Add ability to set hostname via DHCP during install

pkg/console/constant.go

@@ -83,4 +83,6 @@ const (
 	persistentSizeNote     = "Note: persistent partition stores data like system package and container images, not the VM data. \nYou can specify a size like 200Gi or 153600Mi. \nLeave it blank to use the default value."
 
 	authorizedFile = "/home/rancher/.ssh/authorized_keys"
+
+	defaultHostname = "rancher"
 )

pkg/console/install_panels.go

@@ -506,7 +506,7 @@ func addDiskPanel(c *Console) error {
 		if installModeOnly {
 			return showNext(c, passwordConfirmPanel, passwordPanel)
 		}
-		return showHostnamePage(c)
+		return showNetworkPage(c)
 	}
 
 	diskConfirm := func(_ *gocui.Gui, _ *gocui.View) error {
@@ -840,7 +840,7 @@ func addAskCreatePanel(c *Console) error {
 				return showRolePage(c)
 			}
 			if alreadyInstalled {
-				return showHostnamePage(c)
+				return showNetworkPage(c)
 			}
 			return showDiskPage(c)
 		},
@@ -898,7 +898,7 @@ func addAskRolePanel(c *Console) error {
 			c.config.Install.Role = selected
 			askRoleV.Close()
 			if alreadyInstalled {
-				return showHostnamePage(c)
+				return showNetworkPage(c)
 			}
 			return showDiskPage(c)
 		},
@@ -1199,20 +1199,18 @@ func addHostnamePanel(c *Console) error {
 		return c.setContentByName(hostnameValidatorPanel, message)
 	}
 
+	getNextPagePanel := func() []string {
+		return []string{dnsServersPanel}
+	}
+
 	next := func() error {
 		c.CloseElements(hostnamePanel, hostnameValidatorPanel)
-		return showNetworkPage(c)
+		return showNext(c, getNextPagePanel()...)
 	}
 
 	prev := func(_ *gocui.Gui, _ *gocui.View) error {
 		c.CloseElements(hostnamePanel, hostnameValidatorPanel)
-		if alreadyInstalled {
-			if c.config.Install.Mode == config.ModeJoin {
-				return showNext(c, askRolePanel)
-			}
-			return showNext(c, askCreatePanel)
-		}
-		return showDiskPage(c)
+		return showNetworkPage(c)
 	}
 
 	validate := func() (string, error) {
@@ -1234,6 +1232,10 @@ func addHostnamePanel(c *Console) error {
 
 	hostnameV.PreShow = func() error {
 		c.Gui.Cursor = true
+		// On the first run through the interactive installer, the hostname is
+		// not yet set in the harvester config, but we might have been given
+		// a new hostname via DHCP...
+		checkDHCPHostname(c.config, false)
 		hostnameV.Value = c.config.Hostname
 		return c.setContentByName(titlePanel, hostnameTitle)
 	}
@@ -1391,10 +1393,6 @@ func addNetworkPanel(c *Console) error {
 		return "", nil
 	}
 
-	getNextPagePanel := func() []string {
-		return []string{dnsServersPanel}
-	}
-
 	gotoNextPage := func(fromPanel string) error {
 		if err := networkValidatorV.Show(); err != nil {
 			return err
@@ -1421,7 +1419,7 @@ func addNetworkPanel(c *Console) error {
 				spinner.Stop(false, "")
 				g.Update(func(_ *gocui.Gui) error {
 					closeThisPage()
-					return showNext(c, getNextPagePanel()...)
+					return showHostnamePage(c)
 				})
 			}
 		}(c.Gui)
@@ -1430,7 +1428,13 @@ func addNetworkPanel(c *Console) error {
 
 	gotoPrevPage := func(_ *gocui.Gui, _ *gocui.View) error {
 		closeThisPage()
-		return showHostnamePage(c)
+		if alreadyInstalled {
+			if c.config.Install.Mode == config.ModeJoin {
+				return showNext(c, askRolePanel)
+			}
+			return showNext(c, askCreatePanel)
+		}
+		return showDiskPage(c)
 	}
 	// askInterfaceV
 	askInterfaceV.PreShow = func() error {
@@ -2016,6 +2020,8 @@ func addInstallPanel(c *Console) error {
 			if alreadyInstalled && c.config.Automatic == true && c.config.ManagementInterface.Method == "dhcp" {
 				configureInstallModeDHCP(c)
 			}
+
+			// Need to merge remote config first
 			logrus.Info("Local config: ", c.config)
 			if c.config.Install.ConfigURL != "" {
 				printToPanel(c.Gui, fmt.Sprintf("Fetching %s...", c.config.Install.ConfigURL), installPanel)
@@ -2031,28 +2037,50 @@ func addInstallPanel(c *Console) error {
 					return
 				}
 				logrus.Info("Local config (merged): ", c.config)
+			}
 
