similar to: [libnbd PATCH v2] nbdsh: Catch nbd.Error from -c arguments

v1 was here: https://listman.redhat.com/archives/libguestfs/2022-October/030216.html Since then, I've incorporated changes based on Rich's feedback: swap order of patches 2 and 3 less change in patch 1 (including no unsafe eval(%s) for --uri) in patch 2, include -c in list of snippets to store, and use dict of lambdas to map back to the desired action Eric Blake (3): nbdsh:

When using nbdsh for scripting, it is convenient to let nbdsh fail with status 1 when encountering an API failure. However, doing so by letting the nbd.Error exception leak all the way causes ABRT (on Fedora 32 at least) to assume the program crashed from a programming error, and needlessly complicates clients to have to add try: blocks. Better is if nbdsh itself prints the same stack trace that

On Tue, Sep 22, 2020 at 11:15:39AM -0500, Eric Blake wrote: > + try: > + for c in args.command: > + if c != '-': > + exec(c, d, d) > + else: > + exec(sys.stdin.read(), d, d) > + except nbd.Error as ex: > + if os.environ.get("LIBNBD_DEBUG", "0")

We decided to not request the "base:allocation" context by default (if a client wants to use block_status on a different context, then they'd have to get any default request out of the way); however, block status is useless without at least one meta context. This adds a convenience knob for requesting that, and has the nice benefit of working with the --connect command line option

Ultimately, I'd like to add a unit test covering our recent fix for handling globals from consecutive -c, but let's start with a simple test that --help output is sane. Sanity includes a mention of the man page for more details (similar to nbdkit --help, although I couldn't figure out how to make python's argparse output that sentence last). --- python/nbdsh.py | 3 ++-

This makes it consistent with other nbd_is_* and nbd_can_* APIs. Suggested by Thomas Haller. --- docs/libnbd.pod | 2 +- examples/batched-read-write.c | 2 +- examples/simple-reads-and-writes.c | 2 +- examples/threaded-reads-and-writes.c | 2 +- generator/generator | 2 +- lib/flags.c | 2 +- lib/rw.c

nbdsh has some advantages over qemu-io: - scriptable - allows us to more finely control NBD commands, such as making subsector-sized requests and controlling how many commands are sent on the wire - can write controlled patterns - can read NBD export flags --- README | 2 ++ tests/Makefile.am | 5 +++-- tests/test-error0.sh | 13 +++++++------

Right now, libnbd has refused to issue a command not advertised as supported by a server, mainly because the NBD protocol does not guarantee what the server will do, and libnbd would rather stay in sync with the server than drop the connection. However, for integration purposes, it can be handy to coerce libnbd into sending something to see how the server will react (whether it be an extension

Typing nbdsh --con (the minimum to get an unambiguous prefix for --connect, different from --command) is annoying compared to having a short option. Since it takes a URI as an argument, using -u seems like a reasonable mnemonic. --- sh/nbdsh.pod | 6 ++++-- python/nbdsh.py | 2 +- sh/test-context.sh | 8 ++++---- sh/test-pattern.sh | 2 +- 4 files changed, 10 insertions(+), 8

I'm out of time this weekend, but while trying to write a test for an nbdkit bug fix (a nasty assertion failure when the client disconnects uncleanly without NBD_CMD_DISC, which is what nbdcopy does if it gets an EIO read response from the server), I realized it is extremely hard to trigger this using nbdsh, but easy to do in C or the Go bindings. In the Go bindings, we intentionally coded

We want some testsuite coverage of handling non-1 .can_flush values. The only in-tree plugin with this property is nbd-standalone, but it doesn't get frequently tested, not to mention that the next patch will change it to work with older nbdkit. Signed-off-by: Eric Blake <eblake@redhat.com> --- work in progress: currently compiles but fails during test; posting it now to show my

Test that we can script the read of a specific pattern from nbdkit. Also, test that we can concatenate global functions through consecutive -c. This test fails if commit d6cbd130 is reverted. --- sh/Makefile.am | 5 ++++- sh/test-dump.sh | 45 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+), 1 deletion(-) create mode 100755 sh/test-dump.sh diff --git

On Tue, Jan 31, 2023 at 01:33:25PM +0200, Nir Soffer wrote: > On Tue, Jan 31, 2023 at 12:34 AM Richard W.M. Jones <rjones at redhat.com> wrote: > > > > On Fri, Nov 04, 2022 at 04:18:31PM -0500, Eric Blake wrote: > > > Document all options in --help output. If -n is not in use, then > > > enhance the banner to print the current state of h, and further tailor

Typing nbdsh --con (the minimum to get an unambiguous prefix for --connect, different from --command) is annoying compared to having a short option. Since it takes a URI as an argument, using -u/--uri is a nicer mnemonic. We still accept --connect for back-compat, and document it in the man page, but omit it from --help as the new spelling is nicer all around. --- Here's what things evolved

On Tue, Jan 31, 2023 at 11:52:27AM +0000, Richard W.M. Jones wrote: > On Tue, Jan 31, 2023 at 01:33:25PM +0200, Nir Soffer wrote: > > On Tue, Jan 31, 2023 at 12:34 AM Richard W.M. Jones <rjones at redhat.com> wrote: > > > > > > On Fri, Nov 04, 2022 at 04:18:31PM -0500, Eric Blake wrote: > > > > Document all options in --help output. If -n is not in

Similar to --base-allocation, this is a common enough configuration that cannot be performed with -c when using --uri, but which makes life easier in scripting. And like --base-allocation, I'm starting with only a long option spelling, rather than burning a short option letter. --- sh/nbdsh.pod | 21 +++++++++++++++++++-- python/nbdsh.py | 6 ++++++ sh/test-context.sh | 32

Very much a work in progress as there are still many tests using qemu-io which are candidates for conversion. You'll notice at the end of test-full.sh that the new test has some duplicated code which looks as if it ought to be refactored into a Python function. When I tried to do that, I got loads of strange Python problems which may indicate bugs in nbdsh itself or problems with my

On Fri, Feb 24, 2023 at 04:41:20PM -0600, Eric Blake wrote: > I'm out of time this weekend, but while trying to write a test for an > nbdkit bug fix (a nasty assertion failure when the client disconnects > uncleanly without NBD_CMD_DISC, which is what nbdcopy does if it gets > an EIO read response from the server), I realized it is extremely hard > to trigger this using nbdsh,

Use the just-added nbd_opt_list_meta_context() API to give more details about each export (matching what 'qemu-nbd --list' already does). Note that this requires some shuffling: listing meta exports requires being in opt mode, but is easiest to do in list_one_export(), which requires setting opt_mode in more code paths, and deferring ready mode until the last possible minute during

I'm pleased to announce the releases of libnbd 1.2 and nbdkit 1.16. These are a high performance Network Block Device (NBD) client library and server. Key features of libnbd: * Synchronous API for ease of use. * Asynchronous API for writing non-blocking, multithreaded clients. You can mix both APIs freely. * High performance. * Minimal dependencies for the basic library. *