NAME

       nbdkit-torrent-plugin - serve a BitTorrent file or magnet link over NBD

SYNOPSIS

        nbdkit torrent FILE.torrent|'magnet:?xt=urn:...'
                       [file=DISK.iso] [cache=DIR] ...

DESCRIPTION

       "nbdkit-torrent-plugin" is an nbdkit(1) plugin which lets you serve a single file from
       within a torrent read-only over NBD.  The torrent to download can be a local FILE.torrent
       file, or a magnet link.

       A single torrent contains a collection of files, and by default this plugin serves the
       largest file within the torrent.  For operating system installers this is usually the
       large ISO file and ignores other small files like READMEs.  You can also select a
       particular file by name to serve.

       If you want to turn a file hosted on a web server into an NBD export use
       nbdkit-curl-plugin(1) instead.  If you have a local ISO you can simply serve it using
       nbdkit-file-plugin(1).  If you want to turn a local directory into an ISO use
       nbdkit-iso-plugin(1).

NOTES

       This plugin implements a full-featured BitTorrent client.  BitTorrent clients form a peer-
       to-peer (p2p) network and upload the file to other clients as well as downloading.

       By default the plugin will cache the downloaded torrent into $TMPDIR, potentially
       consuming a lot of disk space.  See the "cache=DIR" parameter for how to control this.

       By default the plugin will consume all available network bandwidth in both download and
       upload directions.  To limit it, set "download-rate-limit" and "upload-rate-limit"
       appropriately.

EXAMPLES

   Boot the Fedora installer
       Choose the right URL from https://torrent.fedoraproject.org/:

        url=https://torrent.fedoraproject.org/torrents/Fedora-Server-dvd-x86_64-32.torrent
        wget $url
        nbdkit -U - torrent Fedora-Server-*.torrent \
               --run 'qemu-system-x86_64 -m 2048 -cdrom $nbd -boot d'

   Boot the Debian installer
       Choose the right URL from https://www.debian.org/CD/torrent-cd/:

        url=https://cdimage.debian.org/debian-cd/current/amd64/bt-dvd/debian-10.4.0-amd64-DVD-1.iso.torrent
        wget $url
        nbdkit -U - torrent debian-*.torrent \
               --run 'qemu-system-x86_64 -m 2048 -cdrom $nbd -boot d'

PARAMETERS

       cache=DIR
           Set a directory which will be used to store the partially downloaded torrent between
           runs.

           This parameter is optional.  If not given then the plugin will create a randomly named
           temporary directory under $TMPDIR, and will attempt to ensure it is cleaned up on exit
           (thus unless you set "cache", no state is saved between runs and the whole torrent
           must be downloaded each time).

       connections-limit=N
           Set limit on number of connections to other peers that this client will open (default
           200).

       download-rate-limit=BITS_PER_SEC
           Set the download rate limit in bits per second.  Usual abbreviations can be used such
           as "download-rate-limit=1M" for 1 megabit per second.  0 means unlimited, which is the
           default.

       file=DISK.iso
           Select the file from within the torrent to serve.

           This parameter is optional.  If not specified then the plugin searches the torrent for
           the largest file and serves that.  This is usually the right thing to do for operating
           system installers and similar because it serves the large .iso file and ignores other
           files like READMEs.

           The parameter is actually a path relative to the root directory of the torrent, so if
           the torrent contains subdirectories you may need to use a path like
           "file=SUBDIR/DISK".  To list all the files within the torrent try running:

            $ nbdkit -fv -U - torrent file.torrent

           and examining the debug output.  As an alternative you can use standard BitTorrent
           tools, eg:

            $ transmission-show file.torrent

       listen-interfaces=IP_ADDRESS:PORT[,IP_ADDRESS:PORT[,...]]
           Listening ports that are opened for accepting incoming connections.  The parameter is
           a comma-separated list of "IP-address:port".

       outgoing-interfaces=IP_ADDRESS[,IP_ADDRESS[,...]]
           Controls which IP address outgoing TCP connections are bound to.  The parameter is a
           comma-separated list of IP addresses.

       [torrent=]FILE.torrent
           Specify a local torrent file.

       [torrent=]magnet:?xt=urn:...
           Specify a magnet link.

           "torrent=" is a magic config key and may be omitted in most cases.  See "Magic
           parameters" in nbdkit(1).

       upload-rate-limit=BITS_PER_SEC
           Set the upload rate limit in bits per second.  Usual abbreviations can be used such as
           "upload-rate-limit=1M" for 1 megabit per second.  0 means unlimited, which is the
           default.

       user-agent=STRING
           Set the user-agent.  The recommended format is "client-name/client-version".

ENVIRONMENT VARIABLES

       "TMPDIR"
           This directory is used to cache the downloaded torrent file (or /var/tmp if not set).
           See also the "cache=DIR" parameter above.

FILES

       $plugindir/nbdkit-torrent-plugin.so
           The plugin.

           Use "nbdkit --dump-config" to find the location of $plugindir.

VERSION

       "nbdkit-torrent-plugin" first appeared in nbdkit 1.22.

SEE ALSO

       nbdkit(1), nbdkit-plugin(3), nbdkit-curl-plugin(1), nbdkit-file-plugin(1),
       nbdkit-iso-plugin(1), nbdkit-readahead-filter(1), nbdkit-scan-filter(1),
       transmission-show(1), https://en.wikipedia.org/wiki/BitTorrent, http://libtorrent.org/.

AUTHORS

       Richard W.M. Jones

COPYRIGHT

       Copyright Red Hat

LICENSE

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       permitted provided that the following conditions are met:

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           conditions and the following disclaimer in the documentation and/or other materials
           provided with the distribution.

       •   Neither the name of Red Hat nor the names of its contributors may be used to endorse
           or promote products derived from this software without specific prior written
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