snapshots: Unify 'snapshot' and 'backup' code

cmd/backup.go

@@ -1,6 +1,9 @@
 package cmd
 
 import (
+	"io"
+	"path/filepath"
+
 	wisski_distillery "github.com/FAU-CDI/wisski-distillery"
 	"github.com/FAU-CDI/wisski-distillery/internal/component/snapshots"
 	"github.com/FAU-CDI/wisski-distillery/internal/core"
@@ -41,102 +44,155 @@ var errBackupFailed = exit.Error{
 
 func (bk backupC) Run(context wisski_distillery.Context) error {
 	dis := context.Environment
-	var err error
 
+	// prune old backups
 	if !bk.NoPrune {
 		defer logging.LogOperation(func() error {
 			return dis.SnapshotManager().PruneBackups(context.IOStream)
 		}, context.IOStream, "Pruning old backups")
 	}
 
-	// determine the target path for the archive
+	// do the handling
-	var sPath string
+	err := handleSnapshotLike(context, SnapshotFlags{
-	if !bk.StagingOnly {
+		Dest:        bk.Positionals.Dest,
-		// regular mode: create a temporary staging directory
+		Slug:        "",
-		logging.LogMessage(context.IOStream, "Creating new backup staging directory")
+		Title:       "Backup",
-		sPath, err = dis.SnapshotManager().NewStagingDir("")
+		StagingOnly: bk.StagingOnly,
-		if err != nil {
+
-			return errSnapshotFailed.Wrap(err)
+		Do: func(dest string) SnapshotLike {
-		}
+			backup := dis.SnapshotManager().NewBackup(context.IOStream, snapshots.BackupDescription{
-		defer func() {
+				Dest:                dest,
-			logging.LogMessage(context.IOStream, "Removing snapshot staging directory")
+				ConcurrentSnapshots: bk.ConcurrentSnapshots,
-			dis.Environment.RemoveAll(sPath)
+			})
-		}()
+			return &backup
+		},
+	})
+
+	if err != nil {
+		return errBackupFailed.Wrap(err)
+	}
+	return nil
+}
+
+type SnapshotFlags struct {
+	Dest        string
+	Slug        string
+	Title       string // "Backup" or "Snapshot"
+	StagingOnly bool
+
+	Do func(dest string) SnapshotLike
+}
+
+type SnapshotLike interface {
+	LogEntry() models.Snapshot
+	Report(w io.Writer) (int, error)
+}
+
+func handleSnapshotLike(context wisski_distillery.Context, flags SnapshotFlags) (err error) {
+	dis := context.Environment
+
+	// determine target paths
+	logging.LogMessage(context.IOStream, "Determining target paths")
+	var stagingDir, archivePath string
+	if flags.StagingOnly {
+		stagingDir = flags.Dest
 	} else {
-		// staging mode: use dest as a destination
+		archivePath = flags.Dest
-		sPath = bk.Positionals.Dest
-		if sPath == "" {
-			sPath, err = dis.SnapshotManager().NewStagingDir("")
-			if err != nil {
-				return errSnapshotFailed.Wrap(err)
-			}
-		}
-
-		// create the directory (if it doesn't already exist)
-		logging.LogMessage(context.IOStream, "Creating staging directory")
-		err = dis.Core.Environment.Mkdir(sPath, environment.DefaultDirPerm)
-		if !environment.IsExist(err) && err != nil {
-			return errSnapshotFailed.WithMessageF(err)
-		}
-		err = nil
 	}
-	context.Println(sPath)
+	if stagingDir == "" {
+		stagingDir, err = dis.SnapshotManager().NewStagingDir(flags.Slug)
+		if err != nil {
+			return err
+		}
+	}
+	if !flags.StagingOnly && archivePath == "" {
+		archivePath = dis.SnapshotManager().NewArchivePath(flags.Slug)
+	}
+	context.Printf("Staging Directory: %s\n", stagingDir)
+	context.Printf("Archive Path:      %s\n", archivePath)
 
