Add check command to verify configuration

commands/check.go

@@ -0,0 +1,110 @@
+/*
+Copyright The Guard Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package commands
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"strings"
+
+	"go.kubeguard.dev/guard/auth"
+	"go.kubeguard.dev/guard/auth/providers/azure"
+	"go.kubeguard.dev/guard/auth/providers/github"
+	"go.kubeguard.dev/guard/auth/providers/gitlab"
+	"go.kubeguard.dev/guard/auth/providers/google"
+	"go.kubeguard.dev/guard/auth/providers/ldap"
+	"go.kubeguard.dev/guard/server"
+
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+func NewCmdCheck() *cobra.Command {
+	var (
+		opts         = server.NewAuthRecommendedOptions()
+		githubOrg    string
+		googleDomain string
+	)
+	cmd := &cobra.Command{
+		Use:   "check PROVIDER",
+		Short: "Checks a token from STDIN and prints the obtained user information.",
+		Long: `Checks a token from STDIN and prints the obtained user information. The check
+command accepts the same flags as the run command. This way you can verify that
+your configuration would produce the expected result for a certain token.
+
+For the Github and Google provider you additionally have to configure the flag
+--github.org resp. --google.domain. In the running server these values are passed
+as the common name (CN) of the client certificate.`,
+		Args:              cobra.MinimumNArgs(1),
+		DisableAutoGenTag: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			provider := args[0]
+
+			var (
+				authenticator auth.Interface
+				err           error
+			)
+			switch strings.ToLower(provider) {
+			case github.OrgType:
+				if githubOrg == "" {
+					return fmt.Errorf("github organization not configured. set it with --github.org")
+				}
+				authenticator = github.New(opts.Github, githubOrg)
+			case google.OrgType:
+				if googleDomain == "" {
+					return fmt.Errorf("google domain not configured. set it with --google.domain")
+				}
+				authenticator, err = google.New(cmd.Context(), opts.Google, googleDomain)
+			case gitlab.OrgType:
+				authenticator = gitlab.New(opts.Gitlab)
+			case azure.OrgType:
+				authenticator, err = azure.New(cmd.Context(), opts.Azure)
+			case ldap.OrgType:
+				authenticator = ldap.New(opts.LDAP)
+			default:
+				return errors.Errorf("unknown provider '%s'", provider)
+			}
+			if err != nil {
+				return err
+			}
+
+			token, err := io.ReadAll(cmd.InOrStdin())
+			if err != nil {
+				return fmt.Errorf("failed to read token from stdin")
+			}
+
+			userinfo, err := authenticator.Check(cmd.Context(), string(token))
+			if err != nil {
+				return err
+			}
+
+			out, err := json.MarshalIndent(userinfo, "", "  ")
+			if err != nil {
+				return err
+			}
+
+			cmd.Println(string(out))
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVar(&githubOrg, "github.org", githubOrg, "Github organization. With the running guard server this value is passed as common name (CN) of the client certificate")
+	cmd.Flags().StringVar(&googleDomain, "google.domain", googleDomain, "Google domain. With the running guard server this value is passed as common name (CN) of the client certificate")
+	opts.AddFlags(cmd.Flags())
+	return cmd
+}

commands/root.go

@@ -32,6 +32,7 @@ func NewRootCmd() *cobra.Command {
 	cmd.AddCommand(NewCmdGet())
 	cmd.AddCommand(NewCmdRun())
 	cmd.AddCommand(NewCmdLogin())
+	cmd.AddCommand(NewCmdCheck())
 	cmd.AddCommand(v.NewCmdVersion())
 	return cmd
 }