add support for ACME compliant certificate authorities

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

cmd/acme.go

@@ -0,0 +1,55 @@
+package cmd
+
+import (
+	"os"
+
+	"github.com/rs/zerolog"
+	"github.com/spf13/cobra"
+
+	"github.com/drakkan/sftpgo/v2/acme"
+	"github.com/drakkan/sftpgo/v2/config"
+	"github.com/drakkan/sftpgo/v2/logger"
+	"github.com/drakkan/sftpgo/v2/util"
+)
+
+var (
+	acmeCmd = &cobra.Command{
+		Use:   "acme",
+		Short: "Obtain TLS certificates from ACME-based CAs like Let's Encrypt",
+	}
+	acmeRunCmd = &cobra.Command{
+		Use:   "run",
+		Short: "Register your account and obtain certificates",
+		Long: `This command must be run to obtain TLS certificates the first time or every
+time you add a new domain to your configuration file.
+Certificates are saved in the configured "certs_path".
+After this initial step, the certificates are automatically checked and
+renewed by the SFTPGo service
+`,
+		Run: func(cmd *cobra.Command, args []string) {
+			logger.DisableLogger()
+			logger.EnableConsoleLogger(zerolog.DebugLevel)
+			configDir = util.CleanDirInput(configDir)
+			err := config.LoadConfig(configDir, configFile)
+			if err != nil {
+				logger.ErrorToConsole("Unable to initialize data provider, config load error: %v", err)
+				return
+			}
+			acmeConfig := config.GetACMEConfig()
+			err = acmeConfig.Initialize(configDir, false)
+			if err != nil {
+				logger.ErrorToConsole("Unable to initialize ACME configuration: %v", err)
+			}
+			if err = acme.GetCertificates(); err != nil {
+				logger.ErrorToConsole("Cannot get certificates: %v", err)
+				os.Exit(1)
+			}
+		},
+	}
+)
+
+func init() {
+	addConfigFlags(acmeRunCmd)
+	acmeCmd.AddCommand(acmeRunCmd)
+	rootCmd.AddCommand(acmeCmd)
+}