-	var logEntry models.Snapshot
+	// create the staging directory
+	logging.LogMessage(context.IOStream, "Creating staging directory")
+	err = dis.Core.Environment.Mkdir(stagingDir, environment.DefaultDirPerm)
+	if !environment.IsExist(err) && err != nil {
+		return err
+	}
+
+	// if it was requested to not do staging only
+	// we need the staging directory to be deleted at the end
+	if !flags.StagingOnly {
+		defer func() {
+			logging.LogMessage(context.IOStream, "Removing staging directory")
+			dis.Environment.RemoveAll(stagingDir)
+		}()
+	}
+
+	// create the actual snapshot or backup
+	// write out the report
+	// and retain a log entry
+	var entry models.Snapshot
 	logging.LogOperation(func() error {
-		backup := dis.SnapshotManager().NewBackup(context.IOStream, snapshots.BackupDescription{
+		// do the snapshot!
-			Dest:                sPath,
+		sl := flags.Do(stagingDir)
-			ConcurrentSnapshots: bk.ConcurrentSnapshots,
-		})
-		backup.WriteReport(dis.Core.Environment, context.IOStream)
-		logEntry = backup.LogEntry()
-		return nil
-	}, context.IOStream, "Generating Backup")
 
-	// create the archive path
+		// create a log entry
-	archivePath := bk.Positionals.Dest
+		entry = sl.LogEntry()
-	if archivePath == "" {
-		archivePath = dis.SnapshotManager().NewArchivePath("")
-	}
 
-	// do the logging
+		// find the report path
-	if bk.Positionals.Dest == "" {
+		reportPath := filepath.Join(stagingDir, "report.txt")
-		defer logging.LogOperation(func() error {
+		context.Println(reportPath)
-			if bk.StagingOnly {
-				logEntry.Path = sPath
-				logEntry.Packed = false
-			} else {
-				logEntry.Path = archivePath
-				logEntry.Packed = true
-			}
 
-			return dis.Instances().AddSnapshotLog(logEntry)
+		// create the path
-		}, context.IOStream, "Writing Log Entry")
+		report, err := dis.Environment.Create(reportPath, environment.DefaultFilePerm)
-	}
+		if err != nil {
+			return err
+		}
 
-	// if we requested to only have a staging area, then we are done
+		// and write out the report
-	if bk.StagingOnly {
+		{
-		context.Printf("Wrote %s\n", sPath)
+			_, err := sl.Report(report)
+			return err
+		}
+	}, context.IOStream, "Generating %s", flags.Title)
+
+	// if we only requested staging
+	// all that is left is to write the log entry
+	if flags.StagingOnly {
+		logging.LogMessage(context.IOStream, "Writing Log Entry")
+
+		// write out the log entry
+		entry.Path = stagingDir
+		entry.Packed = false
+		dis.Instances().AddSnapshotLog(entry)
+
+		context.Printf("Wrote %s\n", stagingDir)
 		return nil
 	}
 
-	// and write everything into it!
+	// package everything up as an archive!
-	var count int64
 	if err := logging.LogOperation(func() error {
-		context.IOStream.Println(archivePath)
+		var count int64
+		defer func() { context.Printf("Wrote %d byte(s) to %s\n", count, archivePath) }()
 
 		st := status.NewWithCompat(context.Stdout, 1)
 		st.Start()
 		defer st.Stop()
 
-		count, err = targz.Package(dis.Core.Environment, archivePath, sPath, func(dst, src string) {
+		count, err = targz.Package(dis.Core.Environment, archivePath, stagingDir, func(dst, src string) {
 			st.Set(0, dst)
 		})
-		return err
-	}, context.IOStream, "Writing backup archive"); err != nil {
-		return errSnapshotFailed.Wrap(err)
-	}
-	context.Printf("Wrote %d byte(s) to %s\n", count, archivePath)
 
