feat: implement apply configuration without reboot

This allows config to be written to disk without being applied
immediately.

Small refactoring to extract common code paths.

At first, I tried to implement this via the sequencer, but looks like
it's too hard to get it right, as sequencer lacks context and config to
be written is not applied to the runtime.

Fixes #2828

Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>

api/machine/machine.proto

@@ -61,7 +61,10 @@ service MachineService {
 // rpc applyConfiguration
 // ApplyConfiguration describes a request to assert a new configuration upon a
 // node.
-message ApplyConfigurationRequest { bytes data = 1; }
+message ApplyConfigurationRequest {
+  bytes data = 1;
+  bool no_reboot = 2;
+}
 
 // ApplyConfigurationResponse describes the response to a configuration request.
 message ApplyConfiguration { common.Metadata metadata = 1; }

cmd/talosctl/cmd/talos/apply-config.go

@@ -23,6 +23,7 @@ var applyConfigCmdFlags struct {
 	filename         string
 	insecure         bool
 	interactive      bool
+	noReboot         bool
 }
 
 // applyConfigCmd represents the applyConfiguration command.
@@ -109,6 +110,7 @@ var applyConfigCmd = &cobra.Command{
 
 			if _, err := c.ApplyConfiguration(ctx, &machineapi.ApplyConfigurationRequest{
 				Data:     cfgBytes,
+				NoReboot: applyConfigCmdFlags.noReboot,
 			}); err != nil {
 				return fmt.Errorf("error applying new configuration: %s", err)
 			}
@@ -122,7 +124,8 @@ func init() {
 	applyConfigCmd.Flags().StringVarP(&applyConfigCmdFlags.filename, "file", "f", "", "the filename of the updated configuration")
 	applyConfigCmd.Flags().BoolVarP(&applyConfigCmdFlags.insecure, "insecure", "i", false, "apply the config using the insecure (encrypted with no auth) maintenance service")
 	applyConfigCmd.Flags().StringSliceVar(&applyConfigCmdFlags.certFingerprints, "cert-fingerprint", nil, "list of server certificate fingeprints to accept (defaults to no check)")
-	applyConfigCmd.Flags().BoolVarP(&applyConfigCmdFlags.interactive, "interactive", "", false, "apply the config using text based interactive mode")
+	applyConfigCmd.Flags().BoolVar(&applyConfigCmdFlags.interactive, "interactive", false, "apply the config using text based interactive mode")
+	applyConfigCmd.Flags().BoolVar(&applyConfigCmdFlags.noReboot, "no-reboot", false, "apply the config only after the reboot")
 
 	addCommand(applyConfigCmd)
 }

internal/app/machined/internal/server/v1alpha1/v1alpha1_server.go

@@ -13,6 +13,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
@@ -93,6 +94,7 @@ func (s *Server) Register(obj *grpc.Server) {
 
 // ApplyConfiguration implements machine.MachineService.
 func (s *Server) ApplyConfiguration(ctx context.Context, in *machine.ApplyConfigurationRequest) (reply *machine.ApplyConfigurationResponse, err error) {
+	if !in.NoReboot {
 		if err = s.Controller.Runtime().SetConfig(in.GetData()); err != nil {
 			return nil, err
 		}
@@ -106,6 +108,28 @@ func (s *Server) ApplyConfiguration(ctx context.Context, in *machine.ApplyConfig
 				}
 			}
 		}()
+	} else {
+		cfg, err := s.Controller.Runtime().ValidateConfig(in.GetData())
+		if err != nil {
+			return nil, err
+		}
+
+		err = cfg.ApplyDynamicConfig(ctx, s.Controller.Runtime().State().Platform())
+		if err != nil {
+			return nil, err
+		}
+
+		var b []byte
+
+		b, err = cfg.Bytes()
+		if err != nil {
+			return nil, err
+		}
+
+		if err = ioutil.WriteFile(constants.ConfigPath, b, 0o600); err != nil {
+			return nil, err
+		}
+	}
 
 	reply = &machine.ApplyConfigurationResponse{
 		Messages: []*machine.ApplyConfiguration{

internal/app/machined/pkg/runtime/runtime.go

@@ -4,11 +4,14 @@
 
 package runtime
 
-import "github.com/talos-systems/talos/pkg/machinery/config"
+import (
+	"github.com/talos-systems/talos/pkg/machinery/config"
+)
 
