'wdcli backup': Move to separate package

internal/component/backup.go

@@ -0,0 +1,43 @@
+package component
+
+import (
+	"io"
+
+	"github.com/tkw1536/goprogram/stream"
+)
+
+// Backupable represents a component with a Backup method
+type Backupable interface {
+	Component
+
+	// BackupName returns a new name to be used as an argument for path.
+	BackupName() string
+
+	// Backup backs up this component into the destination path path
+	Backup(context BackupContext) error
+}
+
+// BackupContext is the context for backups
+type BackupContext interface {
+	// IO returns the input output stream belonging to this backup file
+	IO() stream.IOStream
+
+	// Name creates a new directory inside the destination.
+	// Passing the empty path creates the destination as a directory.
+	//
+	// It then allows op to fill the file.
+	AddDirectory(path string, op func() error) error
+
+	// CopyFile copies a file from source to dst.
+	CopyFile(dest, src string) error
+
+	// AddFile creates a new file at the provided path inside the destination.
+	// Passing the empty path creates the destination as a file.
+	//
+	// It then allows op to write to the file.
+	//
+	// The op function must not retain file.
+	// The underlying file does not need to be closed.
+	// AddFile will not return before op has returned.
+	AddFile(path string, op func(file io.Writer) error) error
+}

internal/component/component.go

@@ -3,7 +3,6 @@ package component
 
 import (
 	"github.com/FAU-CDI/wisski-distillery/internal/config"
-	"github.com/tkw1536/goprogram/stream"
 )
 
 // Component represents a logical subsystem of the distillery.
@@ -46,20 +45,6 @@ type Installable interface {
 	Context(parent InstallationContext) InstallationContext
 }
 
-// Backupable represents a component with a Backup method
-type Backupable interface {
-	Component
-
-	// BackupName returns a new name to be used as an argument for path.
-	BackupName() string
-
-	// Backup backs up this component into the destination path path.
-	//
-	// The destination path may be a folder or directory, depending on the component.
-	// The destination path does not need to exist.
-	Backup(io stream.IOStream, path string) error
-}
-
 // ComponentBase implements base functionality for a component
 type ComponentBase struct {
 	Dir    string         // Dir is the directory this component lives in

internal/component/control/backup.go

@@ -1,12 +1,9 @@
 package control
 
 import (
-	"io/fs"
-	"os"
 	"path/filepath"
 
-	"github.com/FAU-CDI/wisski-distillery/pkg/fsx"
-	"github.com/tkw1536/goprogram/stream"
+	"github.com/FAU-CDI/wisski-distillery/internal/component"
 )
 
 func (*Control) BackupName() string {
@@ -14,27 +11,18 @@ func (*Control) BackupName() string {
 }
 
 // Backup backups all control plane configuration files into dest
-func (control *Control) Backup(io stream.IOStream, dest string) error {
-	// create the destination directory, TODO: outsource this
-	if err := os.Mkdir(dest, fs.ModeDir); err != nil {
-		return err
-	}
-
+func (control *Control) Backup(context component.BackupContext) error {
 	files := control.backupFiles()
-	for _, src := range files {
-		dst := filepath.Join(dest, filepath.Base(src)) // destination path
 
-		// if the src file does not exist, don't copy it!
-		if !fsx.IsFile(src) { // TODO: log this somewhere
-			continue
+	return context.AddDirectory("", func() error {
+		for _, src := range files {
+			name := filepath.Base(src)
+			if err := context.CopyFile(name, src); err != nil {
+				return err
+			}
 		}
-
-		if err := fsx.CopyFile(dst, src); err != nil {
-			return err
-		}
-	}
-
-	return nil
+		return nil
+	})
 }
 
 // backupfiles lists the files to be backed up.

internal/component/sql/backup.go

@@ -2,9 +2,9 @@ package sql
 
 import (
 	"errors"
-	"os"
+	"io"
 
-	"github.com/tkw1536/goprogram/stream"
+	"github.com/FAU-CDI/wisski-distillery/internal/component"
 )
 
 var errSQLBackup = errors.New("SQLBackup: Mysqldump returned non-zero exit code")
@@ -14,22 +14,17 @@ func (*SQL) BackupName() string {
 }
 
 // Backup makes a backup of all SQL databases into the path dest.
-func (sql *SQL) Backup(io stream.IOStream, dest string) error {
-	// open the file, TODO: Outsource this to context
-	writer, err := os.Create(dest)
-	if err != nil {
-		return err
-	}
-	defer writer.Close()
+func (sql *SQL) Backup(context component.BackupContext) error {
+	return context.AddFile("", func(file io.Writer) error {
+		io := context.IO().Streams(file, nil, nil, 0).NonInteractive()
+		code, err := sql.Stack().Exec(io, "sql", "mysqldump", "--all-databases")
+		if err != nil {
+			return err
+		}
+		if code != 0 {
+			return errSQLBackup
+		}
+		return nil
+	})
 
-	// run sqldump
-	io = io.Streams(writer, nil, nil, 0).NonInteractive()
-	code, err := sql.Stack().Exec(io, "sql", "mysqldump", "--all-databases")
-	if err != nil {
-		return err
-	}
-	if code != 0 {
-		return errSQLBackup
-	}
-	return nil
 }

internal/component/triplestore/backup.go

@@ -2,48 +2,34 @@ package triplestore
 
 import (
 	"encoding/json"
-	"io/fs"
-	"os"
-	"path/filepath"
+	"io"
 
-	"github.com/tkw1536/goprogram/stream"
+	"github.com/FAU-CDI/wisski-distillery/internal/component"
 )
 
 func (ts *Triplestore) BackupName() string { return "triplestore" }
 
 // Backup makes a backup of all Triplestore repositories databases into the path dest.
-func (ts *Triplestore) Backup(io stream.IOStream, dest string) error {
+func (ts *Triplestore) Backup(context component.BackupContext) error {
 
-	// list all the repositories
+	// list all the directories
 	repos, err := ts.listRepositories()
 	if err != nil {
 		return err
 	}
 
-	// create the base directory, todo: outsource this
-	if err := os.Mkdir(dest, fs.ModeDir); err != nil {
-		return err
-	}
-
-	// iterate over all the repositories
-	for _, repo := range repos {
-		if rErr := (func(repo Repository) error {
-			name := filepath.Join(dest, repo.ID+".nq")
-
-			// todo: outsource this
-			dest, err := os.Create(name)
-			if err != nil {
+	// then backup each file separatly
+	return context.AddDirectory("", func() error {
+		for _, repo := range repos {
+			if err := context.AddFile(repo.ID+".nq", func(file io.Writer) error {
+				_, err := ts.Snapshot(file, repo.ID)
+				return err
+			}); err != nil {
 				return err
 			}
-			defer dest.Close()
-
-			_, err = ts.Snapshot(dest, repo.ID)
-			return err
-		}(repo)); err == nil && rErr != nil {
-			err = rErr
 		}
-	}
-	return err
+		return nil
+	})
 }
 
 func (ts Triplestore) listRepositories() (repos []Repository, err error) {