+		return err
+	}, context.IOStream, "Writing archive"); err != nil {
+		return err
+	}
+
+	// write out the log entry
+	logging.LogMessage(context.IOStream, "Writing Log Entry")
+	entry.Path = archivePath
+	entry.Packed = true
+	dis.Instances().AddSnapshotLog(entry)
+
+	// and we're done!
 	return nil
 }

cmd/snapshot.go

@@ -1,17 +1,10 @@
 package cmd
 
 import (
-	"io/fs"
-
 	wisski_distillery "github.com/FAU-CDI/wisski-distillery"
 	"github.com/FAU-CDI/wisski-distillery/internal/component/snapshots"
 	"github.com/FAU-CDI/wisski-distillery/internal/core"
-	"github.com/FAU-CDI/wisski-distillery/internal/models"
-	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
-	"github.com/FAU-CDI/wisski-distillery/pkg/logging"
-	"github.com/FAU-CDI/wisski-distillery/pkg/targz"
 	"github.com/tkw1536/goprogram/exit"
-	"github.com/tkw1536/goprogram/status"
 )
 
 // Snapshot creates a snapshot of an instance
@@ -43,111 +36,31 @@ var errSnapshotFailed = exit.Error{
 }
 
 func (bi snapshot) Run(context wisski_distillery.Context) error {
-	// TODO: Cleanup this code!
-
 	dis := context.Environment
+
+	// find the instance!
 	instance, err := dis.Instances().WissKI(bi.Positionals.Slug)
 	if err != nil {
 		return err
 	}
 
-	logging.LogMessage(context.IOStream, "Creating snapshot of instance %s", bi.Positionals.Slug)
+	// do a snapshot of it!
+	err = handleSnapshotLike(context, SnapshotFlags{
+		Dest:        bi.Positionals.Dest,
+		Slug:        bi.Positionals.Slug,
+		Title:       "Snapshot",
+		StagingOnly: bi.StagingOnly,
 
-	// determine the target path for the archive
+		Do: func(dest string) SnapshotLike {
-	var sPath string
+			snapshot := dis.SnapshotManager().NewSnapshot(instance, context.IOStream, snapshots.SnapshotDescription{
+				Dest: dest,
+			})
+			return &snapshot
+		},
+	})
 