 // Runtime defines the runtime parameters.
 type Runtime interface {
 	Config() config.Provider
+	ValidateConfig([]byte) (config.Provider, error)
 	SetConfig([]byte) error
 	State() State
 	Events() EventStream

internal/app/machined/pkg/runtime/v1alpha1/v1alpha1_runtime.go

@@ -35,15 +35,25 @@ func (r *Runtime) Config() config.Provider {
 	return r.c
 }
 
-// SetConfig implements the Runtime interface.
-func (r *Runtime) SetConfig(b []byte) error {
+// ValidateConfig implements the Runtime interface.
+func (r *Runtime) ValidateConfig(b []byte) (config.Provider, error) {
 	cfg, err := configloader.NewFromBytes(b)
 	if err != nil {
-		return fmt.Errorf("failed to parse config: %w", err)
+		return nil, fmt.Errorf("failed to parse config: %w", err)
 	}
 
 	if err := cfg.Validate(r.State().Platform().Mode()); err != nil {
-		return fmt.Errorf("failed to validate config: %w", err)
+		return nil, fmt.Errorf("failed to validate config: %w", err)
+	}
+
+	return cfg, nil
+}
+
+// SetConfig implements the Runtime interface.
+func (r *Runtime) SetConfig(b []byte) error {
+	cfg, err := r.ValidateConfig(b)
+	if err != nil {
+		return err
 	}
 
 	r.c = cfg

internal/app/machined/pkg/runtime/v1alpha1/v1alpha1_sequencer.go

@@ -58,8 +58,9 @@ func (*Sequencer) ApplyConfiguration(r runtime.Runtime, req *machineapi.ApplyCon
 	).Append(
 		"unmountState",
 		UnmountStatePartition,
-	).AppendList(stopAllPhaselist(r)).
-		Append(
+	).AppendList(
+		stopAllPhaselist(r),
+	).Append(
 		"reboot",
 		Reboot,
 	)

internal/app/machined/pkg/runtime/v1alpha1/v1alpha1_sequencer_tasks.go

@@ -485,31 +485,10 @@ func LoadConfig(seq runtime.Sequence, data interface{}) (runtime.TaskExecutionFu
 // SaveConfig represents the SaveConfig task.
 func SaveConfig(seq runtime.Sequence, data interface{}) (runtime.TaskExecutionFunc, string) {
 	return func(ctx context.Context, logger *log.Logger, r runtime.Runtime) (err error) {
-		saveCtx, ctxCancel := context.WithTimeout(context.Background(), 30*time.Second)
-		defer ctxCancel()
-
-		hostname, err := r.State().Platform().Hostname(saveCtx)
-		if err != nil {
+		if err = r.Config().ApplyDynamicConfig(ctx, r.State().Platform()); err != nil {
 			return err
 		}
 
-		if hostname != nil {
-			r.Config().Machine().Network().SetHostname(string(hostname))
-		}
-
-		addrs, err := r.State().Platform().ExternalIPs(saveCtx)
-		if err != nil {
-			logger.Printf("certificates will be created without external IPs: %v", err)
-		}
-
-		sans := make([]string, 0, len(addrs))
-		for _, addr := range addrs {
-			sans = append(sans, addr.String())
-		}
-
-		r.Config().Machine().Security().SetCertSANs(sans)
-		r.Config().Cluster().SetCertSANs(sans)
-
 		var b []byte
 
 		b, err = r.Config().Bytes()

internal/app/maintenance/server/server.go

@@ -49,6 +49,10 @@ func (s *Server) Register(obj *grpc.Server) {
 
 // ApplyConfiguration implements machine.MachineService.
 func (s *Server) ApplyConfiguration(ctx context.Context, in *machine.ApplyConfigurationRequest) (reply *machine.ApplyConfigurationResponse, err error) {
+	if in.NoReboot {
+		return nil, fmt.Errorf("apply configuration without reboot is not supported in maintenance mode")
+	}
+
 	cfgProvider, err := configloader.NewFromBytes(in.GetData())
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse config: %w", err)

internal/app/networkd/pkg/networkd/networkd_test.go

@@ -72,7 +72,7 @@ func (suite *NetworkdSuite) TestHostname() {
 	suite.Assert().Equal(addr, net.ParseIP("192.168.0.10"))
 
 	// Static for computed hostname ( talos-ip )
-	sampleConfig.Machine().Network().SetHostname("")
+	sampleConfig.(*v1alpha1.Config).MachineConfig.MachineNetwork.NetworkHostname = ""
 
 	nwd, err = New(sampleConfig)
 	suite.Require().NoError(err)
@@ -83,7 +83,7 @@ func (suite *NetworkdSuite) TestHostname() {
 	suite.Assert().Equal(addr, net.ParseIP("192.168.0.10"))
 
 	// Static for hostname too long
-	sampleConfig.Machine().Network().SetHostname("somereallyreallyreallylongstringthathasmorethan63charactersbecauseweneedtotestit")
+	sampleConfig.(*v1alpha1.Config).MachineConfig.MachineNetwork.NetworkHostname = "somereallyreallyreallylongstringthathasmorethan63charactersbecauseweneedtotestit"
 
 	nwd, err = New(sampleConfig)
 	suite.Require().NoError(err)
@@ -93,7 +93,7 @@ func (suite *NetworkdSuite) TestHostname() {
 	suite.Require().Error(err)
 
