Refactor out interface specific information from execdriver.Network

Docker-DCO-1.1-Signed-off-by: Timothy Hobbs <timothyhobbs@seznam.cz> (github: https://github.com/timthelion)

runtime/container.go

@@ -364,14 +364,18 @@ func populateCommand(c *Container) {
 		driverConfig []string
 	)
 
+	en = &execdriver.Network{
+		Mtu:       c.runtime.config.Mtu,
+		Interface: nil,
+	}
+
 	if !c.Config.NetworkDisabled {
 		network := c.NetworkSettings
-		en = &execdriver.Network{
+		en.Interface = &execdriver.NetworkInterface{
 			Gateway:     network.Gateway,
 			Bridge:      network.Bridge,
 			IPAddress:   network.IPAddress,
 			IPPrefixLen: network.IPPrefixLen,
-			Mtu:         c.runtime.config.Mtu,
 		}
 	}
 

runtime/execdriver/driver.go

@@ -84,11 +84,15 @@ type Driver interface {
 
 // Network settings of the container
 type Network struct {
+	Interface *NetworkInterface `json:"interface"` // if interface is nil then networking is disabled
+	Mtu       int               `json:"mtu"`
+}
+
+type NetworkInterface struct {
 	Gateway     string `json:"gateway"`
 	IPAddress   string `json:"ip"`
 	Bridge      string `json:"bridge"`
 	IPPrefixLen int    `json:"ip_prefix_len"`
-	Mtu         int    `json:"mtu"`
 }
 
 type Resources struct {
@@ -118,8 +122,8 @@ type Command struct {
 	WorkingDir string     `json:"working_dir"`
 	ConfigPath string     `json:"config_path"` // this should be able to be removed when the lxc template is moved into the driver
 	Tty        bool       `json:"tty"`
-	Network    *Network   `json:"network"` // if network is nil then networking is disabled
-	Config     []string   `json:"config"`  //  generic values that specific drivers can consume
+	Network    *Network   `json:"network"`
+	Config     []string   `json:"config"` //  generic values that specific drivers can consume
 	Resources  *Resources `json:"resources"`
 	Mounts     []Mount    `json:"mounts"`
 

runtime/execdriver/lxc/driver.go

@@ -98,13 +98,15 @@ func (d *driver) Run(c *execdriver.Command, pipes *execdriver.Pipes, startCallba
 		DriverName,
 	}
 
-	if c.Network != nil {
+	if c.Network.Interface != nil {
 		params = append(params,
-			"-g", c.Network.Gateway,
-			"-i", fmt.Sprintf("%s/%d", c.Network.IPAddress, c.Network.IPPrefixLen),
-			"-mtu", strconv.Itoa(c.Network.Mtu),
+			"-g", c.Network.Interface.Gateway,
+			"-i", fmt.Sprintf("%s/%d", c.Network.Interface.IPAddress, c.Network.Interface.IPPrefixLen),
 		)
 	}
+	params = append(params,
+		"-mtu", strconv.Itoa(c.Network.Mtu),
+	)
 
 	if c.User != "" {
 		params = append(params, "-u", c.User)

runtime/execdriver/lxc/lxc_template.go

@@ -7,17 +7,17 @@ import (
 )
 
 const LxcTemplate = `
-{{if .Network}}
+{{if .Network.Interface}}
 # network configuration
 lxc.network.type = veth
-lxc.network.link = {{.Network.Bridge}}
+lxc.network.link = {{.Network.Interface.Bridge}}
 lxc.network.name = eth0
-lxc.network.mtu = {{.Network.Mtu}}
 {{else}}
 # network is disabled (-n=false)
 lxc.network.type = empty
 lxc.network.flags = up
 {{end}}
+lxc.network.mtu = {{.Network.Mtu}}
 
 # root filesystem
 {{$ROOTFS := .Rootfs}}

runtime/execdriver/lxc/lxc_template_unit_test.go

@@ -43,6 +43,10 @@ func TestLXCConfig(t *testing.T) {
 			Memory:    int64(mem),
 			CpuShares: int64(cpu),
 		},
+		Network: &execdriver.Network{
+			Mtu:       1500,
+			Interface: nil,
+		},
 	}
 	p, err := driver.generateLXCConfig(command)
 	if err != nil {
@@ -75,6 +79,10 @@ func TestCustomLxcConfig(t *testing.T) {
 			"lxc.utsname = docker",
 			"lxc.cgroup.cpuset.cpus = 0,1",
 		},
+		Network: &execdriver.Network{
+			Mtu:       1500,
+			Interface: nil,
+		},
 	}
 
 	p, err := driver.generateLXCConfig(command)

runtime/execdriver/native/default_template.go

@@ -20,11 +20,7 @@ func createContainer(c *execdriver.Command) *libcontainer.Container {
 	container.Env = c.Env
 
 	loopbackNetwork := libcontainer.Network{
-		// Using constants here because
-		// when networking is disabled
-		// These settings simply don't exist:
-		// https://github.com/dotcloud/docker/blob/c7ea6e5da80af3d9ba7558f876efbf0801d988d8/runtime/container.go#L367
-		Mtu:     1500,
+		Mtu:     c.Network.Mtu,
 		Address: fmt.Sprintf("%s/%d", "127.0.0.1", 0),
 		Gateway: "localhost",
 		Type:    "loopback",
@@ -35,15 +31,15 @@ func createContainer(c *execdriver.Command) *libcontainer.Container {
 		&loopbackNetwork,
 	}
 
-	if c.Network != nil {
+	if c.Network.Interface != nil {
 		vethNetwork := libcontainer.Network{
 			Mtu:     c.Network.Mtu,
-			Address: fmt.Sprintf("%s/%d", c.Network.IPAddress, c.Network.IPPrefixLen),
-			Gateway: c.Network.Gateway,
+			Address: fmt.Sprintf("%s/%d", c.Network.Interface.IPAddress, c.Network.Interface.IPPrefixLen),
+			Gateway: c.Network.Interface.Gateway,
 			Type:    "veth",
 			Context: libcontainer.Context{
 				"prefix": "veth",
-				"bridge": c.Network.Bridge,
+				"bridge": c.Network.Interface.Bridge,
 			},
 		}
 		container.Networks = append(container.Networks, &vethNetwork)