Added serve command to start an identity provider server

cmd/serve.go

@@ -0,0 +1,31 @@
+package cmd
+
+import (
+	opaal "davidallendj/opaal/internal"
+	"errors"
+	"fmt"
+	"net/http"
+
+	"github.com/spf13/cobra"
+)
+
+var exampleCmd = &cobra.Command{
+	Use:   "serve",
+	Short: "Start an simple identity provider server",
+	Long:  "The built-in identity provider is not (nor meant to be) a complete OIDC implementation and behaves like an external IdP",
+	Run: func(cmd *cobra.Command, args []string) {
+		s := opaal.NewServerWithConfig(&config)
+		// FIXME: change how the server address is set with `NewServerWithConfig`
+		s.Server.Addr = fmt.Sprintf("%s:%d", s.Issuer.Host, s.Issuer.Port)
+		err := s.StartIdentityProvider()
+		if errors.Is(err, http.ErrServerClosed) {
+			fmt.Printf("Identity provider server closed.\n")
+		} else if err != nil {
+			fmt.Errorf("failed to start server: %v", err)
+		}
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(exampleCmd)
+}