MM-56632 Display warning if requested mage size exceeds max (#26022) (#27216)

server/cmd/mmctl/commands/root.go

@@ -108,6 +108,11 @@ var RootCmd = &cobra.Command{
 		}
 		quiet := viper.GetBool("quiet")
 		printer.SetQuiet(quiet)
+
+		perPage, err := cmd.Flags().GetInt("per-page")
+		if err == nil && perPage > MaxPageSize {
+			printer.PrintError(fmt.Sprintf("Per page value is greater than the maximum allowed. Mattermost might only return %d items.", MaxPageSize))
+		}
 	},
 	PersistentPostRun: func(cmd *cobra.Command, args []string) {
 		_ = printer.Flush()

server/cmd/mmctl/commands/utils.go

@@ -16,6 +16,7 @@ import (
 
 const (
 	DefaultPageSize = 200
+	MaxPageSize     = 200
 )
 
 func checkInteractiveTerminal() error {