feat: Implement filesystem to filesystem backup (#21)

cmd/backup.go

@@ -22,20 +22,20 @@ import (
 	"github.com/cluetec/lifeboat/internal/logging"
 	"github.com/cluetec/lifeboat/internal/source"
 	"github.com/spf13/cobra"
+	"io"
 	"log/slog"
-	"os"
 )
 
 // backupCmd represents the backup command
 var backupCmd = &cobra.Command{
 	Use:   "backup",
 	Short: "Execute the backup.",
 	Long:  "Execute the backup. Used config can be overridden by providing arguments.",
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		c, err := config.New()
 		if err != nil {
 			slog.Error("error while initializing config", "error", err)
-			os.Exit(1)
+			return err
 		}
 
 		logging.InitSlog(c.GetLogLevel())
@@ -45,11 +45,37 @@ var backupCmd = &cobra.Command{
 
 		slog.Debug("start of backup command")
 
-		source.Prepare(c.Source)
-		destination.Prepare(c.Destination)
+		s, err := source.New(c.Source)
+		if err != nil {
+			slog.Error("error while initializing source", "error", err)
+			return err
+		}
+		defer func() {
+			err := s.Reader.Close()
+			if err != nil {
+				slog.Error("error while closing source reader", "error", err)
+			}
+		}()
 
-		slog.Info("TODO: Do backup")
+		d, err := destination.New(c.Destination)
+		if err != nil {
+			slog.Error("error while initializing destination", "error", err)
+			return err
+		}
+		defer func() {
+			err := d.Writer.Close()
+			if err != nil {
+				slog.Error("error while closing destination writer", "error", err)
+			}
+		}()
+
+		n, err := io.Copy(d.Writer, s.Reader)
+		if err != nil {
+			slog.Error("error while doing the backup", "error", err)
+			return err
+		}
 
-		slog.Debug("end of backup command")
+		slog.Info("Backup successful", "writtenBytes", n)
+		return nil
 	},
 }

cmd/root.go

@@ -24,9 +24,11 @@ import (
 
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
-	Use:   "lb",
-	Short: "Perform backups from any source to any destination.",
-	Long:  "Lifeboat is a general purpose backup tool which supports backups for arbitrary sources and destinations.",
+	Use:           "lb",
+	Short:         "Perform backups from any source to any destination.",
+	Long:          "Lifeboat is a general purpose backup tool which supports backups for arbitrary sources and destinations.",
+	SilenceUsage:  true,
+	SilenceErrors: true,
 }
 
 // Execute adds all child commands to the root command and sets flags appropriately.

config.yaml

@@ -1,9 +1,9 @@
 source:
   type: filesystem
-  path: source
+  path: /tmp/source.txt
 
 destination:
   type: filesystem
-  path: destination
+  path: /tmp/destination.txt
 
 logLevel: debug

internal/destination/destination.go

@@ -19,18 +19,31 @@ package destination
 import (
 	"github.com/cluetec/lifeboat/internal/config"
 	"github.com/cluetec/lifeboat/internal/destination/filesystem"
+	"io"
 	"log/slog"
-	"os"
 )
 
-func Prepare(c config.DestinationConfig) {
+type Destination struct {
+	Writer io.WriteCloser
+}
+
+func New(c config.DestinationConfig) (*Destination, error) {
+	d := Destination{}
 	if c.Type == filesystem.Type {
-		filesystemConfig, err := filesystem.New(c.ResourceConfig)
+		filesystemConfig, err := filesystem.NewConfig(c.ResourceConfig)
 		if err != nil {
 			slog.Error("error while initializing filesystem destination config", "error", err)
-			os.Exit(1)
+			return nil, err
 		}
 
 		slog.Debug("filesystem destination config loaded", "config", filesystemConfig)
+
+		d.Writer, err = filesystem.NewWriter(filesystemConfig)
+		if err != nil {
+			slog.Error("error while initializing writer interface for filesystem destination", "error", err)
+			return nil, err
+		}
 	}
+
+	return &d, nil
 }

internal/destination/filesystem/config.go

@@ -27,7 +27,7 @@ type Config struct {
 	Path string
 }
 
-func New(c map[string]any) (*Config, error) {
+func NewConfig(c map[string]any) (*Config, error) {
 	var filesystemConfig Config
 
