Add ability to perform an etcd on-demand snapshot via cli (#2819)

* add ability to perform an etcd on-demand snapshot via cli

(cherry picked from commit 13229019f8)
Signed-off-by: Brian Downs <brian.downs@gmail.com>

pkg/cli/cmds/etcd_snapshot.go

@@ -0,0 +1,39 @@
+package cmds
+
+import (
+	"github.com/rancher/k3s/pkg/version"
+	"github.com/urfave/cli"
+)
+
+const EtcdSnapshotCommand = "etcd-snapshot"
+
+func NewEtcdSnapshotCommand(action func(*cli.Context) error) cli.Command {
+	return cli.Command{
+		Name:            EtcdSnapshotCommand,
+		Usage:           "Trigger an immediate etcd snapshot",
+		SkipFlagParsing: false,
+		SkipArgReorder:  true,
+		Action:          action,
+		Flags: []cli.Flag{
+			DebugFlag,
+			LogFile,
+			AlsoLogToStderr,
+			cli.StringFlag{
+				Name:        "data-dir,d",
+				Usage:       "(data) Folder to hold state default /var/lib/rancher/" + version.Program + " or ${HOME}/.rancher/" + version.Program + " if not root",
+				Destination: &ServerConfig.DataDir,
+			},
+			&cli.StringFlag{
+				Name:        "name",
+				Usage:       "(db) Set the base name of the etcd on-demand snapshot (appended with UNIX timestamp).",
+				Destination: &ServerConfig.EtcdSnapshotName,
+				Value:       "on-demand",
+			},
+			&cli.StringFlag{
+				Name:        "dir",
+				Usage:       "(db) Directory to save etcd on-demand snapshot. (default: ${data-dir}/db/snapshots)",
+				Destination: &ServerConfig.EtcdSnapshotDir,
+			},
+		},
+	}
+}

pkg/cli/cmds/server.go

@@ -64,6 +64,7 @@ type Server struct {
 	ClusterResetRestorePath  string
 	EncryptSecrets           bool
 	StartupHooks             []func(context.Context, <-chan struct{}, string) error
+	EtcdSnapshotName         string
 	EtcdDisableSnapshots     bool
 	EtcdSnapshotDir          string
 	EtcdSnapshotCron         string
@@ -220,6 +221,12 @@ func NewServerCommand(action func(*cli.Context) error) cli.Command {
 				Usage:       "(db) Disable automatic etcd snapshots",
 				Destination: &ServerConfig.EtcdDisableSnapshots,
 			},
+			&cli.StringFlag{
+				Name:        "etcd-snapshot-name",
+				Usage:       "(db) Set the base name of etcd snapshots. Default: etcd-snapshot-<unix-timestamp>",
+				Destination: &ServerConfig.EtcdSnapshotName,
+				Value:       "etcd-snapshot",
+			},
 			&cli.StringFlag{
 				Name:        "etcd-snapshot-schedule-cron",
 				Usage:       "(db) Snapshot interval time in cron spec. eg. every 5 hours '* */5 * * *'",

pkg/cli/etcdsnapshot/etcd_snapshot.go

@@ -0,0 +1,62 @@
+package etcdsnapshot
+
+import (
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+
+	"github.com/erikdubbelboer/gspt"
+	"github.com/rancher/k3s/pkg/cli/cmds"
+	"github.com/rancher/k3s/pkg/cluster"
+	"github.com/rancher/k3s/pkg/daemons/config"
+	"github.com/rancher/k3s/pkg/etcd"
+	"github.com/rancher/k3s/pkg/server"
+	"github.com/rancher/wrangler/pkg/signals"
+	"github.com/urfave/cli"
+)
+
+func Run(app *cli.Context) error {
+	if err := cmds.InitLogging(); err != nil {
+		return err
+	}
+	return run(app, &cmds.ServerConfig)
+}
+
+func run(app *cli.Context, cfg *cmds.Server) error {
+	gspt.SetProcTitle(os.Args[0])
+
+	dataDir, err := server.ResolveDataDir(cfg.DataDir)
+	if err != nil {
+		return err
+	}
+
+	var serverConfig server.Config
+	serverConfig.DisableAgent = true
+	serverConfig.ControlConfig.DataDir = dataDir
+	serverConfig.ControlConfig.EtcdSnapshotName = cfg.EtcdSnapshotName
+	serverConfig.ControlConfig.EtcdSnapshotDir = cfg.EtcdSnapshotDir
+	serverConfig.ControlConfig.EtcdSnapshotRetention = 0 // disable retention check
+	serverConfig.ControlConfig.Runtime = &config.ControlRuntime{}
+	serverConfig.ControlConfig.Runtime.ETCDServerCA = filepath.Join(dataDir, "tls", "etcd", "server-ca.crt")
+	serverConfig.ControlConfig.Runtime.ClientETCDCert = filepath.Join(dataDir, "tls", "etcd", "client.crt")
+	serverConfig.ControlConfig.Runtime.ClientETCDKey = filepath.Join(dataDir, "tls", "etcd", "client.key")
+
+	ctx := signals.SetupSignalHandler(context.Background())
+
+	initialized, err := etcd.NewETCD().IsInitialized(ctx, &serverConfig.ControlConfig)
+	if err != nil {
+		return err
+	}
+	if !initialized {
+		return errors.New("managed etcd database has not been initialized")
+	}
+
+	cluster := cluster.New(&serverConfig.ControlConfig)
+
+	if err := cluster.Bootstrap(ctx); err != nil {
+		return err
+	}
+
+	return cluster.Snapshot(ctx, &serverConfig.ControlConfig)
+}

pkg/cli/server/server.go

@@ -127,6 +127,7 @@ func run(app *cli.Context, cfg *cmds.Server, leaderControllers server.CustomCont
 	serverConfig.ControlConfig.DisableControllerManager = cfg.DisableControllerManager
 	serverConfig.ControlConfig.ClusterInit = cfg.ClusterInit
 	serverConfig.ControlConfig.EncryptSecrets = cfg.EncryptSecrets
+	serverConfig.ControlConfig.EtcdSnapshotName = cfg.EtcdSnapshotName
 	serverConfig.ControlConfig.EtcdSnapshotCron = cfg.EtcdSnapshotCron
 	serverConfig.ControlConfig.EtcdSnapshotDir = cfg.EtcdSnapshotDir
 	serverConfig.ControlConfig.EtcdSnapshotRetention = cfg.EtcdSnapshotRetention