 	// Static for hostname vs domain name
-	sampleConfig.Machine().Network().SetHostname("dadjokes.biz.dev.com.org.io")
+	sampleConfig.(*v1alpha1.Config).MachineConfig.MachineNetwork.NetworkHostname = "dadjokes.biz.dev.com.org.io"
 
 	nwd, err = New(sampleConfig)
 	suite.Require().NoError(err)

internal/integration/api/apply-config.go

@@ -40,6 +40,10 @@ const applyConfigTestSysctl = "net.ipv6.conf.all.accept_ra_mtu"
 
 const applyConfigTestSysctlVal = "1"
 
+const applyConfigNoRebootTestSysctl = "fs.file-max"
+
+const applyConfigNoRebootTestSysctlVal = "500000"
+
 const assertRebootedRebootTimeout = 10 * time.Minute
 
 // ApplyConfigSuite ...
@@ -127,6 +131,52 @@ func (suite *ApplyConfigSuite) TestApply() {
 	)
 }
 
+// TestApplyNoReboot verifies the apply config API without reboot.
+func (suite *ApplyConfigSuite) TestApplyNoReboot() {
+	suite.WaitForBootDone(suite.ctx)
+
+	node := suite.RandomDiscoveredNode()
+	nodeCtx := client.WithNodes(suite.ctx, node)
+
+	provider, err := suite.readConfigFromNode(nodeCtx)
+	suite.Require().NoError(err, "failed to read existing config from node %q", node)
+
+	provider.Machine().Sysctls()[applyConfigNoRebootTestSysctl] = applyConfigNoRebootTestSysctlVal
+
+	cfgDataOut, err := provider.Bytes()
+	suite.Require().NoError(err, "failed to marshal updated machine config data (node %q)", node)
+
+	_, err = suite.Client.ApplyConfiguration(nodeCtx, &machineapi.ApplyConfigurationRequest{
+		NoReboot: true,
+		Data:     cfgDataOut,
+	})
+	suite.Require().NoError(err, "failed to apply deferred configuration (node %q): %w", node)
+
+	// Verify configuration change
+	var newProvider config.Provider
+
+	newProvider, err = suite.readConfigFromNode(nodeCtx)
+
+	suite.Require().NoError(err, "failed to read updated configuration from node %q: %w", node)
+
+	suite.Assert().Equal(
+		newProvider.Machine().Sysctls()[applyConfigNoRebootTestSysctl],
+		applyConfigNoRebootTestSysctlVal,
+	)
+
+	// revert back
+	delete(provider.Machine().Sysctls(), applyConfigNoRebootTestSysctl)
+
+	cfgDataOut, err = provider.Bytes()
+	suite.Require().NoError(err, "failed to marshal updated machine config data (node %q)", node)
+
+	_, err = suite.Client.ApplyConfiguration(nodeCtx, &machineapi.ApplyConfigurationRequest{
+		NoReboot: true,
+		Data:     cfgDataOut,
+	})
+	suite.Require().NoError(err, "failed to apply deferred configuration (node %q): %w", node)
+}
+
 func (suite *ApplyConfigSuite) readConfigFromNode(nodeCtx context.Context) (config.Provider, error) {
 	// Load the current node machine config
 	cfgData := new(bytes.Buffer)

pkg/machinery/config/dynamic.go

@@ -0,0 +1,16 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package config
+
+import (
+	"context"
+	"net"
+)
+
+// DynamicConfigProvider provides additional configuration which is overlaid on top of existing configuration.
+type DynamicConfigProvider interface {
+	Hostname(context.Context) ([]byte, error)
+	ExternalIPs(context.Context) ([]net.IP, error)
+}

pkg/machinery/config/provider.go

@@ -5,6 +5,7 @@
 package config
 
 import (
+	"context"
 	"crypto/tls"
 	"net/url"
 	"os"
@@ -24,6 +25,7 @@ type Provider interface {
 	Machine() MachineConfig
 	Cluster() ClusterConfig
 	Validate(RuntimeMode) error
+	ApplyDynamicConfig(context.Context, DynamicConfigProvider) error
 	String() (string, error)
 	Bytes() ([]byte, error)
 }
@@ -84,14 +86,12 @@ type Security interface {
 	CA() *x509.PEMEncodedCertificateAndKey
 	Token() string
 	CertSANs() []string
-	SetCertSANs([]string)
 }
 