 	err := mapstructure.Decode(c, &filesystemConfig)

internal/destination/filesystem/writer.go

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2023 cluetec GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package filesystem
+
+import (
+	"errors"
+	"log/slog"
+	"os"
+)
+
+type Writer struct {
+	file *os.File
+}
+
+func NewWriter(c *Config) (*Writer, error) {
+	w := Writer{}
+
+	// Check if destination file already exists
+	_, err := os.Stat(c.Path)
+	if err == nil {
+		return nil, errors.New("destination file already exists")
+	} else if !errors.Is(err, os.ErrNotExist) {
+		slog.Error("error while checking if destination file already exists", "error", err)
+		return nil, err
+	}
+
+	// Create file
+	f, err := os.Create(c.Path)
+	if err != nil {
+		return nil, err
+	}
+
+	w.file = f
+	return &w, nil
+}
+
+func (w *Writer) Write(b []byte) (int, error) {
+	return w.file.Write(b)
+}
+
+func (w *Writer) Close() error {
+	slog.Debug("closing filesystem writer")
+
+	if w.file != nil {
+		if err := w.file.Close(); err != nil {
+			return err
+		}
+		w.file = nil
+	}
+	return nil
+}

internal/source/filesystem/config.go

@@ -27,7 +27,7 @@ type Config struct {
 	Path string
 }
 
-func New(c map[string]any) (*Config, error) {
+func NewConfig(c map[string]any) (*Config, error) {
 	var filesystemConfig Config
 
 	err := mapstructure.Decode(c, &filesystemConfig)

internal/source/filesystem/reader.go

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2023 cluetec GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package filesystem
+
+import (
+	"log/slog"
+	"os"
+)
+
+type Reader struct {
+	file *os.File
+}
+
+func NewReader(c *Config) (*Reader, error) {
+	r := Reader{}
+
+	f, err := os.Open(c.Path)
+	if err != nil {
+		return nil, err
+	}
+
+	r.file = f
+
+	return &r, nil
+}
+
+func (r *Reader) Read(b []byte) (int, error) {
+	return r.file.Read(b)
+}
+
+func (r *Reader) Close() error {
+	slog.Debug("closing filesystem reader")
+
+	if r.file != nil {
+		if err := r.file.Close(); err != nil {
+			return err
+		}
+		r.file = nil
+	}
+	return nil
+}

internal/source/source.go

@@ -19,18 +19,31 @@ package source
 import (
 	"github.com/cluetec/lifeboat/internal/config"
 	"github.com/cluetec/lifeboat/internal/source/filesystem"
+	"io"
 	"log/slog"
-	"os"
 )
 
-func Prepare(c config.SourceConfig) {
+type Source struct {
+	Reader io.ReadCloser
+}
+
+func New(c config.SourceConfig) (*Source, error) {
+	s := Source{}
 	if c.Type == filesystem.Type {
-		filesystemConfig, err := filesystem.New(c.ResourceConfig)
+		filesystemConfig, err := filesystem.NewConfig(c.ResourceConfig)
 		if err != nil {
 			slog.Error("error while initializing filesystem source config", "error", err)
-			os.Exit(1)
+			return nil, err
 		}
 
 		slog.Debug("filesystem source config loaded", "config", filesystemConfig)
+
+		s.Reader, err = filesystem.NewReader(filesystemConfig)
+		if err != nil {
+			slog.Error("error while initializing reader interface for filesystem source", "error", err)
+			return nil, err
+		}
 	}
+
+	return &s, nil
 }

internal_open_discussion.md

@@ -2,13 +2,13 @@
 
 ## Planned features
 
-- [ ] Step: 1
+- [x] Step: 1
   - [x] Init cobra & viper setup
-  - [ ] Dynamic config loading with viper (`type`)
-- [ ] Step: 2
-  - [ ] Init slog setup
-- [ ] Implement Filesystem to Filesystem backup
-  - [ ] Think about the interfaces
+  - [x] Dynamic config loading with viper (`type`)
+- [x] Step: 2
+  - [x] Init slog setup
+- [x] Implement Filesystem to Filesystem backup
+  - [x] Think about the interfaces
 - [ ] Implement Vault to Filesystem backup
 
 For later: