whoops

.gitignore

@@ -1,5 +1,4 @@
 **.sw*
-lastn
 **/testdata
 **/._*
 **/exec-*

lastn/lastn.go

@@ -0,0 +1,164 @@
+package lastn
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"local/storage"
+	"log"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"sort"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type Config struct {
+	N           int
+	RcloneConf  string
+	RcloneAlias string
+	Ns          string
+	Root        string
+	Store       string
+	StoreAddr   string
+	StoreUser   string
+	StorePass   string
+	Cmd         string
+}
+
+type LastN struct {
+	store storage.DB
+	conf  Config
+}
+
+func New(conf Config) (*LastN, error) {
+	var store storage.DB
+	var err error
+	switch conf.Store {
+	case "rclone":
+		store, err = storage.New(storage.TypeFromString(conf.Store), conf.RcloneConf, path.Join(conf.RcloneAlias+":"))
+	default:
+		store, err = storage.New(storage.TypeFromString(conf.Store), conf.StoreAddr, conf.StoreUser, conf.StorePass)
+	}
+	if err != nil {
+		return nil, err
+	}
+	root, err := filepath.Abs(conf.Root)
+	conf.Root = root
+	return &LastN{
+		store: store,
+		conf:  conf,
+	}, err
+}
+
+func (lastN *LastN) Push() error {
+	root := lastN.conf.Root
+	store := lastN.store
+	root, err := filepath.Abs(root)
+	if err != nil {
+		return err
+	}
+	archive := path.Join(
+		os.TempDir(),
+		fmt.Sprintf(
+			"%s.%s.tar",
+			time.Now().Format("2006.01.02.15.04.05"),
+			uuid.New().String(),
+		),
+	)
+	cmd := exec.Command(
+		"tar",
+		"-czf",
+		archive,
+		"-C",
+		path.Dir(root),
+		path.Base(root),
+	)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("%v: %s", err, out)
+	}
+	b, err := ioutil.ReadFile(archive)
+	if err != nil {
+		return err
+	}
+	log.Println("Created backup", path.Base(archive))
+	return store.Set(path.Base(archive), b, lastN.conf.Ns)
+}
+
+func (lastN *LastN) Clean() error {
+	n := lastN.conf.N
+	store := lastN.store
+	backups, err := store.List([]string{lastN.conf.Ns})
+	if err != nil {
+		return err
+	}
+	sort.Strings(backups)
+	for i := 0; i < len(backups)-n; i++ {
+		log.Println("Pruning old backup", backups[i])
+		err := store.Set(backups[i], nil, lastN.conf.Ns)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (lastN *LastN) List() error {
+	store := lastN.store
+	backups, err := store.List([]string{lastN.conf.Ns})
+	if err != nil {
+		return err
+	}
+	sort.Strings(backups)
+	for _, backup := range backups {
+		log.Println(backup)
+	}
+	return nil
+}
+
+func (lastN *LastN) Restore() error {
+	root := lastN.conf.Root + "-restore"
+	os.RemoveAll(root)
+	if _, err := os.Stat(root); os.IsNotExist(err) {
+		if err := os.MkdirAll(root, os.ModePerm); err != nil {
+			return err
+		}
+	}
+	store := lastN.store
+	backups, err := store.List([]string{lastN.conf.Ns})
+	if err != nil {
+		return fmt.Errorf("cannot list: %v", err)
+	}
+	sort.Strings(backups)
+	backup := backups[len(backups)-1]
+	b, err := store.Get(backup, lastN.conf.Ns)
+	if err != nil {
+		return fmt.Errorf("cannot get %s: %v", backup, err)
+	}
+	log.Printf("restoring %s (%v) in %s", backup, len(b), root)
+	cmd := exec.Command(
+		"tar",
+		"-C",
+		root,
+		"-xzf",
+		"-",
+	)
+	stdin, err := cmd.StdinPipe()
+	if err != nil {
+		return fmt.Errorf("cannot get stdin: %v", err)
+	}
+	go func() {
+		defer stdin.Close()
+		io.Copy(stdin, bytes.NewReader(b))
+	}()
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("failed tar -xf: %v: %s", err, out)
+	}
+	return nil
+}

lastn/lastn_test.go

@@ -0,0 +1,92 @@
+package lastn
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+	"testing"
+	"time"
+)
+
+func TestLastN(t *testing.T) {
+	d, clean := makeJunk(t)
+	defer clean()
+
+	conf := Config{
+		N:     3,
+		Ns:    "b",
+		Root:  d,
+		Store: "map",
+	}
+	lastn, err := New(conf)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := lastn.Push(); err != nil {
+		t.Fatal(err)
+	}
+
+	was := log.Writer()
+	buff := bytes.NewBuffer(nil)
+	log.SetOutput(buff)
+	defer log.SetOutput(was)
+	if err := lastn.List(); err != nil {
+		t.Fatal(err)
+	} else if !bytes.Contains(buff.Bytes(), []byte(time.Now().Format("2006.01.02"))) {
+		t.Fatal(string(buff.Bytes()))
+	}
+	log.SetOutput(was)
+
+	restored := path.Join(d+"-restore", path.Base(d))
+
+	if err := lastn.Restore(); err != nil {
+		t.Fatal(err)
+	} else if _, err := os.Stat(restored); os.IsNotExist(err) {
+		t.Fatal(err)
+	} else if err != nil {
+		t.Fatal(err)
+	} else if files, err := ioutil.ReadDir(restored); err != nil {
+		t.Fatal(err)
+	} else if len(files) != 3 {
+		t.Fatal(len(files))
+	} else {
+		for _, file := range files {
+			if b, err := ioutil.ReadFile(path.Join(restored, file.Name())); err != nil {
+				t.Fatal(err)
+			} else if v := string(b); v != "hi" {
+				t.Fatal(v)
+			}
+		}
+	}
+
+	for i := 0; i < 10; i++ {
+		if err := lastn.Push(); err != nil {
+			t.Fatal(err)
+		}
+	}
+	if saved, err := lastn.store.List([]string{lastn.conf.Ns}); err != nil {
+		t.Fatal(err)
+	} else if len(saved) != 11 {
+		t.Fatal(len(saved))
+	}
+}
+
+func makeJunk(t *testing.T) (string, func()) {
+	d, err := ioutil.TempDir(os.TempDir(), "lastNtest*")
+	if err != nil {
+		t.Fatal(err)
+	}
+	for i := 0; i < 3; i++ {
+		if err := ioutil.WriteFile(path.Join(d, fmt.Sprint(i)), []byte("hi"), os.ModePerm); err != nil {
+			os.RemoveAll(d)
+			t.Fatal(err)
+		}
+	}
+	return d, func() {
+		os.RemoveAll(d)
+	}
+}