error when --module is specified on the command level

The --module can only be parsed on the root level.  It cannot work on
the command level, because it must be "manually" parsed on init() to
make sure the specified configuration files/modules are loaded prior to
parsing the flags via Cobra.

Hence move --module from the "persistent" to the "local" flags which
will yield an error instead of doing nothing when being specified on the
command level:

```
$ ./bin/podman run --module=foo.conf --rm alpine
Error: unknown flag: --module
See 'podman run --help'
```

Reported in #20000.

Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

cmd/podman/registry/config.go

@@ -80,7 +80,7 @@ func containersConfModules() ([]string, error) {
 func newPodmanConfig() {
 	modules, err := containersConfModules()
 	if err != nil {
-		fmt.Fprintln(os.Stderr, err.Error())
+		fmt.Fprintf(os.Stderr, "Error parsing containers.conf modules: %v\n", err)
 		os.Exit(1)
 	}
 
@@ -94,7 +94,7 @@ func newPodmanConfig() {
 		Modules:    modules,
 	})
 	if err != nil {
-		fmt.Fprint(os.Stderr, "Failed to obtain podman configuration: "+err.Error())
+		fmt.Fprintf(os.Stderr, "Failed to obtain podman configuration: %v\n", err)
 		os.Exit(1)
 	}
 
@@ -111,7 +111,7 @@ func newPodmanConfig() {
 			mode = entities.TunnelMode
 		}
 	default:
-		fmt.Fprintf(os.Stderr, "%s is not a supported OS", runtime.GOOS)
+		fmt.Fprintf(os.Stderr, "%s is not a supported OS\n", runtime.GOOS)
 		os.Exit(1)
 	}
 

cmd/podman/root.go

@@ -456,7 +456,7 @@ func rootFlags(cmd *cobra.Command, podmanConfig *entities.PodmanConfig) {
 		// as a flag here to a) make sure that rootflags are aware of
 		// this flag and b) to have shell completions.
 		moduleFlagName := "module"
-		pFlags.StringSlice(moduleFlagName, nil, "Load the containers.conf(5) module")
+		lFlags.StringSlice(moduleFlagName, nil, "Load the containers.conf(5) module")
 		_ = cmd.RegisterFlagCompletionFunc(moduleFlagName, common.AutocompleteContainersConfModules)
 
 		// A *hidden* flag to change the database backend.

docs/source/markdown/podman.1.md

@@ -92,7 +92,8 @@ Log messages at and above specified level: __debug__, __info__, __warn__, __erro
 
 Load the specified `containers.conf(5)` module.  Can be an absolute or relative path.  Please refer to `containers.conf(5)` for details.
 
-This feature is not supported on the remote client, including Mac and Windows (excluding WSL2) machines
+This flag is not supported on the remote client, including Mac and Windows (excluding WSL2) machines.
+Further note that the flag is a root-level flag and must be specified before any Podman sub-command.
 
 #### **--network-cmd-path**=*path*
 Path to the `slirp4netns(1)` command binary to use for setting up a slirp4netns network.

test/system/800-config.bats

@@ -93,6 +93,10 @@ EOF
 annotations=['module=$random_data']
 EOF
 
+    run_podman 125 create --module=$conf_tmp -q $IMAGE
+    is "$output" "Error: unknown flag: --module
+See 'podman create --help'" "--module must be specified before the command"
+
     run_podman --module=$conf_tmp create -q $IMAGE
     cid="$output"
     run_podman container inspect $cid --format '{{index .Config.Annotations "module"}}'