Implement IPA IAM backend (#1005)

feat: FreeIPA IAM implementation

This implements the GetUserAccount() IAM support for accounts stored
within FreeIPA service. This is not implementing any of the account
management functions such as create, update, delete, list IAM accounts,
so is not intended to allow versitygw to manage the IAM accounts within
the FreeIPA service.
---------

Co-authored-by: Yuriy Halytskyy <yuriy.halytskyy@gmail.com>

cmd/versitygw/main.go

@@ -74,6 +74,9 @@ var (
 	metricsService                           string
 	statsdServers                            string
 	dogstatsServers                          string
+	ipaHost, ipaVaultName                    string
+	ipaUser, ipaPassword                     string
+	ipaInsecure, ipaDebug                    bool
 )
 
 var (
@@ -206,6 +209,7 @@ func initFlags() []cli.Flag {
 		&cli.BoolFlag{
 			Name:        "debug",
 			Usage:       "enable debug output",
+			Value:       false,
 			EnvVars:     []string{"VGW_DEBUG"},
 			Destination: &debug,
 		},
@@ -506,6 +510,42 @@ func initFlags() []cli.Flag {
 			Aliases:     []string{"mds"},
 			Destination: &dogstatsServers,
 		},
+		&cli.StringFlag{
+			Name:        "ipa-host",
+			Usage:       "FreeIPA server url e.g. https://ipa.example.test",
+			EnvVars:     []string{"VGW_IPA_HOST"},
+			Destination: &ipaHost,
+		},
+		&cli.StringFlag{
+			Name:        "ipa-vault-name",
+			Usage:       "A name of the user vault containing their secret",
+			EnvVars:     []string{"VGW_IPA_VAULT_NAME"},
+			Destination: &ipaVaultName,
+		},
+		&cli.StringFlag{
+			Name:        "ipa-user",
+			Usage:       "Username used to connect to FreeIPA. Needs permissions to read user vault contents",
+			EnvVars:     []string{"VGW_IPA_USER"},
+			Destination: &ipaUser,
+		},
+		&cli.StringFlag{
+			Name:        "ipa-password",
+			Usage:       "Password of the user used to connect to FreeIPA.",
+			EnvVars:     []string{"VGW_IPA_PASSWORD"},
+			Destination: &ipaPassword,
+		},
+		&cli.BoolFlag{
+			Name:        "ipa-insecure",
+			Usage:       "Verify TLS certificate of FreeIPA server. Default is 'true'.",
+			EnvVars:     []string{"VGW_IPA_INSECURE"},
+			Destination: &ipaInsecure,
+		},
+		&cli.BoolFlag{
+			Name:        "ipa-debug",
+			Usage:       "FreeIPA IAM debug output",
+			EnvVars:     []string{"VGW_IPA_DEBUG"},
+			Destination: &ipaDebug,
+		},
 	}
 }
 
@@ -623,6 +663,12 @@ func runGateway(ctx context.Context, be backend.Backend) error {
 		CacheDisable:           iamCacheDisable,
 		CacheTTL:               iamCacheTTL,
 		CachePrune:             iamCachePrune,
+		IpaHost:                ipaHost,
+		IpaVaultName:           ipaVaultName,
+		IpaUser:                ipaUser,
+		IpaPassword:            ipaPassword,
+		IpaInsecure:            ipaInsecure,
+		IpaDebug:               ipaDebug,
 	})
 	if err != nil {
 		return fmt.Errorf("setup iam: %w", err)