Merge pull request #2762 from ijc/handle-empty-metadata

Handle empty metadata file better (by ignoring)

src/cmd/linuxkit/run_hyperkit.go

@@ -141,22 +141,11 @@ func runHyperKit(args []string) {
 		log.Fatalf("Could not create state directory: %v", err)
 	}
 
-	if *data != "" {
+	metadataPaths, err := CreateMetadataISO(*state, *data)
-		var d []byte
+	if err != nil {
-		if _, err := os.Stat(*data); os.IsNotExist(err) {
+		log.Fatalf("%v", err)
-			d = []byte(*data)
-		} else {
-			d, err = ioutil.ReadFile(*data)
-			if err != nil {
-				log.Fatalf("Cannot read user data: %v", err)
-			}
-		}
-		isoPath := filepath.Join(*state, "data.iso")
-		if err := WriteMetadataISO(isoPath, d); err != nil {
-			log.Fatalf("Cannot write user data ISO: %v", err)
-		}
-		isoPaths = append(isoPaths, isoPath)
 	}
+	isoPaths = append(isoPaths, metadataPaths...)
 
 	// Create UUID for VPNKit or reuse an existing one from state dir. IP addresses are
 	// assigned to the UUID, so to get the same IP we have to store the initial UUID. If

src/cmd/linuxkit/run_qemu.go

@@ -223,22 +223,11 @@ func runQemu(args []string) {
 		isoPaths = append(isoPaths, path)
 	}
 
-	if *data != "" {
+	metadataPaths, err := CreateMetadataISO(*state, *data)
-		var d []byte
+	if err != nil {
-		if _, err := os.Stat(*data); os.IsNotExist(err) {
+		log.Fatalf("%v", err)
-			d = []byte(*data)
-		} else {
-			d, err = ioutil.ReadFile(*data)
-			if err != nil {
-				log.Fatalf("Cannot read user data: %v", err)
-			}
-		}
-		isoPath := filepath.Join(*state, "data.iso")
-		if err := WriteMetadataISO(isoPath, d); err != nil {
-			log.Fatalf("Cannot write user data ISO: %v", err)
-		}
-		isoPaths = append(isoPaths, isoPath)
 	}
+	isoPaths = append(isoPaths, metadataPaths...)
 
 	for i, d := range disks {
 		id := ""

src/cmd/linuxkit/util.go

@@ -3,7 +3,9 @@ package main
 import (
 	"bufio"
 	"fmt"
+	"io/ioutil"
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 )
@@ -252,3 +254,27 @@ func NewPublishedPort(publish string) (PublishedPort, error) {
 	p.Protocol = protocol
 	return p, nil
 }
+
+// CreateMetadataISO writes the provided meta data to an iso file in the given state directory
+func CreateMetadataISO(state, data string) ([]string, error) {
+	if data == "" {
+		return []string{}, nil
+	}
+
+	var d []byte
+	if st, err := os.Stat(data); os.IsNotExist(err) {
+		d = []byte(data)
+	} else if st.Size() == 0 {
+		return []string{}, nil
+	} else {
+		d, err = ioutil.ReadFile(data)
+		if err != nil {
+			return nil, fmt.Errorf("Cannot read user data: %v", err)
+		}
+	}
+	isoPath := filepath.Join(state, "data.iso")
+	if err := WriteMetadataISO(isoPath, d); err != nil {
+		return nil, fmt.Errorf("Cannot write user data ISO: %v", err)
+	}
+	return []string{isoPath}, nil
+}

src/cmd/linuxkit/vendor.conf

@@ -21,7 +21,7 @@ github.com/packethost/packngo 131798f2804a1b3e895ca98047d56f0d7e094e2a
 github.com/pmezard/go-difflib v1.0.0
 github.com/radu-matei/azure-sdk-for-go 3b12823551999669c9a325a32472508e0af7978e
 github.com/radu-matei/azure-vhd-utils e52754d5569d2a643a7775f72ff2a6cf524f4c25
-github.com/rn/iso9660wrap 4606f848a055435cdef85305960b0e1bb788d506
+github.com/rn/iso9660wrap baf8d62ad3155152b488d5ff9d4f2b9bb0d6986a
 github.com/sirupsen/logrus 1.0.2
 github.com/stretchr/testify v1.1.4
 github.com/vmware/govmomi 6f8ebd89d521d9f9af7a6c2219c4deee511020dd

src/cmd/linuxkit/vendor/github.com/rn/iso9660wrap/iso9660wrap.go

@@ -12,134 +12,6 @@ import (
 	"time"
 )
 
