external auth: add example HTTP server to use as authentication hook

The server authenticate against an LDAP server.

examples/ldapauthserver/cmd/root.go

@@ -0,0 +1,137 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/drakkan/sftpgo/ldapauthserver/config"
+	"github.com/drakkan/sftpgo/ldapauthserver/utils"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+const (
+	logSender           = "cmd"
+	configDirFlag       = "config-dir"
+	configDirKey        = "config_dir"
+	configFileFlag      = "config-file"
+	configFileKey       = "config_file"
+	logFilePathFlag     = "log-file-path"
+	logFilePathKey      = "log_file_path"
+	logMaxSizeFlag      = "log-max-size"
+	logMaxSizeKey       = "log_max_size"
+	logMaxBackupFlag    = "log-max-backups"
+	logMaxBackupKey     = "log_max_backups"
+	logMaxAgeFlag       = "log-max-age"
+	logMaxAgeKey        = "log_max_age"
+	logCompressFlag     = "log-compress"
+	logCompressKey      = "log_compress"
+	logVerboseFlag      = "log-verbose"
+	logVerboseKey       = "log_verbose"
+	profilerFlag        = "profiler"
+	profilerKey         = "profiler"
+	defaultConfigDir    = "."
+	defaultConfigName   = config.DefaultConfigName
+	defaultLogFile      = "ldapauth.log"
+	defaultLogMaxSize   = 10
+	defaultLogMaxBackup = 5
+	defaultLogMaxAge    = 28
+	defaultLogCompress  = false
+	defaultLogVerbose   = true
+)
+
+var (
+	configDir     string
+	configFile    string
+	logFilePath   string
+	logMaxSize    int
+	logMaxBackups int
+	logMaxAge     int
+	logCompress   bool
+	logVerbose    bool
+
+	rootCmd = &cobra.Command{
+		Use:   "ldapauthserver",
+		Short: "LDAP Authentication Server for SFTPGo",
+	}
+)
+
+func init() {
+	version := utils.GetAppVersion()
+	rootCmd.Flags().BoolP("version", "v", false, "")
+	rootCmd.Version = version.GetVersionAsString()
+	rootCmd.SetVersionTemplate(`{{printf "LDAP Authentication Server version: "}}{{printf "%s" .Version}}
+`)
+}
+
+// Execute adds all child commands to the root command and sets flags appropriately.
+// This is called by main.main(). It only needs to happen once to the rootCmd.
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func addConfigFlags(cmd *cobra.Command) {
+	viper.SetDefault(configDirKey, defaultConfigDir)
+	viper.BindEnv(configDirKey, "LDAPAUTH_CONFIG_DIR")
+	cmd.Flags().StringVarP(&configDir, configDirFlag, "c", viper.GetString(configDirKey),
+		"Location for the config dir. This directory should contain the \"ldapauth\" configuration file or the configured "+
+			"config-file. This flag can be set using LDAPAUTH_CONFIG_DIR env var too.")
+	viper.BindPFlag(configDirKey, cmd.Flags().Lookup(configDirFlag))
+
+	viper.SetDefault(configFileKey, defaultConfigName)
+	viper.BindEnv(configFileKey, "LDAPAUTH_CONFIG_FILE")
+	cmd.Flags().StringVarP(&configFile, configFileFlag, "f", viper.GetString(configFileKey),
+		"Name for the configuration file. It must be the name of a file stored in config-dir not the absolute path to the "+
+			"configuration file. The specified file name must have no extension we automatically load JSON, YAML, TOML, HCL and "+
+			"Java properties. Therefore if you set \"ldapauth\" then \"ldapauth.toml\", \"ldapauth.yaml\" and so on are searched. "+
+			"This flag can be set using LDAPAUTH_CONFIG_FILE env var too.")
+	viper.BindPFlag(configFileKey, cmd.Flags().Lookup(configFileFlag))
+}
+
+func addServeFlags(cmd *cobra.Command) {
+	addConfigFlags(cmd)
+
+	viper.SetDefault(logFilePathKey, defaultLogFile)
+	viper.BindEnv(logFilePathKey, "LDAPAUTH_LOG_FILE_PATH")
+	cmd.Flags().StringVarP(&logFilePath, logFilePathFlag, "l", viper.GetString(logFilePathKey),
+		"Location for the log file. Leave empty to write logs to the standard output. This flag can be set using LDAPAUTH_LOG_FILE_PATH "+
+			"env var too.")
+	viper.BindPFlag(logFilePathKey, cmd.Flags().Lookup(logFilePathFlag))
+
+	viper.SetDefault(logMaxSizeKey, defaultLogMaxSize)
+	viper.BindEnv(logMaxSizeKey, "LDAPAUTH_LOG_MAX_SIZE")
+	cmd.Flags().IntVarP(&logMaxSize, logMaxSizeFlag, "s", viper.GetInt(logMaxSizeKey),
+		"Maximum size in megabytes of the log file before it gets rotated. This flag can be set using LDAPAUTH_LOG_MAX_SIZE "+
+			"env var too. It is unused if log-file-path is empty.")
+	viper.BindPFlag(logMaxSizeKey, cmd.Flags().Lookup(logMaxSizeFlag))
+
+	viper.SetDefault(logMaxBackupKey, defaultLogMaxBackup)
+	viper.BindEnv(logMaxBackupKey, "LDAPAUTH_LOG_MAX_BACKUPS")
+	cmd.Flags().IntVarP(&logMaxBackups, "log-max-backups", "b", viper.GetInt(logMaxBackupKey),
+		"Maximum number of old log files to retain. This flag can be set using LDAPAUTH_LOG_MAX_BACKUPS env var too. "+
+			"It is unused if log-file-path is empty.")
+	viper.BindPFlag(logMaxBackupKey, cmd.Flags().Lookup(logMaxBackupFlag))
+
+	viper.SetDefault(logMaxAgeKey, defaultLogMaxAge)
+	viper.BindEnv(logMaxAgeKey, "LDAPAUTH_LOG_MAX_AGE")
+	cmd.Flags().IntVarP(&logMaxAge, "log-max-age", "a", viper.GetInt(logMaxAgeKey),
+		"Maximum number of days to retain old log files. This flag can be set using LDAPAUTH_LOG_MAX_AGE env var too. "+
+			"It is unused if log-file-path is empty.")
+	viper.BindPFlag(logMaxAgeKey, cmd.Flags().Lookup(logMaxAgeFlag))
+
+	viper.SetDefault(logCompressKey, defaultLogCompress)
+	viper.BindEnv(logCompressKey, "LDAPAUTH_LOG_COMPRESS")
+	cmd.Flags().BoolVarP(&logCompress, logCompressFlag, "z", viper.GetBool(logCompressKey), "Determine if the rotated "+
+		"log files should be compressed using gzip. This flag can be set using LDAPAUTH_LOG_COMPRESS env var too. "+
+		"It is unused if log-file-path is empty.")
+	viper.BindPFlag(logCompressKey, cmd.Flags().Lookup(logCompressFlag))
+
+	viper.SetDefault(logVerboseKey, defaultLogVerbose)
+	viper.BindEnv(logVerboseKey, "LDAPAUTH_LOG_VERBOSE")
+	cmd.Flags().BoolVarP(&logVerbose, logVerboseFlag, "v", viper.GetBool(logVerboseKey), "Enable verbose logs. "+
+		"This flag can be set using LDAPAUTH_LOG_VERBOSE env var too.")
+	viper.BindPFlag(logVerboseKey, cmd.Flags().Lookup(logVerboseFlag))
+}