 // MachineNetwork defines the requirements for a config that pertains to network
 // related options.
 type MachineNetwork interface {
 	Hostname() string
-	SetHostname(string)
 	Resolvers() []string
 	Devices() []Device
 	ExtraHosts() []ExtraHost
@@ -230,7 +230,6 @@ type ClusterConfig interface {
 	Endpoint() *url.URL
 	Token() Token
 	CertSANs() []string
-	SetCertSANs([]string)
 	CA() *x509.PEMEncodedCertificateAndKey
 	AESCBCEncryptionSecret() string
 	Config(machine.Type) (string, error)

pkg/machinery/config/types/v1alpha1/v1alpha1_provider.go

@@ -5,9 +5,11 @@
 package v1alpha1
 
 import (
+	"context"
 	"crypto/tls"
 	stdx509 "crypto/x509"
 	"fmt"
+	"log"
 	"net/url"
 	"os"
 	goruntime "runtime"
@@ -70,6 +72,53 @@ func (c *Config) Bytes() (res []byte, err error) {
 	return
 }
 
+// ApplyDynamicConfig implements the config.Provider interface.
+func (c *Config) ApplyDynamicConfig(ctx context.Context, dynamicProvider config.DynamicConfigProvider) error {
+	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+
+	if c.MachineConfig == nil {
+		c.MachineConfig = &MachineConfig{}
+	}
+
+	hostname, err := dynamicProvider.Hostname(ctx)
+	if err != nil {
+		return err
+	}
+
+	if hostname != nil {
+		if c.MachineConfig.MachineNetwork == nil {
+			c.MachineConfig.MachineNetwork = &NetworkConfig{}
+		}
+
+		c.MachineConfig.MachineNetwork.NetworkHostname = string(hostname)
+	}
+
+	addrs, err := dynamicProvider.ExternalIPs(ctx)
+	if err != nil {
+		log.Printf("certificates will be created without external IPs: %v", err)
+	}
+
+	sans := make([]string, 0, len(addrs))
+	for _, addr := range addrs {
+		sans = append(sans, addr.String())
+	}
+
+	c.MachineConfig.MachineCertSANs = append(c.MachineConfig.MachineCertSANs, sans...)
+
+	if c.ClusterConfig == nil {
+		c.ClusterConfig = &ClusterConfig{}
+	}
+
+	if c.ClusterConfig.APIServerConfig == nil {
+		c.ClusterConfig.APIServerConfig = &APIServerConfig{}
+	}
+
+	c.ClusterConfig.APIServerConfig.CertSANs = append(c.ClusterConfig.APIServerConfig.CertSANs, sans...)
+
+	return nil
+}
+
 // Install implements the config.Provider interface.
 func (m *MachineConfig) Install() config.Install {
 	if m.MachineInstall == nil {
@@ -179,11 +228,6 @@ func (m *MachineConfig) CertSANs() []string {
 	return m.MachineCertSANs
 }
 
-// SetCertSANs implements the config.Provider interface.
-func (m *MachineConfig) SetCertSANs(sans []string) {
-	m.MachineCertSANs = append(m.MachineCertSANs, sans...)
-}
-
 // Registries implements the config.Provider interface.
 func (m *MachineConfig) Registries() config.Registries {
 	return &m.MachineRegistries
@@ -242,15 +286,6 @@ func (c *ClusterConfig) CertSANs() []string {
 	return c.APIServerConfig.CertSANs
 }
 
-// SetCertSANs implements the config.Provider interface.
-func (c *ClusterConfig) SetCertSANs(sans []string) {
-	if c.APIServerConfig == nil {
-		c.APIServerConfig = &APIServerConfig{}
-	}
-
-	c.APIServerConfig.CertSANs = append(c.APIServerConfig.CertSANs, sans...)
-}
-
 // CA implements the config.Provider interface.
 func (c *ClusterConfig) CA() *x509.PEMEncodedCertificateAndKey {
 	return c.ClusterCA
@@ -641,11 +676,6 @@ func (n *NetworkConfig) Hostname() string {
 	return n.NetworkHostname
 }
 
-// SetHostname implements the config.Provider interface.
-func (n *NetworkConfig) SetHostname(hostname string) {
-	n.NetworkHostname = hostname
-}
-
 // Devices implements the config.Provider interface.
 func (n *NetworkConfig) Devices() []config.Device {
 	interfaces := make([]config.Device, len(n.NetworkInterfaces))

website/content/docs/v0.7/Reference/api.md

@@ -344,6 +344,7 @@ node.
 | Field | Type | Label | Description |
 | ----- | ---- | ----- | ----------- |
 | data | [bytes](#bytes) |  |  |
+| no_reboot | [bool](#bool) |  |  |
 
 
 

website/content/docs/v0.7/Reference/cli.md

@@ -20,6 +20,7 @@ talosctl apply-config [flags]
   -h, --help                       help for apply-config
   -i, --insecure                   apply the config using the insecure (encrypted with no auth) maintenance service
       --interactive                apply the config using text based interactive mode
+      --no-reboot                  apply the config only after the reboot
 ```
 
 ### Options inherited from parent commands