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Use --numeric-owner when extracting base image

When extracting the base image without --numeric-owner, user and group
names in the tarball are mapped to uid/gid by the host.  This can cause
problems when building an image for some other distro than you're
running yourself.  For example, building an Ubuntu image on openSUSE
ends up with /var/cache/man in the image owned by 'proxy' (uid 13)
instead of 'man' (uid 6), because the host (openSUSE) uses uid 13 for
the 'man' user.  This particular man/proxy discrepancy results in
"fopen: Permission denied" errors when apt-get does its "Processing
triggers for man-db" thing in the Ubuntu system.  I wouldn't be
surprised if there were other kinks caused by this uid/gid mapping
discrepancy too, but that's the one I found so far.

The same thing can also happen with Fedora, but seems to be less likely,
or at least less obvious to me when building Fedora images on openSUSE.
But, IMO, it's better to be safe and just use --numeric-owner on all
base image untarring outside the chroot.

Change-Id: I9da5ac66dd182e7278fe4fee932093f61d35673a
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1 parent 21a81d8 commit 6da49c6d4943865932e52a2f06a11803f082af33 @tserong tserong committed Oct 8, 2013
@@ -58,6 +58,7 @@ else
mv $WORKING/tmp.tar $DIB_IMAGE_CACHE/$BASE_IMAGE_TAR
fi
fi
-# Extract the base image
-sudo tar -C $TARGET_ROOT -xzf $DIB_IMAGE_CACHE/$BASE_IMAGE_TAR
+# Extract the base image (use --numeric-owner to avoid UID/GID mismatch between
+# image tarball and host OS e.g. when building Fedora image on an openSUSE host)
+sudo tar -C $TARGET_ROOT --numeric-owner -xzf $DIB_IMAGE_CACHE/$BASE_IMAGE_TAR
sudo rmdir $TARGET_ROOT/lost+found
@@ -51,6 +51,7 @@ else
mv $WORKING/tmp.tar $DIB_IMAGE_CACHE/$BASE_IMAGE_TAR
fi
fi
-# Extract the base image
-sudo tar -C $TARGET_ROOT -xzf $DIB_IMAGE_CACHE/$BASE_IMAGE_TAR
+# Extract the base image (use --numeric-owner to avoid UID/GID mismatch between
+# image tarball and host OS e.g. when building RHEL image on an openSUSE host)
+sudo tar -C $TARGET_ROOT --numeric-owner -xzf $DIB_IMAGE_CACHE/$BASE_IMAGE_TAR
sudo rmdir $TARGET_ROOT/lost+found
@@ -24,6 +24,7 @@ else
grep "$BASE_IMAGE_FILE" SHA256SUMS.ubuntu.$DIB_RELEASE.$ARCH | sha256sum --check -
popd
fi
-# Extract the base image
-sudo tar -C $TARGET_ROOT -xzf $DIB_IMAGE_CACHE/$BASE_IMAGE_FILE
+# Extract the base image (use --numeric-owner to avoid UID/GID mismatch between
+# image tarball and host OS e.g. when building Ubuntu image on an openSUSE host)
+sudo tar -C $TARGET_ROOT --numeric-owner -xzf $DIB_IMAGE_CACHE/$BASE_IMAGE_FILE
sudo rmdir $TARGET_ROOT/lost+found

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