Add config

config/config.go

@@ -0,0 +1,175 @@
+package config
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/pelletier/go-toml"
+	"google.golang.org/grpc/credentials"
+)
+
+type Config struct {
+	LogLevel string        `toml:"LogLevel"`
+	Server   *ServerConfig `toml:"Server"`
+	Client   *ClientConfig `toml:"Client"`
+	location string
+}
+type CertificatePaths struct {
+	CertificatePath    string `toml:"CertificatePath"`
+	CertificateKeyPath string `toml:"CertificateKeyPath"`
+}
+
+type ServerConfig struct {
+	GRPC *ServerGRPCConfig `toml:"GRPC"`
+	HTTP *ServerHTTPConfig `toml:"HTTP"`
+}
+type ServerStoreConfig struct {
+	Type          string         `toml:"Type"`
+	FSStoreConfig *FSStoreConfig `toml:"Filesystem"`
+}
+type FSStoreConfig struct {
+	Dir string `toml:"Dir"`
+}
+type ServerGRPCConfig struct {
+	ListenAddr string            `toml:"ListenAddr"`
+	CACerts    *CertificatePaths `toml:"CACerts"`
+	Certs      *CertificatePaths `toml:"Certs"`
+}
+type ServerHTTPConfig struct {
+	ListenAddr string `toml:"ListenAddr"`
+}
+
+type ClientConfig struct {
+	DefaultServer  string            `toml:"DefaultServer"`
+	ServerCertPath string            `toml:"ServerCertPath"`
+	Certs          *CertificatePaths `toml:"Certs"`
+}
+
+func FromDefault() *Config {
+	cfg := &Config{
+		LogLevel: "INFO",
+		Server: &ServerConfig{
+			GRPC: &ServerGRPCConfig{
+				ListenAddr: ":50051",
+				CACerts:    &CertificatePaths{},
+				Certs:      &CertificatePaths{},
+			},
+			HTTP: &ServerHTTPConfig{
+				ListenAddr: ":8089",
+			},
+		},
+		Client: &ClientConfig{},
+	}
+
+	return cfg
+}
+
+func FromReader(r io.Reader) (*Config, error) {
+	decoder := toml.NewDecoder(r)
+	c := FromDefault()
+	if err := decoder.Decode(c); err != nil {
+		return nil, fmt.Errorf("unable to read config: %w", err)
+	}
+
+	return c, nil
+}
+
+func FromFile(path string) (*Config, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("unable to open config-file: %w", err)
+	}
+	defer f.Close()
+
+	cfg, err := FromReader(f)
+	if err == nil {
+		cfg.location = path
+	}
+
+	return cfg, err
+}
+
+func FromDefaultLocations() (*Config, error) {
+	defaultLocations := []string{
+		"ezshare.toml",
+	}
+	userConfigDir, err := os.UserConfigDir()
+	if err != nil {
+		defaultLocations = append(defaultLocations, filepath.Join(userConfigDir, "ezshare", "ezshare.toml"))
+	}
+
+	for _, location := range defaultLocations {
+		if _, err := os.Stat(location); err == nil {
+			return FromFile(location)
+		}
+	}
+	return nil, fmt.Errorf("config not found")
+}
+
+func (c *Config) Location() string {
+	return c.location
+}
+
+func (cp *CertificatePaths) GetCertBytes() ([]byte, error) {
+	f, err := os.Open(cp.CertificatePath)
+	if err != nil {
+		return nil, err
+	}
+	return ioutil.ReadAll(f)
+}
+
+func (cp *CertificatePaths) GetKeyBytes() ([]byte, error) {
+	f, err := os.Open(cp.CertificateKeyPath)
+	if err != nil {
+		return nil, err
+	}
+	return ioutil.ReadAll(f)
+}
+
+func (cc *ClientConfig) ServerCertBytes() ([]byte, error) {
+	f, err := os.Open(cc.ServerCertPath)
+	if err != nil {
+		return nil, fmt.Errorf("unable to open server certificate: %w", err)
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read client server certificate: %w", err)
+	}
+	return data, nil
+}
+
+func (cc *ClientConfig) Creds() (credentials.TransportCredentials, error) {
+	srvCertBytes, err := cc.ServerCertBytes()
+	if err != nil {
+		return nil, err
+	}
+	clientCertBytes, err := cc.Certs.GetCertBytes()
+	if err != nil {
+		return nil, fmt.Errorf("unable to read client cert: %w", err)
+	}
+	clientKeyBytes, err := cc.Certs.GetKeyBytes()
+	if err != nil {
+		return nil, fmt.Errorf("unable to read client cert: %w", err)
+	}
+	certPool := x509.NewCertPool()
+	if !certPool.AppendCertsFromPEM(srvCertBytes) {
+		return nil, fmt.Errorf("unable to load ca cert")
+	}
+	clientCert, err := tls.X509KeyPair(clientCertBytes, clientKeyBytes)
+	if err != nil {
+		return nil, fmt.Errorf("unable to load client cert: %s", err)
+	}
+	config := &tls.Config{
+		Certificates: []tls.Certificate{clientCert},
+		RootCAs:      certPool,
+	}
+	return credentials.NewTLS(config), nil
+
+}