search for: path_inside_tar

...kit-tar-filter.pod new file mode 100644 index 00000000..85968668 --- /dev/null +++ b/filters/tar/nbdkit-tar-filter.pod @@ -0,0 +1,108 @@ +=head1 NAME + +nbdkit-tar-filter - read and write files inside tar files without unpacking + +=head1 SYNOPSIS + + nbdkit file FILENAME.tar --filter=tar tar-entry=PATH_INSIDE_TAR + +=head1 EXAMPLES + +=head2 Serve a single file inside a tarball + + nbdkit file file.tar --filter=tar tar-entry=some/disk.img + guestfish --format=raw -a nbd://localhost + +=head2 Opening a disk image inside an OVA file + +The popular "Open Virtual Appliance" (OVA) format is really an +...

...gt; wrapper.c | 2 +- > .gitignore | 1 - > README | 4 +- > 13 files changed, 427 insertions(+), 163 deletions(-) > > > - nbdkit tar tar=FILENAME.tar file=PATH_INSIDE_TAR > + nbdkit tar [tar=]FILENAME.tar file=PATH_INSIDE_TAR I'm considering a followup patch to allow file=exportname as a magic filename, similarly to how we did in the ext2 filter. > +=item B<file=>PATH_INSIDE_TAR > + > +The path of the file inside the tarball to serve. This...

For review only, this needs some clean up and more tests. My eyes are going cross-eyed looking at the calculate_offset_of_entry function, so time to take a break ... Rich.

.....589e114b 100644 --- a/plugins/tar/tar.pl +++ b/plugins/tar/nbdkit-tar-plugin.pod @@ -1,21 +1,16 @@ -#!@sbindir@/nbdkit perl -# -*- perl -*- - -=pod - =head1 NAME nbdkit-tar-plugin - read and write files inside tar files without unpacking =head1 SYNOPSIS - nbdkit tar tar=FILENAME.tar file=PATH_INSIDE_TAR + nbdkit tar [tar=]FILENAME.tar file=PATH_INSIDE_TAR =head1 EXAMPLES =head2 Serve a single file inside a tarball - nbdkit tar tar=file.tar file=some/disk.img + nbdkit tar file.tar file=some/disk.img guestfish --format=raw -a nbd://localhost =head2 Opening a disk image inside an OVA fil...

For context see these threads: https://lists.gnu.org/archive/html/qemu-discuss/2020-06/threads.html#00053 https://lists.gnu.org/archive/html/qemu-block/2020-06/threads.html#01496 Rich.

This patch series cleans up some issues with nbdkit-tar-filter and (in patch 3) implements a new tar-limit feature which limits how much of the tar file we will read to find the entry within the tar file that we will serve. This protects against the case where a tar file is presented that contains much content at the front that we must iterate over (and download) before we get to the entry we are