.Sprintf("unknown hostname: %s", hostname))
+		return fmt.Errorf("unknown hostname: %s", hostname)
 	}
 
 	// Get a new server configuration so we can update the wg interface with the new peer details
 	server = GetServer(config)
-	config.MustSave()
+	if err = config.Save(); err != nil {
+		return fmt.Errorf("%w - failure saving config", err)
+	}
 	server.ConfigureDevice()
+	return nil
 }

cmd/cli/remove.go

@@ -2,19 +2,27 @@ package cli
 
 import "fmt"
 
-func Remove(hostname string, confirm bool) {
-	conf := MustLoadConfigFile()
+func Remove(hostname string, confirm bool) error {
+	conf, err := LoadConfigFile()
+	if err != nil {
+		return fmt.Errorf("%w - failed to load config", err)
+	}
 
-	err := conf.RemovePeer(hostname)
-	check(err, "failed to update config")
+	if err = conf.RemovePeer(hostname); err != nil {
+		return fmt.Errorf("%w - failed to update config", err)
+	}
 
 	if !confirm {
 		ConfirmOrAbort("Do you really want to remove %s?", hostname)
 	}
 
-	conf.MustSave()
+	if err = conf.Save(); err != nil {
+		return fmt.Errorf("%w - failure to save config", err)
+	}
 	server := GetServer(conf)
 
-	err = server.ConfigureDevice()
-	check(err, fmt.Sprintf("failed to sync server config to wg interface: %s", server.InterfaceName))
+	if err = server.ConfigureDevice(); err != nil {
+		return fmt.Errorf("%w - failed to sync server config to wg interface: %s", err, server.InterfaceName)
+	}
+	return nil
 }