From fd84b2fdfd88435e133e4aba59a3facded3cc01d Mon Sep 17 00:00:00 2001 From: Vincent Batts Date: Mon, 20 Jul 2015 15:51:20 -0400 Subject: [PATCH] cmd/tar-split: adding a cli tool for asm/disasm --- cmd/tar-split/README.md | 25 ++++++ cmd/tar-split/main.go | 175 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 200 insertions(+) create mode 100644 cmd/tar-split/README.md create mode 100644 cmd/tar-split/main.go diff --git a/cmd/tar-split/README.md b/cmd/tar-split/README.md new file mode 100644 index 0000000..5451be0 --- /dev/null +++ b/cmd/tar-split/README.md @@ -0,0 +1,25 @@ +## tar-split utility + + +## Usage + +### Disassembly + +```bash +$ sha256sum archive.tar +d734a748db93ec873392470510b8a1c88929abd8fae2540dc43d5b26f7537868 archive.tar +$ mkdir ./x +$ tar-split d --output tar-data.json.gz ./archive.tar | tar -C ./x -x +time="2015-07-20T15:45:04-04:00" level=info msg="created tar-data.json.gz from ./archive.tar (read 204800 bytes)" +``` + +### Assembly + +```bash +$ tar-split a --output new.tar --input ./tar-data.json.gz --path ./x/ +INFO[0000] created new.tar from ./x/ and ./tar-data.json.gz (wrote 204800 bytes) +$ sha256sum new.tar +d734a748db93ec873392470510b8a1c88929abd8fae2540dc43d5b26f7537868 new.tar +``` + + diff --git a/cmd/tar-split/main.go b/cmd/tar-split/main.go new file mode 100644 index 0000000..8c631b0 --- /dev/null +++ b/cmd/tar-split/main.go @@ -0,0 +1,175 @@ +// go:generate git tag | tail -1 +package main + +import ( + "compress/gzip" + "io" + "os" + + "github.com/Sirupsen/logrus" + "github.com/codegangsta/cli" + "github.com/vbatts/tar-split/tar/asm" + "github.com/vbatts/tar-split/tar/storage" +) + +func main() { + app := cli.NewApp() + app.Name = "tar-split" + app.Usage = "tar assembly and disassembly utility" + app.Version = "0.9.2" + app.Author = "Vincent Batts" + app.Email = "vbatts@hashbangbash.com" + app.Action = cli.ShowAppHelp + app.Before = func(c *cli.Context) error { + logrus.SetOutput(os.Stderr) + if c.Bool("debug") { + logrus.SetLevel(logrus.DebugLevel) + } + return nil + } + app.Flags = []cli.Flag{ + cli.BoolFlag{ + Name: "debug, D", + Usage: "debug output", + // defaults to false + }, + } + app.Commands = []cli.Command{ + { + Name: "disasm", + Aliases: []string{"d"}, + Usage: "disassemble the input tar stream", + Action: CommandDisasm, + Flags: []cli.Flag{ + cli.StringFlag{ + Name: "output", + Value: "tar-data.json.gz", + Usage: "output of disassembled tar stream", + }, + }, + }, + { + Name: "asm", + Aliases: []string{"a"}, + Usage: "assemble tar stream", + Action: CommandAsm, + Flags: []cli.Flag{ + cli.StringFlag{ + Name: "input", + Value: "tar-data.json.gz", + Usage: "input of disassembled tar stream", + }, + cli.StringFlag{ + Name: "output", + Value: "-", + Usage: "reassembled tar archive", + }, + cli.StringFlag{ + Name: "path", + Value: "", + Usage: "relative path of extracted tar", + }, + }, + }, + } + + if err := app.Run(os.Args); err != nil { + logrus.Fatal(err) + } +} + +func CommandDisasm(c *cli.Context) { + if len(c.Args()) != 1 { + logrus.Fatalf("please specify tar to be disabled ") + } + if len(c.String("output")) == 0 { + logrus.Fatalf("--output filename must be set") + } + + // Set up the tar input stream + var inputStream io.Reader + if c.Args()[0] == "-" { + inputStream = os.Stdin + } else { + fh, err := os.Open(c.Args()[0]) + if err != nil { + logrus.Fatal(err) + } + defer fh.Close() + inputStream = fh + } + + // Set up the metadata storage + mf, err := os.OpenFile(c.String("output"), os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(0600)) + if err != nil { + logrus.Fatal(err) + } + defer mf.Close() + mfz := gzip.NewWriter(mf) + defer mfz.Close() + metaPacker := storage.NewJSONPacker(mfz) + + // we're passing nil here for the file putter, because the ApplyDiff will + // handle the extraction of the archive + its, err := asm.NewInputTarStream(inputStream, metaPacker, nil) + if err != nil { + logrus.Fatal(err) + } + i, err := io.Copy(os.Stdout, its) + if err != nil { + logrus.Fatal(err) + } + logrus.Infof("created %s from %s (read %d bytes)", c.String("output"), c.Args()[0], i) +} + +func CommandAsm(c *cli.Context) { + if len(c.Args()) > 0 { + logrus.Warnf("%d additional arguments passed are ignored", len(c.Args())) + } + if len(c.String("input")) == 0 { + logrus.Fatalf("--input filename must be set") + } + if len(c.String("output")) == 0 { + logrus.Fatalf("--output filename must be set ([FILENAME|-])") + } + if len(c.String("path")) == 0 { + logrus.Fatalf("--path must be set") + } + + var outputStream io.Writer + if c.String("output") == "-" { + outputStream = os.Stdout + } else { + fh, err := os.Create(c.String("output")) + if err != nil { + logrus.Fatal(err) + } + defer fh.Close() + outputStream = fh + } + + // Get the tar metadata reader + mf, err := os.Open(c.String("input")) + if err != nil { + logrus.Fatal(err) + } + defer mf.Close() + mfz, err := gzip.NewReader(mf) + if err != nil { + logrus.Fatal(err) + } + defer mfz.Close() + + metaUnpacker := storage.NewJSONUnpacker(mfz) + // XXX maybe get the absolute path here + fileGetter := storage.NewPathFileGetter(c.String("path")) + + ots := asm.NewOutputTarStream(fileGetter, metaUnpacker) + defer ots.Close() + i, err := io.Copy(outputStream, ots) + if err != nil { + logrus.Fatal(err) + } + + logrus.Infof("created %s from %s and %s (wrote %d bytes)", c.String("output"), c.String("path"), c.String("input"), i) +}