-				if needToGetVIPFromDHCP(c.config.VipMode, c.config.Vip, c.config.VipHwAddr) {
-					printToPanel(c.Gui, "Configuring network...", installPanel)
-					if _, err := applyNetworks(c.config.ManagementInterface, c.config.Hostname); err != nil {
-						printToPanel(c.Gui, fmt.Sprintf("can't apply networks: %s", err), installPanel)
-						return
-					}
-					mgmtName := getManagementInterfaceName(c.config.ManagementInterface)
-					vip, err := getVipThroughDHCP(mgmtName)
-					if err != nil {
-						printToPanel(c.Gui, fmt.Sprintf("fail to get vip: %s", err), installPanel)
-						return
-					}
-					c.config.Vip = vip.ipv4Addr
-					c.config.VipHwAddr = vip.hwAddr
+			// case insensitive for network method and vip mode
+			c.config.ManagementInterface.Method = strings.ToLower(c.config.ManagementInterface.Method)
+			c.config.VipMode = strings.ToLower(c.config.VipMode)
+
+			// lookup MAC Address to populate device names where needed
+			// lookup device name to populate MAC Address
+			// This needs to happen early, before a possible call to
+			// applyNetworks() in the DHCP case.
+			for i := range c.config.ManagementInterface.Interfaces {
+				if err := c.config.ManagementInterface.Interfaces[i].FindNetworkInterfaceNameAndHwAddr(); err != nil {
+					logrus.Error(err)
+					printToPanel(c.Gui, err.Error(), installPanel)
+					return
+				}
+			}
+
+			if c.config.Automatic && c.config.Install.ManagementInterface.Method == config.NetworkMethodDHCP {
+				// Only need to do this for automatic installs, as manual installs will
+				// have already run applyNetworks()
+				printToPanel(c.Gui, "Configuring network...", installPanel)
+				if output, err := applyNetworks(c.config.ManagementInterface, c.config.Hostname); err != nil {
+					printToPanel(c.Gui, fmt.Sprintf("Can't apply networks: %s\n%s", err, string(output)), installPanel)
+					return
 				}
 			}
-			c.config.VipMode = strings.ToLower(c.config.VipMode)
 
-			if c.config.Hostname == "" {
-				c.config.Hostname = generateHostName()
+			if needToGetVIPFromDHCP(c.config.VipMode, c.config.Vip, c.config.VipHwAddr) {
+				mgmtName := getManagementInterfaceName(c.config.ManagementInterface)
+				vip, err := getVipThroughDHCP(mgmtName)
+				if err != nil {
+					printToPanel(c.Gui, fmt.Sprintf("fail to get vip: %s", err), installPanel)
+					return
+				}
+				c.config.Vip = vip.ipv4Addr
+				c.config.VipHwAddr = vip.hwAddr
 			}
+
+			// If no hostname was provided in the config, this function will
+			// default the hostname to either what's supplied by the DHCP sever,
+			// or a randomly generated name.
+			checkDHCPHostname(c.config, true)
+
 			if c.config.TTY == "" {
 				c.config.TTY = getFirstConsoleTTY()
 			}
@@ -2065,19 +2093,6 @@ func addInstallPanel(c *Console) error {
 				c.config.ServerURL = formatted
 			}
 
