nbdkit-release-notes-1.20 - Man Page

release notes for nbdkit 1.20

Description

These are the release notes for nbdkit stable release 1.20. This describes the major changes since 1.18.

nbdkit 1.20.0 was released on 2nd May 2020.

Security

There were no security issues found.  All past security issues and information about how to report new ones can be found in nbdkit-security(1).

Plugins

New nbdkit-tmpdisk-plugin(1) is a scriptable “remote tmpfs” for creating temporary filesystems (eg. for thin clients), and also for blank or prepopulated temporary disks.

nbdkit-data-plugin(1) now has support for prepopulating disks with more complex test patterns such as repeated sequences of bytes.

nbdkit-curl-plugin(1) now supports setting a proxy, enabling TCP keepalives, and disabling Nagle’s algorithm.

nbdkit-perl-plugin(1) now supports API version 2.  In particular the full NBD client flags are visible to plugins, along with support for the .get_ready callback.  Also there is a new function Nbdkit::debug which is a wrapper around the nbdkit_debug API.

nbdkit-vddk-plugin(1) drops support for VDDK 5.1.1.  This version was last updated in 2014 and is no longer supported by VMware.  Since this was the last version of VDDK to support i686, 32-bit support is also dropped (Eric Blake).

Language bindings

Plugins may now be written in Golang, see nbdkit-golang-plugin(3) (thanks Dan Berrangé, James Shubin).

OCaml plugins can now access nbdkit_realpath, nbdkit_nanosleep, nbdkit_export_name and nbdkit_shutdown.

Python plugins now transparently support fail-fast zero (Eric Blake).

Filters

New nbdkit-exitlast-filter(1) causes nbdkit to exit after the last client connection.

New nbdkit-limit-filter(1) allows you to limit the number of clients which can simultaneously connect to any plugin.

Server

The --run option now waits for the nbdkit plugin and nbdkit to exit before returning to the caller.  This allows for more predictable clean up in shell scripts using this feature.

nbdkit --dump-config output now includes separate lines for version_major and version_minor, making it easier to find out from shell scripts which version of nbdkit is installed.

nbdkit -s option (which connects to the client over stdin/stdout) now rejects various options that would also try to read from or write to stdin/stdout, for example --dump-plugin or password=- (Eric Blake).

API

New nbdkit_shutdown call which allows plugins to ask for nbdkit to exit.  This is used to implement the new exitlast filter.

New nbdkit_stdio_safe call allows plugins to check if reading from stdin or writing to stdout is safe, eg. if it is safe to read passwords interactively (Eric Blake).

can_* callbacks which return booleans can return any value ≥ 1 to mean true.  Previous versions of nbdkit had inconsistent behaviour if plugins returned anything other than 1 for true (Eric Blake).

Bug fixes

nbdkit-tar-plugin(1) now works and there is a regression test for it.

nbdkit-curl-plugin(1) -D curl.version=1 option now works.

Fixed a rare hang when closing a connection in nbdkit-nbd-plugin(1) (Eric Blake).

Fix compilation on certain platforms with clang (Khem Raj).

Don’t leak $tmpdir from nbdkit-sh-plugin(1) into the --run subcommand.

nbdkit now correctly sets FD_CLOEXEC when using systemd socket activation (Eric Blake).

Documentation

The nbdkit-plugin(3) man page has been overhauled completely to make it easier to follow.  Also we now have documentation for how to compile plugins in various environments which was missing before.

Tests

All valgrind tests now pass.

“Old plugin” tests were added for v1.18.2 on x86-64, and a variety of old plugins compiled on i686.  The i686 plugins will allow us to test for regressions in 32 bit support.

Tests of the nbd plugin should now be stable (Eric Blake).

There is an additional test combining the offset and truncate filters, which tests several corner cases as well as providing tests of error handling between layers.

Build

nbdkit-nbd-plugin(1) now requires libnbd.  (If libnbd is not present at build time then this plugin is not built).  The fallback code in this plugin which made NBD connections by constructing NBD command packets without using libnbd has been removed (Eric Blake).

scripts/git.orderfile has been improved so that commands like git diff and git show display OCaml sources in a natural order with interface first followed by implementation.

Various fixes for MinGW.  Note MinGW / MSYS support is a work in progress and not finished yet (Frank Gu).

Multiple fixes to Haiku build.

awk(1) is no longer required to run the tests.  It was a “hidden” required dependency, but all use of it has now been eliminated.

Internals

There is now an internal utility library for creating vectors/lists of objects, for example lists of strings (common/utils/vector.h).  It is widely used by the server, plugins and filters.

README discusses how to use lcov(1) for code coverage reports.

See Also

nbdkit(1).

Authors

Authors of nbdkit 1.20:

Eric Blake

(33 commits)

Khem Raj

(1 commit)

Richard W.M. Jones

(134 commits)

Frank Gu

(6 commits)

License

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Referenced By

nbdkit(1).

2020-06-29 nbdkit-1.21.13