GoogleContainerTools#3158 - [Jib core] Tar archives with same contents are not reproducible

Author: davidtron

jib-core/src/main/java/com/google/cloud/tools/jib/image/ImageTarball.java

@@ -46,10 +46,12 @@ public class ImageTarball {
   /** File name extension for the layer content files. */
   private static final String LAYER_FILE_EXTENSION = ".tar.gz";
 
+  /** Time that entry is set in the tar. */
+  private static final Instant TAR_ENTRY_MODIFICATION_TIME = Instant.EPOCH;
+
   private final Image image;
   private final ImageReference imageReference;
   private final ImmutableSet<String> allTargetImageTags;
-  private static final Instant TAR_ENTRY_MODIFICATION_TIME = Instant.EPOCH;
 
   /**
    * Instantiate with an {@link Image}.
@@ -91,7 +93,7 @@ private void ociWriteTo(OutputStream out) throws IOException {
       long size = layer.getBlobDescriptor().getSize();
 
       tarStreamBuilder.addBlobEntry(
-          layer.getBlob(), size, "blobs/sha256/" + digest.getHash(), creationTime);
+          layer.getBlob(), size, "blobs/sha256/" + digest.getHash(), TAR_ENTRY_MODIFICATION_TIME);
       manifest.addLayer(size, digest);
     }
 
@@ -103,25 +105,25 @@ private void ociWriteTo(OutputStream out) throws IOException {
     tarStreamBuilder.addByteEntry(
         JsonTemplateMapper.toByteArray(containerConfiguration),
         "blobs/sha256/" + configDescriptor.getDigest().getHash(),
-        creationTime);
+        TAR_ENTRY_MODIFICATION_TIME);
 
     // Adds the manifest to the tarball
     BlobDescriptor manifestDescriptor = Digests.computeDigest(manifest);
     tarStreamBuilder.addByteEntry(
         JsonTemplateMapper.toByteArray(manifest),
         "blobs/sha256/" + manifestDescriptor.getDigest().getHash(),
-        creationTime);
+        TAR_ENTRY_MODIFICATION_TIME);
 
     // Adds the oci-layout and index.json
     tarStreamBuilder.addByteEntry(
         "{\"imageLayoutVersion\": \"1.0.0\"}".getBytes(StandardCharsets.UTF_8),
         "oci-layout",
-        creationTime);
+        TAR_ENTRY_MODIFICATION_TIME);
     OciIndexTemplate index = new OciIndexTemplate();
     // TODO: figure out how to tag with allTargetImageTags
     index.addManifest(manifestDescriptor, imageReference.toStringWithQualifier());
     tarStreamBuilder.addByteEntry(
-        JsonTemplateMapper.toByteArray(index), "index.json", creationTime);
+        JsonTemplateMapper.toByteArray(index), "index.json", TAR_ENTRY_MODIFICATION_TIME);
 
     tarStreamBuilder.writeAsTarArchiveTo(out);
   }
@@ -135,7 +137,10 @@ private void dockerWriteTo(OutputStream out) throws IOException {
       String layerName = layer.getBlobDescriptor().getDigest().getHash() + LAYER_FILE_EXTENSION;
 
       tarStreamBuilder.addBlobEntry(
-          layer.getBlob(), layer.getBlobDescriptor().getSize(), layerName, creationTime);
+          layer.getBlob(),
+          layer.getBlobDescriptor().getSize(),
+          layerName,
+          TAR_ENTRY_MODIFICATION_TIME);
       manifestTemplate.addLayerFile(layerName);
     }
 
@@ -145,7 +150,7 @@ private void dockerWriteTo(OutputStream out) throws IOException {
     tarStreamBuilder.addByteEntry(
         JsonTemplateMapper.toByteArray(containerConfiguration),
         CONTAINER_CONFIGURATION_JSON_FILE_NAME,
-        creationTime);
+        TAR_ENTRY_MODIFICATION_TIME);
 
     // Adds the manifest to tarball.
     for (String tag : allTargetImageTags) {
@@ -154,7 +159,7 @@ private void dockerWriteTo(OutputStream out) throws IOException {
     tarStreamBuilder.addByteEntry(
         JsonTemplateMapper.toByteArray(Collections.singletonList(manifestTemplate)),
         MANIFEST_JSON_FILE_NAME,
-        creationTime);
+        TAR_ENTRY_MODIFICATION_TIME);
 
     tarStreamBuilder.writeAsTarArchiveTo(out);
   }

jib-core/src/main/java/com/google/cloud/tools/jib/tar/TarStreamBuilder.java

@@ -77,7 +77,7 @@ public void addTarArchiveEntry(TarArchiveEntry entry) {
   public void addByteEntry(byte[] contents, String name, Instant modificationTime) {
     TarArchiveEntry entry = new TarArchiveEntry(name);
     entry.setSize(contents.length);
-    entry.setModTime(modTime.getEpochSecond());
+    entry.setModTime(modificationTime.getEpochSecond());
     archiveMap.put(entry, Blobs.from(outputStream -> outputStream.write(contents)));
   }
 
@@ -88,12 +88,12 @@ public void addByteEntry(byte[] contents, String name, Instant modificationTime)
    * @param blob the {@link Blob} to add to the tarball
    * @param size the size (in bytes) of {@code blob}
    * @param name the name of the entry (i.e. filename)
-   * @param modTime the time the entry is created
+   * @param modificationTime the modification time of the entry
    */
-  public void addBlobEntry(Blob blob, long size, String name, Instant modTime) {
+  public void addBlobEntry(Blob blob, long size, String name, Instant modificationTime) {
     TarArchiveEntry entry = new TarArchiveEntry(name);
     entry.setSize(size);
-    entry.setModTime(modTime.getEpochSecond());
+    entry.setModTime(modificationTime.getEpochSecond());
     archiveMap.put(entry, blob);
   }
 }

jib-core/src/test/java/com/google/cloud/tools/jib/tar/TarStreamBuilderTest.java

@@ -97,9 +97,10 @@ public void testToBlob_stringsAndTarArchiveEntriesWithCompression() throws IOExc
 