-const reservedAreaData string = `
-Once upon a midnight dreary, while I pondered, weak and weary,
-Over many a quaint and curious volume of forgotten lore—
-    While I nodded, nearly napping, suddenly there came a tapping,
-As of some one gently rapping, rapping at my chamber door.
-“’Tis some visitor,” I muttered, “tapping at my chamber door—
-            Only this and nothing more.”
-
- Ah, distinctly I remember it was in the bleak December;
-And each separate dying ember wrought its ghost upon the floor.
-    Eagerly I wished the morrow;—vainly I had sought to borrow
-    From my books surcease of sorrow—sorrow for the lost Lenore—
-For the rare and radiant maiden whom the angels name Lenore—
-            Nameless here for evermore.
-
-    And the silken, sad, uncertain rustling of each purple curtain
-Thrilled me—filled me with fantastic terrors never felt before;
-    So that now, to still the beating of my heart, I stood repeating
-    “’Tis some visitor entreating entrance at my chamber door—
-Some late visitor entreating entrance at my chamber door;—
-            This it is and nothing more.”
-
-    Presently my soul grew stronger; hesitating then no longer,
-“Sir,” said I, “or Madam, truly your forgiveness I implore;
-    But the fact is I was napping, and so gently you came rapping,
-    And so faintly you came tapping, tapping at my chamber door,
-That I scarce was sure I heard you”—here I opened wide the door;—
-            Darkness there and nothing more.
-
-    Deep into that darkness peering, long I stood there wondering, fearing,
-Doubting, dreaming dreams no mortal ever dared to dream before;
-    But the silence was unbroken, and the stillness gave no token,
-    And the only word there spoken was the whispered word, “Lenore?”
-This I whispered, and an echo murmured back the word, “Lenore!”—
-            Merely this and nothing more.
-
-    Back into the chamber turning, all my soul within me burning,
-Soon again I heard a tapping somewhat louder than before.
-    “Surely,” said I, “surely that is something at my window lattice;
-      Let me see, then, what thereat is, and this mystery explore—
-Let my heart be still a moment and this mystery explore;—
-            ’Tis the wind and nothing more!”
-
-    Open here I flung the shutter, when, with many a flirt and flutter,
-In there stepped a stately Raven of the saintly days of yore;
-    Not the least obeisance made he; not a minute stopped or stayed he;
-    But, with mien of lord or lady, perched above my chamber door—
-Perched upon a bust of Pallas just above my chamber door—
-            Perched, and sat, and nothing more.
-
-Then this ebony bird beguiling my sad fancy into smiling,
-By the grave and stern decorum of the countenance it wore,
-“Though thy crest be shorn and shaven, thou,” I said, “art sure no craven,
-Ghastly grim and ancient Raven wandering from the Nightly shore—
-Tell me what thy lordly name is on the Night’s Plutonian shore!”
-            Quoth the Raven “Nevermore.”
-
-    Much I marvelled this ungainly fowl to hear discourse so plainly,
-Though its answer little meaning—little relevancy bore;
-    For we cannot help agreeing that no living human being
-    Ever yet was blessed with seeing bird above his chamber door—
-Bird or beast upon the sculptured bust above his chamber door,
-            With such name as “Nevermore.”
-
-    But the Raven, sitting lonely on the placid bust, spoke only
-That one word, as if his soul in that one word he did outpour.
-    Nothing farther then he uttered—not a feather then he fluttered—
-    Till I scarcely more than muttered “Other friends have flown before—
-On the morrow he will leave me, as my Hopes have flown before.”
-            Then the bird said “Nevermore.”
-
-    Startled at the stillness broken by reply so aptly spoken,
-“Doubtless,” said I, “what it utters is its only stock and store
-    Caught from some unhappy master whom unmerciful Disaster
-    Followed fast and followed faster till his songs one burden bore—
-Till the dirges of his Hope that melancholy burden bore
-            Of ‘Never—nevermore’.”
-
