component/snapshots: Create new component

This commit creates a new 'snapshots' component that is intended to
manage snapshots and backups.

cmd/backup.go

@@ -53,7 +53,7 @@ func (bk backupC) Run(context wisski_distillery.Context) error {
 	if !bk.StagingOnly {
 		// regular mode: create a temporary staging directory
 		logging.LogMessage(context.IOStream, "Creating new snapshot staging directory")
-		sPath, err = dis.NewSnapshotStagingDir("")
+		sPath, err = dis.Snapshots().NewStagingDir("")
 		if err != nil {
 			return errSnapshotFailed.Wrap(err)
 		}
@@ -65,7 +65,7 @@ func (bk backupC) Run(context wisski_distillery.Context) error {
 		// staging mode: use dest as a destination
 		sPath = bk.Positionals.Dest
 		if sPath == "" {
-			sPath, err = dis.NewSnapshotStagingDir("")
+			sPath, err = dis.Snapshots().NewStagingDir("")
 			if err != nil {
 				return errSnapshotFailed.Wrap(err)
 			}
@@ -100,7 +100,7 @@ func (bk backupC) Run(context wisski_distillery.Context) error {
 	// create the archive path
 	archivePath := bk.Positionals.Dest
 	if archivePath == "" {
-		archivePath = dis.NewSnapshotArchivePath("")
+		archivePath = dis.Snapshots().NewArchivePath("")
 	}
 
 	// and write everything into it!

cmd/snapshot.go

@@ -55,7 +55,7 @@ func (bi snapshot) Run(context wisski_distillery.Context) error {
 	if !bi.StagingOnly {
 		// regular mode: create a temporary staging directory
 		logging.LogMessage(context.IOStream, "Creating new snapshot staging directory")
-		sPath, err = dis.NewSnapshotStagingDir(instance.Slug)
+		sPath, err = dis.Snapshots().NewStagingDir(instance.Slug)
 		if err != nil {
 			return errSnapshotFailed.Wrap(err)
 		}
@@ -67,7 +67,7 @@ func (bi snapshot) Run(context wisski_distillery.Context) error {
 		// staging mode: use dest as a destination
 		sPath = bi.Positionals.Dest
 		if sPath == "" {
-			sPath, err = dis.NewSnapshotStagingDir(instance.Slug)
+			sPath, err = dis.Snapshots().NewStagingDir(instance.Slug)
 			if err != nil {
 				return errSnapshotFailed.Wrap(err)
 			}
@@ -107,7 +107,7 @@ func (bi snapshot) Run(context wisski_distillery.Context) error {
 	// create the archive path
 	archivePath := bi.Positionals.Dest
 	if archivePath == "" {
-		archivePath = dis.NewSnapshotArchivePath(instance.Slug)
+		archivePath = dis.Snapshots().NewArchivePath(instance.Slug)
 	}
 
 	// and write everything into it!

cmd/system_update.go

@@ -70,8 +70,8 @@ func (si systemupdate) Run(context wisski_distillery.Context) error {
 	for _, d := range []string{
 		dis.Config.DeployRoot,
 		dis.Instances().Path(),
-		dis.SnapshotsStagingPath(),
+		dis.Snapshots().StagingPath(),
-		dis.SnapshotsArchivePath(),
+		dis.Snapshots().ArchivePath(),
 	} {
 		context.Println(d)
 		if err := dis.Core.Environment.MkdirAll(d, environment.DefaultDirPerm); err != nil {

internal/component/snapshots/snapshots.go

@@ -0,0 +1,72 @@
+package snapshots
+
+import (
+	"fmt"
+	"path/filepath"
+	"time"
+
+	"github.com/FAU-CDI/wisski-distillery/internal/component"
+	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
+	"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
+	"github.com/FAU-CDI/wisski-distillery/pkg/password"
+)
+
+// Snapshots manages snapshots and backups
+type Snapshots struct {
+	component.ComponentBase
+}
+
+func (Snapshots) Name() string { return "snapshots" }
+
+// Path returns the path that contains all snapshot related data.
+func (dis *Snapshots) Path() string {
+	return filepath.Join(dis.Config.DeployRoot, "snapshots")
+}
+
+// StagingPath returns the path to the directory containing a temporary staging area for snapshots.
+// Use NewSnapshotStagingDir to generate a new staging area.
+func (dis *Snapshots) StagingPath() string {
+	return filepath.Join(dis.Path(), "staging")
+}
+
+// ArchivePath returns the path to the directory containing all exported archives.
+// Use NewSnapshotArchivePath to generate a path to a new archive in this directory.
+func (dis *Snapshots) ArchivePath() string {
+	return filepath.Join(dis.Path(), "archives")
+}
+
+// NewArchivePath returns the path to a new archive with the provided prefix.
+// The path is guaranteed to not exist.
+func (dis *Snapshots) NewArchivePath(prefix string) (path string) {
+	// TODO: Consider moving these into a subdirectory with the provided prefix.
+	for path == "" || fsx.Exists(dis.Environment, path) {
+		name := dis.newSnapshotName(prefix) + ".tar.gz"
+		path = filepath.Join(dis.ArchivePath(), name)
+	}
+	return
+}
+
+// newSnapshot name returns a new basename for a snapshot with the provided prefix.
+// The name is guaranteed to be unique within this process.
+func (*Snapshots) newSnapshotName(prefix string) string {
+	suffix, _ := password.Password(64) // silently ignore any errors!
+	if prefix == "" {
+		prefix = "backup"
+	} else {
+		prefix = "snapshot-" + prefix
+	}
+	return fmt.Sprintf("%s-%d-%s", prefix, time.Now().Unix(), suffix)
+}
+
+// NewStagingDir returns the path to a new snapshot directory.
+// The directory is guaranteed to have been freshly created.
+func (dis *Snapshots) NewStagingDir(prefix string) (path string, err error) {
+	for path == "" || environment.IsExist(err) {
+		path = filepath.Join(dis.StagingPath(), dis.newSnapshotName(prefix))
+		err = dis.Core.Environment.Mkdir(path, environment.DefaultFilePerm)
+	}
+	if err != nil {
+		path = ""
+	}
+	return
+}