-			// lookup MAC Address to populate device names where needed
-			// lookup device name to populate MAC Address
-			tmpInterfaces := []config.NetworkInterface{}
-			for _, iface := range c.config.ManagementInterface.Interfaces {
-				if err := iface.FindNetworkInterfaceNameAndHwAddr(); err != nil {
-					logrus.Error(err)
-					printToPanel(c.Gui, err.Error(), installPanel)
-					return
-				}
-				tmpInterfaces = append(tmpInterfaces, iface)
-			}
-			c.config.ManagementInterface.Interfaces = tmpInterfaces
-
 			if !alreadyInstalled {
 				// Have to handle preflight warnings here because we can't check
 				// the NIC speed until we've got the correct set of interfaces.
@@ -2111,9 +2126,6 @@ func addInstallPanel(c *Console) error {
 				c.config.DataDisk = ""
 			}
 
-			// case insensitive for network method and vip mode
-			c.config.ManagementInterface.Method = strings.ToLower(c.config.ManagementInterface.Method)
-
 			if err := validateConfig(ConfigValidator{}, c.config); err != nil {
 				printToPanel(c.Gui, err.Error(), installPanel)
 				return
@@ -2434,7 +2446,7 @@ func addDNSServersPanel(c *Console) error {
 	}
 	gotoPrevPage := func(_ *gocui.Gui, _ *gocui.View) error {
 		closeThisPage()
-		return showNetworkPage(c)
+		return showHostnamePage(c)
 	}
 	gotoNextPage := func() error {
 		closeThisPage()
@@ -2560,6 +2572,23 @@ func configureInstallModeDHCP(c *Console) {
 
 }
 
+func checkDHCPHostname(c *config.HarvesterConfig, generate bool) {
+	if c.Hostname == "" {
+		hostname, err := os.Hostname()
+		if err != nil {
+			logrus.Errorf("error fetching hostname from underlying OS: %v", err)
+		}
+
+		if hostname != defaultHostname && hostname != "" {
+			c.Hostname = hostname
+		} else {
+			if generate {
+				c.Hostname = generateHostName()
+			}
+		}
+	}
+}
+
 func mergeCloudInit(c *config.HarvesterConfig) error {
 	cloudConfig, err := config.ReadUserDataConfig()
 	if err != nil {

pkg/console/network.go

@@ -24,6 +24,29 @@ func applyNetworks(network config.Network, hostname string) ([]byte, error) {
 		return nil, err
 	}
 
+	// If called without a hostname set, we enable setting hostname via the
+	// DHCP server, in case the DHCP server is configured to give us a
+	// hostname we can use by default.
+	//
+	// If we move the network interface page of the installer so it's before
+	// the hostname page, this function will activate once the management
+	// NIC is configured, and if the DHCP server is configured correctly,
+	// the system hostname will be set to the one provided by the server.
+	// Later, on the hostname page, we can default the hostname field to
+	// the current system hostname.
+
+	dhclientSetHostname := "no"
+	if hostname == "" {
+		dhclientSetHostname = "yes"
+	}
+	output, err := exec.Command("sed", "-i",
+		fmt.Sprintf(`s/^DHCLIENT_SET_HOSTNAME=.*/DHCLIENT_SET_HOSTNAME="%s"/`, dhclientSetHostname),
+		"/etc/sysconfig/network/dhcp").CombinedOutput()
+	if err != nil {
+		logrus.Error(err, string(output))
+		return output, err
+	}
+
 	conf := &yipSchema.YipConfig{
 		Name: "Network Configuration",
 		Stages: map[string][]yipSchema.Stage{
@@ -33,7 +56,7 @@ func applyNetworks(network config.Network, hostname string) ([]byte, error) {
 			},
 		},
 	}
-	_, err := config.UpdateManagementInterfaceConfig(&conf.Stages["live"][1], network, true)
+	_, err = config.UpdateManagementInterfaceConfig(&conf.Stages["live"][1], network, true)
 	if err != nil {
 		return nil, err
 	}
@@ -56,6 +79,10 @@ func applyNetworks(network config.Network, hostname string) ([]byte, error) {
 	cmd := exec.Command("/usr/bin/yip", "-s", "live", tempFile.Name())
 	cmd.Env = os.Environ()
 	bytes, err = cmd.CombinedOutput()
+	if err != nil {
+		logrus.Error(err, string(bytes))
+		return bytes, err
+	}
 	// Restore Down NIC to up
 	if err := upAllLinks(); err != nil {
 		logrus.Errorf("failed to bring all link up: %s", err.Error())