-	if !bi.StagingOnly {
+	if err != nil {
-		// regular mode: create a temporary staging directory
-		logging.LogMessage(context.IOStream, "Creating new snapshot staging directory")
-		sPath, err = dis.SnapshotManager().NewStagingDir(instance.Slug)
-		if err != nil {
-			return errSnapshotFailed.Wrap(err)
-		}
-		defer func() {
-			logging.LogMessage(context.IOStream, "Removing snapshot staging directory")
-			dis.Core.Environment.RemoveAll(sPath)
-		}()
-	} else {
-		// staging mode: use dest as a destination
-		sPath = bi.Positionals.Dest
-		if sPath == "" {
-			sPath, err = dis.SnapshotManager().NewStagingDir(instance.Slug)
-			if err != nil {
-				return errSnapshotFailed.Wrap(err)
-			}
-		}
-
-		// create the directory (if it doesn't already exist)
-		logging.LogMessage(context.IOStream, "Creating staging directory")
-		err = dis.Core.Environment.Mkdir(sPath, fs.ModePerm)
-		if !environment.IsExist(err) && err != nil {
-			return errSnapshotFailed.WithMessageF(err)
-		}
-		err = nil
-	}
-	context.Println(sPath)
-
-	// TODO: Allow skipping backups of individual parts and make them concurrent!
-
-	// take a snapshot into the staging area!
-	var logEntry models.Snapshot
-	logging.LogOperation(func() error {
-		sreport := dis.SnapshotManager().NewSnapshot(instance, context.IOStream, snapshots.SnapshotDescription{
-			Dest:      sPath,
-			Keepalive: bi.Keepalive,
-		})
-
-		// write out the report, ignoring any errors!
-		sreport.WriteReport(dis.Core.Environment, context.IOStream)
-
-		logEntry = sreport.LogEntry()
-
-		return nil
-	}, context.IOStream, "Generating Snapshot")
-
-	// create the archive path
-	archivePath := bi.Positionals.Dest
-	if archivePath == "" {
-		archivePath = dis.SnapshotManager().NewArchivePath("")
-	}
-
-	// do the logging
-	if bi.Positionals.Dest == "" {
-		defer logging.LogOperation(func() error {
-			if bi.StagingOnly {
-				logEntry.Path = sPath
-				logEntry.Packed = false
-			} else {
-				logEntry.Path = archivePath
-				logEntry.Packed = true
-			}
-
-			return dis.Instances().AddSnapshotLog(logEntry)
-		}, context.IOStream, "Writing Log Entry")
-	}
-	// if we requested to only have a staging area, then we are done
-	if bi.StagingOnly {
-		context.Printf("Wrote %s\n", sPath)
-		return nil
-	}
-
-	// and write everything into it!
-	// TODO: Should we move the open call to here?
-	var count int64
-	if err := logging.LogOperation(func() error {
-		context.IOStream.Println(archivePath)
-
-		st := status.NewWithCompat(context.Stdout, 1)
-		st.Start()
-		defer st.Stop()
-
-		count, err = targz.Package(dis.Core.Environment, archivePath, sPath, func(dst, src string) {
-			st.Set(0, dst)
-		})
-		return err
-	}, context.IOStream, "Writing snapshot archive"); err != nil {
 		return errSnapshotFailed.Wrap(err)
 	}
-	context.Printf("Wrote %d byte(s) to %s\n", count, archivePath)
 	return nil
 }

internal/component/snapshots/report.go

@@ -4,13 +4,9 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"path/filepath"
 	"strings"
 
 	"github.com/FAU-CDI/wisski-distillery/pkg/countwriter"
-	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
-	"github.com/FAU-CDI/wisski-distillery/pkg/logging"
-	"github.com/tkw1536/goprogram/stream"
 )
 
 func (snapshot Snapshot) String() string {
@@ -65,26 +61,6 @@ func (snapshot Snapshot) Report(w io.Writer) (int, error) {
 	return ww.Sum()
 }
 
-// WriteReport writes out the report belonging to this snapshot.
-// It is a separate function, to allow writing it indepenently of the rest.
-func (snapshot *Snapshot) WriteReport(env environment.Environment, stream stream.IOStream) error {
-	return logging.LogOperation(func() error {
-		reportPath := filepath.Join(snapshot.Description.Dest, "report.txt")
-		stream.Println(reportPath)
-
-		// create the report file!
-		report, err := env.Create(reportPath, environment.DefaultFilePerm)
-		if err != nil {
-			return err
-		}
-		defer report.Close()
-
-		// print the report into it!
-		_, err = io.WriteString(report, snapshot.String())
-		return err
-	}, stream, "Writing snapshot report")
-}
-
 // Strings turns this backup into a string for the BackupReport.
 func (backup Backup) String() string {
 	var builder strings.Builder
@@ -132,23 +108,3 @@ func (backup Backup) Report(w io.Writer) (int, error) {
 
 	return cw.Sum()
 }
-
-// WriteReport writes out the report belonging to this backup.
-// It is a separate function, to allow writing it indepenently of the rest.
-func (backup Backup) WriteReport(env environment.Environment, stream stream.IOStream) error {
-	return logging.LogOperation(func() error {
-		reportPath := filepath.Join(backup.Description.Dest, "report.txt")
-		stream.Println(reportPath)
-
-		// create the report file!
-		report, err := env.Create(reportPath, environment.DefaultFilePerm)
-		if err != nil {
-			return err
-		}
-		defer report.Close()
-
-		// print the report into it!
-		_, err = io.WriteString(report, backup.String())
-		return err
-	}, stream, "Writing backup report")
-}