Add podman network create option for bridge mtu

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>

5 files changed, 42 insertions, 2 deletions

diff --git a/cmd/podman/networks/create.go b/cmd/podman/networks/create.go
index 938b8da77..8db4bb89a 100644
--- a/cmd/podman/networks/create.go
+++ b/cmd/podman/networks/create.go
@@ -30,6 +30,7 @@ var (
 var (
 	networkCreateOptions entities.NetworkCreateOptions
 	labels               []string
+	opts                 []string
 )
 
 func networkCreateFlags(cmd *cobra.Command) {
@@ -39,6 +40,10 @@ func networkCreateFlags(cmd *cobra.Command) {
 	flags.StringVarP(&networkCreateOptions.Driver, driverFlagName, "d", "bridge", "driver to manage the network")
 	_ = cmd.RegisterFlagCompletionFunc(driverFlagName, common.AutocompleteNetworkDriver)
 
+	optFlagName := "opt"
+	flags.StringArrayVarP(&opts, optFlagName, "o", []string{}, "Set driver specific options (default [])")
+	_ = cmd.RegisterFlagCompletionFunc(optFlagName, completion.AutocompleteNone)
+
 	gatewayFlagName := "gateway"
 	flags.IPVar(&networkCreateOptions.Gateway, gatewayFlagName, nil, "IPv4 or IPv6 gateway for the subnet")
 	_ = cmd.RegisterFlagCompletionFunc(gatewayFlagName, completion.AutocompleteNone)
@@ -93,6 +98,10 @@ func networkCreate(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return errors.Wrap(err, "failed to parse labels")
 	}
+	networkCreateOptions.Options, err = parse.GetAllLabels([]string{}, opts)
+	if err != nil {
+		return errors.Wrapf(err, "unable to process options")
+	}
 	response, err := registry.ContainerEngine().NetworkCreate(registry.Context(), name, networkCreateOptions)
 	if err != nil {
 		return err
diff --git a/docs/source/markdown/podman-network-create.1.md b/docs/source/markdown/podman-network-create.1.md
index d787809cd..235bf9a6c 100644
--- a/docs/source/markdown/podman-network-create.1.md
+++ b/docs/source/markdown/podman-network-create.1.md
@@ -26,6 +26,13 @@ resolution.
 
 Driver to manage the network (default "bridge").  Currently only `bridge` is supported.
 
+#### **--opt**=*option*, **-o**
+
+Set driver specific options.
+
+For the `bridge` driver the following options are supported: `mtu`.
+The `mtu` option sets the Maximum Transmission Unit (MTU) and takes an integer value.
+
 #### **--gateway**
 
 Define a gateway for the subnet. If you want to provide a gateway address, you must also provide a
diff --git a/libpod/network/create.go b/libpod/network/create.go
index cac438963..50337013d 100644
--- a/libpod/network/create.go
+++ b/libpod/network/create.go
@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strconv"
 
 	"github.com/containernetworking/cni/pkg/version"
 	"github.com/containers/common/pkg/config"
@@ -76,6 +77,21 @@ func validateBridgeOptions(options entities.NetworkCreateOptions) error {
 
 }
 
+// parseMTU parses the mtu option
+func parseMTU(mtu string) (int, error) {
+	if mtu == "" {
+		return 0, nil // default
+	}
+	m, err := strconv.Atoi(mtu)
+	if err != nil {
+		return 0, err
+	}
+	if m < 0 {
+		return 0, errors.Errorf("the value %d for mtu is less than zero", m)
+	}
+	return m, nil
+}
+
 // createBridge creates a CNI network
 func createBridge(name string, options entities.NetworkCreateOptions, runtimeConfig *config.Config) (string, error) {
 	var (
@@ -149,6 +165,11 @@ func createBridge(name string, options entities.NetworkCreateOptions, runtimeCon
 		ipMasq = false
 	}
 
+	mtu, err := parseMTU(options.Options["mtu"])
+	if err != nil {
+		return "", err
+	}
+
 	// obtain host bridge name
 	bridgeDeviceName, err := GetFreeDeviceName(runtimeConfig)
 	if err != nil {
@@ -172,7 +193,7 @@ func createBridge(name string, options entities.NetworkCreateOptions, runtimeCon
 	ncList := NewNcList(name, version.Current(), options.Labels)
 	var plugins []CNIPlugins
 	// TODO need to iron out the role of isDefaultGW and IPMasq
-	bridge := NewHostLocalBridge(bridgeDeviceName, isGateway, false, ipMasq, ipamConfig)
+	bridge := NewHostLocalBridge(bridgeDeviceName, isGateway, false, ipMasq, mtu, ipamConfig)
 	plugins = append(plugins, bridge)
 	plugins = append(plugins, NewPortMapPlugin())
 	plugins = append(plugins, NewFirewallPlugin())
diff --git a/libpod/network/netconflist.go b/libpod/network/netconflist.go
index 3db38485b..8cbad39cb 100644
--- a/libpod/network/netconflist.go
+++ b/libpod/network/netconflist.go
@@ -41,11 +41,12 @@ func NewNcList(name, version string, labels NcLabels) NcList {
 }
 
 // NewHostLocalBridge creates a new LocalBridge for host-local
-func NewHostLocalBridge(name string, isGateWay, isDefaultGW, ipMasq bool, ipamConf IPAMHostLocalConf) *HostLocalBridge {
+func NewHostLocalBridge(name string, isGateWay, isDefaultGW, ipMasq bool, mtu int, ipamConf IPAMHostLocalConf) *HostLocalBridge {
 	hostLocalBridge := HostLocalBridge{
 		PluginType:  "bridge",
 		BrName:      name,
 		IPMasq:      ipMasq,
+		MTU:         mtu,
 		HairpinMode: true,
 		IPAM:        ipamConf,
 	}
diff --git a/pkg/domain/entities/network.go b/pkg/domain/entities/network.go
index f14cac7ef..65a110fd9 100644
--- a/pkg/domain/entities/network.go
+++ b/pkg/domain/entities/network.go
@@ -45,6 +45,8 @@ type NetworkCreateOptions struct {
 	Range      net.IPNet
 	Subnet     net.IPNet
 	IPv6       bool
+	// Mapping of driver options and values.
+	Options map[string]string
 }
 
 // NetworkCreateReport describes a created network for the cli