conf: use dedicated interface to unmarshal from environment

internal/conf/authmethod.go

@@ -8,34 +8,6 @@ import (
 	"github.com/aler9/gortsplib/pkg/headers"
 )
 
-func unmarshalStringSlice(b []byte) ([]string, error) {
-	var in interface{}
-	if err := json.Unmarshal(b, &in); err != nil {
-		return nil, err
-	}
-
-	var slice []string
-
-	switch it := in.(type) {
-	case string: // from environment variables
-		slice = strings.Split(it, ",")
-
-	case []interface{}: // from yaml
-		for _, e := range it {
-			et, ok := e.(string)
-			if !ok {
-				return nil, fmt.Errorf("cannot unmarshal from %T", e)
-			}
-			slice = append(slice, et)
-		}
-
-	default:
-		return nil, fmt.Errorf("cannot unmarshal from %T", in)
-	}
-
-	return slice, nil
-}
-
 // AuthMethods is the authMethods parameter.
 type AuthMethods []headers.AuthMethod
 
@@ -58,12 +30,12 @@ func (d AuthMethods) MarshalJSON() ([]byte, error) {
 
 // UnmarshalJSON unmarshals a AuthMethods from JSON.
 func (d *AuthMethods) UnmarshalJSON(b []byte) error {
-	slice, err := unmarshalStringSlice(b)
-	if err != nil {
+	var in []string
+	if err := json.Unmarshal(b, &in); err != nil {
 		return err
 	}
 
-	for _, v := range slice {
+	for _, v := range in {
 		switch v {
 		case "basic":
 			*d = append(*d, headers.AuthBasic)
@@ -78,3 +50,8 @@ func (d *AuthMethods) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+func (d *AuthMethods) unmarshalEnv(s string) error {
+	byts, _ := json.Marshal(strings.Split(s, ","))
+	return d.UnmarshalJSON(byts)
+}

internal/conf/credential.go

@@ -35,3 +35,7 @@ func (d *Credential) UnmarshalJSON(b []byte) error {
 	*d = Credential(in)
 	return nil
 }
+
+func (d *Credential) unmarshalEnv(s string) error {
+	return d.UnmarshalJSON([]byte(`"` + s + `"`))
+}

internal/conf/encryption.go

@@ -56,3 +56,7 @@ func (d *Encryption) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+func (d *Encryption) unmarshalEnv(s string) error {
+	return d.UnmarshalJSON([]byte(`"` + s + `"`))
+}

internal/conf/env.go

@@ -1,7 +1,6 @@
 package conf
 
 import (
-	"encoding/json"
 	"fmt"
 	"os"
 	"reflect"
@@ -9,12 +8,16 @@ import (
 	"strings"
 )
 
+type envUnmarshaler interface {
+	unmarshalEnv(string) error
+}
+
 func loadEnvInternal(env map[string]string, prefix string, rv reflect.Value) error {
 	rt := rv.Type()
 
-	if i, ok := rv.Addr().Interface().(json.Unmarshaler); ok {
+	if i, ok := rv.Addr().Interface().(envUnmarshaler); ok {
 		if ev, ok := env[prefix]; ok {
-			err := i.UnmarshalJSON([]byte(`"` + ev + `"`))
+			err := i.unmarshalEnv(ev)
 			if err != nil {
 				return fmt.Errorf("%s: %s", prefix, err)
 			}

internal/conf/ipsornets.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net"
+	"strings"
 )
 
 // IPsOrNets is a parameter that acceps IPs or subnets.
@@ -22,16 +23,16 @@ func (d IPsOrNets) MarshalJSON() ([]byte, error) {
 
 // UnmarshalJSON unmarshals a IPsOrNets from JSON.
 func (d *IPsOrNets) UnmarshalJSON(b []byte) error {
-	slice, err := unmarshalStringSlice(b)
-	if err != nil {
+	var in []string
+	if err := json.Unmarshal(b, &in); err != nil {
 		return err
 	}
 
-	if len(slice) == 0 {
+	if len(in) == 0 {
 		return nil
 	}
 
-	for _, t := range slice {
+	for _, t := range in {
 		if _, ipnet, err := net.ParseCIDR(t); err == nil {
 			*d = append(*d, ipnet)
 		} else if ip := net.ParseIP(t); ip != nil {
@@ -43,3 +44,8 @@ func (d *IPsOrNets) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+func (d *IPsOrNets) unmarshalEnv(s string) error {
+	byts, _ := json.Marshal(strings.Split(s, ","))
+	return d.UnmarshalJSON(byts)
+}

internal/conf/logdestination.go

@@ -3,6 +3,7 @@ package conf
 import (
 	"encoding/json"
 	"fmt"
+	"strings"
 
 	"github.com/aler9/rtsp-simple-server/internal/logger"
 )
@@ -38,14 +39,14 @@ func (d LogDestinations) MarshalJSON() ([]byte, error) {
 
 // UnmarshalJSON unmarshals a LogDestinations from JSON.
 func (d *LogDestinations) UnmarshalJSON(b []byte) error {
-	slice, err := unmarshalStringSlice(b)
-	if err != nil {
+	var in []string
+	if err := json.Unmarshal(b, &in); err != nil {
 		return err
 	}
 
 	*d = make(LogDestinations)
 
-	for _, proto := range slice {
+	for _, proto := range in {
 		switch proto {
 		case "stdout":
 			(*d)[logger.DestinationStdout] = struct{}{}
@@ -63,3 +64,8 @@ func (d *LogDestinations) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+func (d *LogDestinations) unmarshalEnv(s string) error {
+	byts, _ := json.Marshal(strings.Split(s, ","))
+	return d.UnmarshalJSON(byts)
+}

internal/conf/loglevel.go

@@ -51,3 +51,7 @@ func (d *LogLevel) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+func (d *LogLevel) unmarshalEnv(s string) error {
+	return d.UnmarshalJSON([]byte(`"` + s + `"`))
+}

internal/conf/protocol.go

@@ -3,6 +3,7 @@ package conf
 import (
 	"encoding/json"
 	"fmt"
+	"strings"
 )
 
 // Protocol is a RTSP stream protocol.
@@ -46,14 +47,14 @@ func (d Protocols) MarshalJSON() ([]byte, error) {
 
 // UnmarshalJSON unmarshals a Protocols from JSON.
 func (d *Protocols) UnmarshalJSON(b []byte) error {
-	slice, err := unmarshalStringSlice(b)
-	if err != nil {
+	var in []string
+	if err := json.Unmarshal(b, &in); err != nil {
 		return err
 	}
 
 	*d = make(Protocols)
 
-	for _, proto := range slice {
+	for _, proto := range in {
 		switch proto {
 		case "udp":
 			(*d)[ProtocolUDP] = struct{}{}
@@ -71,3 +72,8 @@ func (d *Protocols) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+func (d *Protocols) unmarshalEnv(s string) error {
+	byts, _ := json.Marshal(strings.Split(s, ","))
+	return d.UnmarshalJSON(byts)
+}

internal/conf/sourceprotocol.go

@@ -62,3 +62,7 @@ func (d *SourceProtocol) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+func (d *SourceProtocol) unmarshalEnv(s string) error {
+	return d.UnmarshalJSON([]byte(`"` + s + `"`))
+}

internal/conf/stringduration.go

@@ -29,3 +29,7 @@ func (d *StringDuration) UnmarshalJSON(b []byte) error {
 
 	return nil
 }
+
+func (d *StringDuration) unmarshalEnv(s string) error {
+	return d.UnmarshalJSON([]byte(`"` + s + `"`))
+}