firstboot: generate netplan config rather than ifupdown

firstboot/firstboot.go

@@ -20,7 +20,6 @@
 package firstboot
 
 import (
-	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -46,38 +45,32 @@ func StampFirstBoot() error {
 	return osutil.AtomicWriteFile(dirs.SnapFirstBootStamp, []byte{}, 0644, 0)
 }
 
-var globs = []string{"/sys/class/net/eth*", "/sys/class/net/en*"}
-var ethdir = "/etc/network/interfaces.d"
-var ifup = "/sbin/ifup"
+var netplanConfigFile = "/etc/netplan/00-initial-config.yaml"
+var enableConfig = []string{"netplan", "apply"}
 
-func EnableFirstEther() error {
-	// ensure that udev is ready and we have the net stuff
-	if output, err := exec.Command("udevadm", "settle").CombinedOutput(); err != nil {
-		return osutil.OutputErr(output, err)
-	}
-
-	var eths []string
-	for _, glob := range globs {
-		eths, _ = filepath.Glob(glob)
-		if len(eths) != 0 {
-			break
-		}
-	}
-	if len(eths) == 0 {
-		return nil
-	}
-	eth := filepath.Base(eths[0])
-	ethfile := filepath.Join(ethdir, eth)
-	data := fmt.Sprintf("allow-hotplug %[1]s\niface %[1]s inet dhcp\n", eth)
+var netplanConfigData = `
+network:
+ version 2:
+  ethernets:
+   all:
+    match:
+     name: "*"
+    dhcp4: true
+`
 
-	if err := osutil.AtomicWriteFile(ethfile, []byte(data), 0644, 0); err != nil {
+// InitialNetworkConfig writes and applies a netplan config that
+// enables dhcp on all wired interfaces. In the long run this should
+// be run as part of the config-changed hook and read the snap's
+// config to determine the netplan config to write.
+func InitialNetworkConfig() error {
+	if err := osutil.AtomicWriteFile(netplanConfigFile, []byte(netplanConfigData), 0644, 0); err != nil {
 		return err
 	}
 
-	ifup := exec.Command(ifup, eth)
-	ifup.Stdout = os.Stdout
-	ifup.Stderr = os.Stderr
-	if err := ifup.Run(); err != nil {
+	enable := exec.Command(enableConfig[0], enableConfig[1:]...)
+	enable.Stdout = os.Stdout
+	enable.Stderr = os.Stderr
+	if err := enable.Run(); err != nil {
 		return err
 	}
 

firstboot/firstboot_test.go

@@ -22,24 +22,20 @@ package firstboot
 import (
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"testing"
 
 	. "gopkg.in/check.v1"
 
 	"github.com/snapcore/snapd/dirs"
-	"github.com/snapcore/snapd/testutil"
 )
 
 func TestStore(t *testing.T) { TestingT(t) }
 
 type FirstBootTestSuite struct {
-	globs  []string
-	ethdir string
-	ifup   string
-	e      error
-
-	udevadm *testutil.MockCmd
+	netplanConfigFile string
+	enableConfig      []string
 }
 
 var _ = Suite(&FirstBootTestSuite{})
@@ -48,53 +44,35 @@ func (s *FirstBootTestSuite) SetUpTest(c *C) {
 	tempdir := c.MkDir()
 	dirs.SetRootDir(tempdir)
 
-	s.globs = globs
-	globs = nil
-	s.ethdir = ethdir
-	ethdir = c.MkDir()
-	s.ifup = ifup
-	ifup = "/bin/true"
-
-	s.e = nil
-	s.udevadm = testutil.MockCommand(c, "udevadm", "")
+	s.netplanConfigFile = netplanConfigFile
+	netplanConfigFile = filepath.Join(c.MkDir(), "config.yaml")
+	s.enableConfig = enableConfig
+	enableConfig = []string{"/bin/true"}
 }
 
 func (s *FirstBootTestSuite) TearDownTest(c *C) {
-	globs = s.globs
-	ethdir = s.ethdir
-	ifup = s.ifup
-	s.udevadm.Restore()
-}
-
-func (s *FirstBootTestSuite) TestEnableFirstEther(c *C) {
-	c.Check(EnableFirstEther(), IsNil)
-	fs, _ := filepath.Glob(filepath.Join(ethdir, "*"))
-	c.Assert(fs, HasLen, 0)
+	netplanConfigFile = s.netplanConfigFile
+	enableConfig = s.enableConfig
 }
 
-func (s *FirstBootTestSuite) TestEnableFirstEtherSomeEth(c *C) {
-	dir := c.MkDir()
-	_, err := os.Create(filepath.Join(dir, "eth42"))
-	c.Assert(err, IsNil)
-
-	globs = []string{filepath.Join(dir, "eth*")}
-	c.Check(EnableFirstEther(), IsNil)
-	fs, _ := filepath.Glob(filepath.Join(ethdir, "*"))
-	c.Assert(fs, HasLen, 1)
-	bs, err := ioutil.ReadFile(fs[0])
+func (s *FirstBootTestSuite) TestInitialNetworkConfig(c *C) {
+	c.Check(InitialNetworkConfig(), IsNil)
+	bs, err := ioutil.ReadFile(netplanConfigFile)
 	c.Assert(err, IsNil)
-	c.Check(string(bs), Equals, "allow-hotplug eth42\niface eth42 inet dhcp\n")
-
+	c.Check(string(bs), Equals, netplanConfigData)
 }
 
-func (s *FirstBootTestSuite) TestEnableFirstEtherBadEthDir(c *C) {
-	dir := c.MkDir()
-	_, err := os.Create(filepath.Join(dir, "eth42"))
-	c.Assert(err, IsNil)
-
-	ethdir = "/no/such/thing"
-	globs = []string{filepath.Join(dir, "eth*")}
-	err = EnableFirstEther()
+func (s *FirstBootTestSuite) TestInitialNetworkConfigBadPath(c *C) {
+	netplanConfigFile = "/no/such/thing"
+	err := InitialNetworkConfig()
 	c.Check(err, NotNil)
 	c.Check(os.IsNotExist(err), Equals, true)
 }
+
+func (s *FirstBootTestSuite) TestInitialNetworkConfigEnableFails(c *C) {
+	enableConfig = []string{"/bin/false"}
+	err := InitialNetworkConfig()
+	c.Check(err, NotNil)
+	_, isExitError := err.(*exec.ExitError)
+	c.Check(isExitError, Equals, true)
+}

overlord/boot/firstboot.go

@@ -214,8 +214,8 @@ func FirstBoot() error {
 	if firstboot.HasRun() {
 		return ErrNotFirstBoot
 	}
-	if err := firstboot.EnableFirstEther(); err != nil {
-		logger.Noticef("Failed to bring up ethernet: %s", err)
+	if err := firstboot.InitialNetworkConfig(); err != nil {
+		logger.Noticef("Failed during inital network configuration: %s", err)
 	}
 
 	// snappy will be in a very unhappy state if this happens,