   @Test
   public void testToBlob_multiByte() throws IOException {
-    testTarStreamBuilder.addByteEntry("日本語".getBytes(StandardCharsets.UTF_8), "test", creationTime);
     testTarStreamBuilder.addByteEntry(
-        "asdf".getBytes(StandardCharsets.UTF_8), "crepecake", creationTime);
+        "日本語".getBytes(StandardCharsets.UTF_8), "test", Instant.EPOCH);
+    testTarStreamBuilder.addByteEntry(
+        "asdf".getBytes(StandardCharsets.UTF_8), "crepecake", Instant.EPOCH);
     testTarStreamBuilder.addBlobEntry(
         Blobs.from("jib"), "jib".getBytes(StandardCharsets.UTF_8).length, "jib", Instant.EPOCH);
 
@@ -124,11 +125,13 @@ public void testToBlob_multiByte() throws IOException {
     Assert.assertEquals("crepecake", headerFile.getName());
     Assert.assertEquals(
         "asdf", new String(ByteStreams.toByteArray(tarArchiveInputStream), StandardCharsets.UTF_8));
+    Assert.assertEquals(Instant.EPOCH, headerFile.getModTime().toInstant());
 
     headerFile = tarArchiveInputStream.getNextTarEntry();
     Assert.assertEquals("jib", headerFile.getName());
     Assert.assertEquals(
         "jib", new String(ByteStreams.toByteArray(tarArchiveInputStream), StandardCharsets.UTF_8));
+    Assert.assertEquals(Instant.EPOCH, headerFile.getModTime().toInstant());
 
     Assert.assertNull(tarArchiveInputStream.getNextTarEntry());
   }
@@ -150,27 +153,27 @@ private void setUpWithTarEntries() {
   /** Creates a TarStreamBuilder using Strings. */
   private void setUpWithStrings() {
     // Prepares a test TarStreamBuilder.
-    testTarStreamBuilder.addByteEntry(fileAContents, "some/path/to/resourceFileA", creationTime);
-    testTarStreamBuilder.addByteEntry(fileBContents, "crepecake", creationTime);
+    testTarStreamBuilder.addByteEntry(fileAContents, "some/path/to/resourceFileA", Instant.EPOCH);
+    testTarStreamBuilder.addByteEntry(fileBContents, "crepecake", Instant.EPOCH);
     testTarStreamBuilder.addTarArchiveEntry(
         new TarArchiveEntry(directoryA.toFile(), "some/path/to"));
     testTarStreamBuilder.addByteEntry(
         fileAContents,
         "some/really/long/path/that/exceeds/100/characters/abcdefghijklmnopqrstuvwxyz0123456789012345678901234567890",
-        creationTime);
+        Instant.EPOCH);
   }
 
   /** Creates a TarStreamBuilder using Strings and TarArchiveEntries. */
   private void setUpWithStringsAndTarEntries() {
     // Prepares a test TarStreamBuilder.
-    testTarStreamBuilder.addByteEntry(fileAContents, "some/path/to/resourceFileA", creationTime);
+    testTarStreamBuilder.addByteEntry(fileAContents, "some/path/to/resourceFileA", Instant.EPOCH);
     testTarStreamBuilder.addTarArchiveEntry(new TarArchiveEntry(fileB.toFile(), "crepecake"));
     testTarStreamBuilder.addTarArchiveEntry(
         new TarArchiveEntry(directoryA.toFile(), "some/path/to"));
     testTarStreamBuilder.addByteEntry(
         fileAContents,
         "some/really/long/path/that/exceeds/100/characters/abcdefghijklmnopqrstuvwxyz0123456789012345678901234567890",
-        creationTime);
+        Instant.EPOCH);
   }
 
   /** Creates a compressed blob from the TarStreamBuilder and verifies it. */
@@ -215,18 +218,21 @@ private void verifyTarArchive(TarArchiveInputStream tarArchiveInputStream) throw
     // Verifies fileB was archived correctly.
     TarArchiveEntry headerFileB = tarArchiveInputStream.getNextTarEntry();
     Assert.assertEquals("crepecake", headerFileB.getName());
+    Assert.assertEquals(Instant.EPOCH, headerFileB.getModTime().toInstant());
     byte[] fileBString = ByteStreams.toByteArray(tarArchiveInputStream);
     Assert.assertArrayEquals(fileBContents, fileBString);
 
     // Verifies directoryA was archived correctly.
     TarArchiveEntry headerDirectoryA = tarArchiveInputStream.getNextTarEntry();
     Assert.assertEquals("some/path/to/", headerDirectoryA.getName());
+    Assert.assertEquals(Instant.EPOCH, headerDirectoryA.getModTime().toInstant());
 
     // Verifies the long file was archived correctly.
     TarArchiveEntry headerFileALong = tarArchiveInputStream.getNextTarEntry();
     Assert.assertEquals(
         "some/really/long/path/that/exceeds/100/characters/abcdefghijklmnopqrstuvwxyz0123456789012345678901234567890",
         headerFileALong.getName());
+    Assert.assertEquals(Instant.EPOCH, headerFileALong);
     byte[] fileALongString = ByteStreams.toByteArray(tarArchiveInputStream);
     Assert.assertArrayEquals(fileAContents, fileALongString);