-    But the Raven still beguiling all my fancy into smiling,
-Straight I wheeled a cushioned seat in front of bird, and bust and door;
-    Then, upon the velvet sinking, I betook myself to linking
-    Fancy unto fancy, thinking what this ominous bird of yore—
-What this grim, ungainly, ghastly, gaunt, and ominous bird of yore
-            Meant in croaking “Nevermore.”
-
-    This I sat engaged in guessing, but no syllable expressing
-To the fowl whose fiery eyes now burned into my bosom’s core;
-    This and more I sat divining, with my head at ease reclining
-    On the cushion’s velvet lining that the lamp-light gloated o’er,
-But whose velvet-violet lining with the lamp-light gloating o’er,
-            She shall press, ah, nevermore!
-
-    Then, methought, the air grew denser, perfumed from an unseen censer
-Swung by Seraphim whose foot-falls tinkled on the tufted floor.
-    “Wretch,” I cried, “thy God hath lent thee—by these angels he hath sent thee
-    Respite—respite and nepenthe from thy memories of Lenore;
-Quaff, oh quaff this kind nepenthe and forget this lost Lenore!”
-            Quoth the Raven “Nevermore.”
-
-    “Prophet!” said I, “thing of evil!—prophet still, if bird or devil!—
-Whether Tempter sent, or whether tempest tossed thee here ashore,
-    Desolate yet all undaunted, on this desert land enchanted—
-    On this home by Horror haunted—tell me truly, I implore—
-Is there—is there balm in Gilead?—tell me—tell me, I implore!”
-            Quoth the Raven “Nevermore.”
-
-    “Prophet!” said I, “thing of evil!—prophet still, if bird or devil!
-By that Heaven that bends above us—by that God we both adore—
-    Tell this soul with sorrow laden if, within the distant Aidenn,
-    It shall clasp a sainted maiden whom the angels name Lenore—
-Clasp a rare and radiant maiden whom the angels name Lenore.”
-            Quoth the Raven “Nevermore.”
-
-    “Be that word our sign of parting, bird or fiend!” I shrieked, upstarting—
-“Get thee back into the tempest and the Night’s Plutonian shore!
-    Leave no black plume as a token of that lie thy soul hath spoken!
-    Leave my loneliness unbroken!—quit the bust above my door!
-Take thy beak from out my heart, and take thy form from off my door!”
-            Quoth the Raven “Nevermore.”
-
-    And the Raven, never flitting, still is sitting, still is sitting
-On the pallid bust of Pallas just above my chamber door;
-    And his eyes have all the seeming of a demon’s that is dreaming,
-    And the lamp-light o’er him streaming throws his shadow on the floor;
-And my soul from out that shadow that lies floating on the floor
-            Shall be lifted—nevermore!
-`
-
 func Panicf(format string, v ...interface{}) {
 	panic(fmt.Errorf(format, v...))
 }
@@ -159,9 +31,6 @@ func WriteFile(outfh, infh *os.File) error {
 	if err != nil {
 		return err
 	}
-	if fileSize == 0 {
-		return fmt.Errorf("input file must be at least 1 byte in size")
-	}
 	filename = strings.ToUpper(filename)
 	if !filenameSatisfiesISOConstraints(filename) {
 		return fmt.Errorf("Input file name %s does not satisfy the ISO9660 character set constraints", filename)
@@ -177,27 +46,16 @@ func WriteFile(outfh, infh *os.File) error {
 }
 
 // WriteBuffer writes the contents of buf to an iso at outfh with the name provided
-func WriteBuffer(outfh *os.File, buf []byte, filename string) error {
+func WriteBuffer(outfh io.Writer, buf []byte, filename string) error {
 	fileSize := uint32(len(buf))
-	if fileSize == 0 {
-		return fmt.Errorf("input buffer must be at least 1 byte in size")
-	}
 	r := bytes.NewReader(buf)
 
 	// reserved sectors
 	reservedAreaLength := int64(16 * SectorSize)
-	_, err := outfh.Write([]byte(reservedAreaData))
+	_, err := outfh.Write(make([]byte,reservedAreaLength))
 	if err != nil {
 		return fmt.Errorf("could not write to output file: %s", err)
 	}
-	err = outfh.Truncate(reservedAreaLength)
-	if err != nil {
-		return fmt.Errorf("could not truncate output file: %s", err)
-	}
-	_, err = outfh.Seek(reservedAreaLength, os.SEEK_SET)
-	if err != nil {
-		return fmt.Errorf("could not seek output file: %s", err)
-	}
 
 	err = nil
 	func() {