internal/wisski/backup_prune.go

@@ -14,7 +14,7 @@ func (dis *Distillery) ShouldPrune(modtime time.Time) bool {
 
 // PruneBackups prunes all backups older than the maximum backup age
 func (dis *Distillery) PruneBackups(io stream.IOStream) error {
-	sPath := dis.SnapshotsArchivePath()
+	sPath := dis.Snapshots().ArchivePath()
 
 	// list all the files
 	entries, err := dis.Core.Environment.ReadDir(sPath)

internal/wisski/component.go

@@ -6,6 +6,7 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/internal/component"
 	"github.com/FAU-CDI/wisski-distillery/internal/component/control"
 	"github.com/FAU-CDI/wisski-distillery/internal/component/instances"
+	"github.com/FAU-CDI/wisski-distillery/internal/component/snapshots"
 	"github.com/FAU-CDI/wisski-distillery/internal/component/sql"
 	"github.com/FAU-CDI/wisski-distillery/internal/component/ssh"
 	"github.com/FAU-CDI/wisski-distillery/internal/component/triplestore"
@@ -29,6 +30,7 @@ type components struct {
 
 	// other components
 	instances lazy.Lazy[*instances.Instances]
+	snapshots lazy.Lazy[*snapshots.Snapshots]
 }
 
 //
@@ -73,6 +75,12 @@ func (dis *Distillery) Instances() *instances.Instances {
 	})
 }
 
+func (dis *Distillery) Snapshots() *snapshots.Snapshots {
+	return component.Initialize(dis.Core, &dis.components.snapshots, func(snapshots *snapshots.Snapshots) {
+
+	})
+}
+
 //
 // ALL COMPONENTS
 //

internal/wisski/snapshot.go

@@ -15,65 +15,11 @@ import (
 	"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
 	"github.com/FAU-CDI/wisski-distillery/pkg/logging"
 	"github.com/FAU-CDI/wisski-distillery/pkg/opgroup"
-	"github.com/FAU-CDI/wisski-distillery/pkg/password"
 	"github.com/tkw1536/goprogram/status"
 	"github.com/tkw1536/goprogram/stream"
 	"golang.org/x/exp/slices"
 )
 
-// SnapshotsDir returns the path that contains all snapshot related data.
-func (dis *Distillery) SnapshotsDir() string {
-	return filepath.Join(dis.Config.DeployRoot, "snapshots")
-}
-
-// SnapshotsStagingPath returns the path to the directory containing a temporary staging area for snapshots.
-// Use NewSnapshotStagingDir to generate a new staging area.
-func (dis *Distillery) SnapshotsStagingPath() string {
-	return filepath.Join(dis.SnapshotsDir(), "staging")
-}
-
-// SnapshotsArchivePath returns the path to the directory containing all exported archives.
-// Use NewSnapshotArchivePath to generate a path to a new archive in this directory.
-func (dis *Distillery) SnapshotsArchivePath() string {
-	return filepath.Join(dis.SnapshotsDir(), "archives")
-}
-
-// NewSnapshotArchivePath returns the path to a new archive with the provided prefix.
-// The path is guaranteed to not exist.
-func (dis *Distillery) NewSnapshotArchivePath(prefix string) (path string) {
-	// TODO: Consider moving these into a subdirectory with the provided prefix.
-	for path == "" || fsx.Exists(dis.Environment, path) {
-		name := dis.newSnapshotName(prefix) + ".tar.gz"
-		path = filepath.Join(dis.SnapshotsArchivePath(), name)
-	}
-	return
-}
-
-// newSnapshot name returns a new basename for a snapshot with the provided prefix.
-// The name is guaranteed to be unique within this process.
-func (*Distillery) newSnapshotName(prefix string) string {
-	suffix, _ := password.Password(64) // silently ignore any errors!
-	if prefix == "" {
-		prefix = "backup"
-	} else {
-		prefix = "snapshot-" + prefix
-	}
-	return fmt.Sprintf("%s-%d-%s", prefix, time.Now().Unix(), suffix)
-}
-
-// NewSnapshotStagingDir returns the path to a new snapshot directory.
-// The directory is guaranteed to have been freshly created.
-func (dis *Distillery) NewSnapshotStagingDir(prefix string) (path string, err error) {
-	for path == "" || environment.IsExist(err) {
-		path = filepath.Join(dis.SnapshotsStagingPath(), dis.newSnapshotName(prefix))
-		err = dis.Core.Environment.Mkdir(path, environment.DefaultFilePerm)
-	}
-	if err != nil {
-		path = ""
-	}
-	return
-}
-
 // SnapshotDescription is a description for a snapshot
 type SnapshotDescription struct {
 	Dest      string // destination path