Allow multiple --network flags for podman run/create

We allow a container to be connected to several cni networks
but only if they are listed comma sperated. This is not intuitive
for users especially since the flag parsing allows multiple string
flags but only would take the last value. see: spf13/pflag#72

Also get rid of the extra parsing logic for pods. The invalid options
are already handled by `pkg/specgen`.

A test is added to prevent a future regression.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

2 files changed, 20 insertions, 42 deletions

diff --git a/cmd/podman/common/netflags.go b/cmd/podman/common/netflags.go
index cae52ccaa..898d65bd0 100644
--- a/cmd/podman/common/netflags.go
+++ b/cmd/podman/common/netflags.go
@@ -59,8 +59,8 @@ func DefineNetFlags(cmd *cobra.Command) {
 	_ = cmd.RegisterFlagCompletionFunc(macAddressFlagName, completion.AutocompleteNone)
 
 	networkFlagName := "network"
-	netFlags.String(
-		networkFlagName, containerConfig.NetNS(),
+	netFlags.StringArray(
+		networkFlagName, []string{containerConfig.NetNS()},
 		"Connect a container to a network",
 	)
 	_ = cmd.RegisterFlagCompletionFunc(networkFlagName, AutocompleteNetworks)
@@ -194,25 +194,29 @@ func NetFlagsToNetOptions(cmd *cobra.Command) (*entities.NetOptions, error) {
 	}
 
 	if cmd.Flags().Changed("network") {
-		network, err := cmd.Flags().GetString("network")
+		networks, err := cmd.Flags().GetStringArray("network")
 		if err != nil {
 			return nil, err
 		}
+		for i, network := range networks {
+			parts := strings.SplitN(network, ":", 2)
 
-		parts := strings.SplitN(network, ":", 2)
-
-		ns, cniNets, err := specgen.ParseNetworkNamespace(network)
-		if err != nil {
-			return nil, err
-		}
+			ns, cniNets, err := specgen.ParseNetworkNamespace(network)
+			if err != nil {
+				return nil, err
+			}
+			if i > 0 && (len(cniNets) == 0 || len(opts.CNINetworks) == 0) {
+				return nil, errors.Errorf("network conflict between type %s and %s", opts.Network.NSMode, ns.NSMode)
+			}
 
-		if len(parts) > 1 {
-			opts.NetworkOptions = make(map[string][]string)
-			opts.NetworkOptions[parts[0]] = strings.Split(parts[1], ",")
-			cniNets = nil
+			if len(parts) > 1 {
+				opts.NetworkOptions = make(map[string][]string)
+				opts.NetworkOptions[parts[0]] = strings.Split(parts[1], ",")
+				cniNets = nil
+			}
+			opts.Network = ns
+			opts.CNINetworks = append(opts.CNINetworks, cniNets...)
 		}
-		opts.Network = ns
-		opts.CNINetworks = cniNets
 	}
 
 	aliases, err := cmd.Flags().GetStringSlice("network-alias")
diff --git a/cmd/podman/pods/create.go b/cmd/podman/pods/create.go
index 449d60bb9..57b895e83 100644
--- a/cmd/podman/pods/create.go
+++ b/cmd/podman/pods/create.go
@@ -171,33 +171,7 @@ func create(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-	createOptions.Net.Network = specgen.Namespace{}
-	if cmd.Flag("network").Changed {
-		netInput, err := cmd.Flags().GetString("network")
-		if err != nil {
-			return err
-		}
-		parts := strings.SplitN(netInput, ":", 2)
-
-		n := specgen.Namespace{}
-		switch {
-		case netInput == "bridge":
-			n.NSMode = specgen.Bridge
-		case netInput == "host":
-			n.NSMode = specgen.Host
-		case netInput == "slirp4netns", strings.HasPrefix(netInput, "slirp4netns:"):
-			n.NSMode = specgen.Slirp
-			if len(parts) > 1 {
-				createOptions.Net.NetworkOptions = make(map[string][]string)
-				createOptions.Net.NetworkOptions[parts[0]] = strings.Split(parts[1], ",")
-			}
-		default:
-			// Container and NS mode are presently unsupported
-			n.NSMode = specgen.Bridge
-			createOptions.Net.CNINetworks = strings.Split(netInput, ",")
-		}
-		createOptions.Net.Network = n
-	}
+
 	if len(createOptions.Net.PublishPorts) > 0 {
 		if !createOptions.Infra {
 			return errors.Errorf("you must have an infra container to publish port bindings to the host")