cmd/swarm: allow uploading from stdin (#3744)

- intended to be a swarm alternative to termbin.com
- added --stdin flag to swarm executable. if set, swarm will
  read data from stdin and postRaw it.

cmd/swarm/main.go

@@ -112,6 +112,14 @@ var (
 		Name:  "defaultpath",
 		Usage: "path to file served for empty url path (none)",
 	}
+	SwarmUpFromStdinFlag = cli.BoolFlag{
+		Name:  "stdin",
+		Usage: "reads data to be uploaded from stdin",
+	}
+	SwarmUploadMimeType = cli.StringFlag{
+		Name:  "mime",
+		Usage: "force mime type",
+	}
 	CorsStringFlag = cli.StringFlag{
 		Name:  "corsdomain",
 		Usage: "Domain on which to send Access-Control-Allow-Origin header (multiple domains can be supplied separated by a ',')",
@@ -244,6 +252,8 @@ Cleans database of corrupted entries.
 		SwarmRecursiveUploadFlag,
 		SwarmWantManifestFlag,
 		SwarmUploadDefaultPath,
+		SwarmUpFromStdinFlag,
+		SwarmUploadMimeType,
 	}
 	app.Flags = append(app.Flags, debug.Flags...)
 	app.Before = func(ctx *cli.Context) error {

cmd/swarm/upload.go

@@ -20,6 +20,8 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"io"
+	"io/ioutil"
 	"os"
 	"os/user"
 	"path"
@@ -31,21 +33,42 @@ import (
 )
 
 func upload(ctx *cli.Context) {
+
 	args := ctx.Args()
 	var (
 		bzzapi       = strings.TrimRight(ctx.GlobalString(SwarmApiFlag.Name), "/")
 		recursive    = ctx.GlobalBool(SwarmRecursiveUploadFlag.Name)
 		wantManifest = ctx.GlobalBoolT(SwarmWantManifestFlag.Name)
 		defaultPath  = ctx.GlobalString(SwarmUploadDefaultPath.Name)
+		fromStdin    = ctx.GlobalBool(SwarmUpFromStdinFlag.Name)
+		mimeType     = ctx.GlobalString(SwarmUploadMimeType.Name)
 	)
+
+	var client = swarm.NewClient(bzzapi)
+	var entry swarm.ManifestEntry
+	var file string
+
 	if len(args) != 1 {
-		utils.Fatalf("Need filename as the first and only argument")
+		if fromStdin {
+			tmp, err := ioutil.TempFile("", "swarm-stdin")
+			if err != nil {
+				utils.Fatalf("error create tempfile: %s", err)
+			}
+			defer os.Remove(tmp.Name())
+			n, err := io.Copy(tmp, os.Stdin)
+			if err != nil {
+				utils.Fatalf("error copying stdin to tempfile: %s", err)
+			} else if n == 0 {
+				utils.Fatalf("error reading from stdin: zero length")
+			}
+			file = tmp.Name()
+		} else {
+			utils.Fatalf("Need filename as the first and only argument")
+		}
+	} else {
+		file = args[0]
 	}
 
-	var (
-		file   = args[0]
-		client = swarm.NewClient(bzzapi)
-	)
 	fi, err := os.Stat(expandPath(file))
 	if err != nil {
 		utils.Fatalf("Failed to stat file: %v", err)
@@ -64,7 +87,7 @@ func upload(ctx *cli.Context) {
 		fmt.Println(mhash)
 		return
 	}
-	entry, err := client.UploadFile(file, fi)
+	entry, err = client.UploadFile(file, fi, mimeType)
 	if err != nil {
 		utils.Fatalf("Upload failed: %v", err)
 	}

swarm/api/client/client.go

@@ -89,8 +89,32 @@ func (c *Client) UploadDirectory(dir string, defaultPath string) (string, error)
 	return mhash, err
 }
 
-func (c *Client) UploadFile(file string, fi os.FileInfo) (ManifestEntry, error) {
+func (c *Client) UploadFile(file string, fi os.FileInfo, mimetype_hint string) (ManifestEntry, error) {
+	var mimetype string
 	hash, err := c.uploadFileContent(file, fi)
+	if mimetype_hint != "" {
+		mimetype = mimetype_hint
+		log.Info("Mime type set by override", "mime", mimetype)
+	} else {
+		ext := filepath.Ext(file)
+		log.Info("Ext", "ext", ext, "file", file)
+		if ext != "" {
+			mimetype = mime.TypeByExtension(filepath.Ext(fi.Name()))
+			log.Info("Mime type set by fileextension", "mime", mimetype, "ext", filepath.Ext(file))
+		} else {
+			f, err := os.Open(file)
+			if err == nil {
+				first512 := make([]byte, 512)
+				fread, _ := f.ReadAt(first512, 0)
+				if fread > 0 {
+					mimetype = http.DetectContentType(first512[:fread])
+					log.Info("Mime type set by autodetection", "mime", mimetype)
+				}
+			}
+			f.Close()
+		}
+
+	}
 	m := ManifestEntry{
 		Hash:        hash,
 		ContentType: mime.TypeByExtension(filepath.Ext(fi.Name())),