Add flag to overwrite network backend from config

To make testing easier we can overwrite the network backend with the
global `--network-backend` option.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

cmd/podman/common/completion.go

@@ -1163,6 +1163,13 @@ func AutocompleteEventBackend(cmd *cobra.Command, args []string, toComplete stri
 	return types, cobra.ShellCompDirectiveNoFileComp
 }
 
+// AutocompleteNetworkBackend - Autocomplete network backend options.
+// -> "cni", "netavark"
+func AutocompleteNetworkBackend(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+	types := []string{"cni", "netavark"}
+	return types, cobra.ShellCompDirectiveNoFileComp
+}
+
 // AutocompleteLogLevel - Autocomplete log level options.
 // -> "trace", "debug", "info", "warn", "error", "fatal", "panic"
 func AutocompleteLogLevel(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {

cmd/podman/root.go

@@ -357,6 +357,11 @@ func rootFlags(cmd *cobra.Command, opts *entities.PodmanConfig) {
 		pFlags.StringVar(&cfg.Engine.Namespace, namespaceFlagName, cfg.Engine.Namespace, "Set the libpod namespace, used to create separate views of the containers and pods on the system")
 		_ = cmd.RegisterFlagCompletionFunc(namespaceFlagName, completion.AutocompleteNone)
 
+		networkBackendFlagName := "network-backend"
+		pFlags.StringVar(&cfg.Network.NetworkBackend, networkBackendFlagName, cfg.Network.NetworkBackend, `Network backend to use ("cni"|"netavark")`)
+		_ = cmd.RegisterFlagCompletionFunc(networkBackendFlagName, common.AutocompleteNetworkBackend)
+		pFlags.MarkHidden(networkBackendFlagName)
+
 		rootFlagName := "root"
 		pFlags.StringVar(&cfg.Engine.StaticDir, rootFlagName, "", "Path to the root directory in which data, including images, is stored")
 		_ = cmd.RegisterFlagCompletionFunc(rootFlagName, completion.AutocompleteDefault)

libpod/options.go

@@ -227,6 +227,19 @@ func WithNetworkCmdPath(path string) RuntimeOption {
 	}
 }
 
+// WithNetworkBackend specifies the name of the network backend.
+func WithNetworkBackend(name string) RuntimeOption {
+	return func(rt *Runtime) error {
+		if rt.valid {
+			return define.ErrRuntimeFinalized
+		}
+
+		rt.config.Network.NetworkBackend = name
+
+		return nil
+	}
+}
+
 // WithCgroupManager specifies the manager implementation name which is used to
 // handle cgroups for containers.
 // Current valid values are "cgroupfs" and "systemd".

libpod/runtime.go

@@ -499,6 +499,10 @@ func makeRuntime(ctx context.Context, runtime *Runtime) (retErr error) {
 		if err != nil {
 			return errors.Wrapf(err, "could not create network interface")
 		}
+		if runtime.config.Network.NetworkBackend == "" {
+			// set backend to cni so that podman info can display it
+			runtime.config.Network.NetworkBackend = "cni"
+		}
 
 	case "netavark":
 		netavarkBin, err := runtime.config.FindHelperBinary("netavark", false)

pkg/domain/infra/runtime_libpod.go

@@ -200,6 +200,9 @@ func getRuntime(ctx context.Context, fs *flag.FlagSet, opts *engineOpts) (*libpo
 	if fs.Changed("network-cmd-path") {
 		options = append(options, libpod.WithNetworkCmdPath(cfg.Engine.NetworkCmdPath))
 	}
+	if fs.Changed("network-backend") {
+		options = append(options, libpod.WithNetworkBackend(cfg.Network.NetworkBackend))
+	}
 
 	if fs.Changed("events-backend") {
 		options = append(options, libpod.WithEventsLogger(cfg.Engine.EventsLogger))