Our virCommand module allows us to set a pidfile for commands we
want to spawn. The caller constructs the string of pidfile path
and then uses virCommandSetPidFile() to tell the module to write
the pidfile once the command is ran. This usually works, but has
two flaws:
1) the child process does not hold the pidfile open & locked.
Therefore, the caller (or anybody else) can't use our fancy
virPidFileForceCleanupPath() function to kill the command
afterwards. Also, for everybody else on the system it's
needlessly harder to check if the pid from the pidfile is still
alive or not.
2) if the caller ever makes a mistake and passes the same pidfile
path for two different commands, the start of the second command
will overwrite the pidfile even though the first command might
still be running.
NOTE that this temporarily renders some command spawning
unusable, specifically those code patterns where both
virCommandSetPidFile() is used together with instructing spawned
command to acquire pidfile itself. Fortunately, there is only one
occurrence of such pattern and it is in
qemuProcessStartManagedPRDaemon(). This is fixed in next commit.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
The OOM handling requires special build time options which we never
enable in our CI. Even once enabled the tests are incredibly slow and
typically require manual inspection of the results to weed out false
positives.
Since there was previous agreement to switch to abort on OOM in libvirt
code, there's no point continuing to keep the unused OOM testing code.
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Libvirtd has long had integration with avahi for advertising libvirtd
using mDNS when TCP/TLS listening is enabled. For a long time the
virt-manager application had support for auto-detecting libvirtds
on the local network using mDNS, but this was removed last year
commit fc8f8d5d7e3ba80a0771df19cf20e84a05ed2422
Author: Cole Robinson <crobinso@redhat.com>
Date: Sat Oct 6 20:55:31 2018 -0400
connect: Drop avahi support
Libvirtd can advertise itself over avahi. The feature is disabled by
default though and in practice I hear of no one actually using it
and frankly I don't think it's all that useful
The 'Open Connection' wizard has a disproportionate amount of code
devoted to this feature, but I don't think it's useful or worth
maintaining, so let's drop it
I've never heard of any other applications having support for using
mDNS to detect libvirtd instances. Though it is theoretically possible
something exists out there, it is clearly going to be a niche use case
in the virt ecosystem as a whole.
By removing avahi integration we can cut down the dependency chain for
the basic libvirtd install and reduce our code maint burden.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The QEMU command line arguments are very long and currently all written
on a single line to /var/log/libvirt/qemu/$GUEST.log. This introduces
logic to add line breaks after every env variable and "-" optional
argument, and every positional argument. This will create a clearer log
file, which will in turn present better in bug reports when people cut +
paste from the log into a bug comment.
An example log file entry now looks like this:
2018-12-14 12:57:03.677+0000: starting up libvirt version: 5.0.0, qemu version: 3.0.0qemu-3.0.0-1.fc29, kernel: 4.19.5-300.fc29.x86_64, hostname: localhost.localdomain
LC_ALL=C \
PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin \
HOME=/home/berrange \
USER=berrange \
LOGNAME=berrange \
QEMU_AUDIO_DRV=none \
/usr/bin/qemu-system-ppc64 \
-name guest=guest,debug-threads=on \
-S \
-object secret,id=masterKey0,format=raw,file=/home/berrange/.config/libvirt/qemu/lib/domain-33-guest/master-key.aes \
-machine pseries-2.10,accel=tcg,usb=off,dump-guest-core=off \
-m 1024 \
-realtime mlock=off \
-smp 1,sockets=1,cores=1,threads=1 \
-uuid c8a74977-ab18-41d0-ae3b-4041c7fffbcd \
-display none \
-no-user-config \
-nodefaults \
-chardev socket,id=charmonitor,fd=23,server,nowait \
-mon chardev=charmonitor,id=monitor,mode=control \
-rtc base=utc \
-no-shutdown \
-boot strict=on \
-device qemu-xhci,id=usb,bus=pci.0,addr=0x1 \
-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x2 \
-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
-msg timestamp=on
2018-12-14 12:57:03.730+0000: shutting down, reason=failed
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Suggested-by: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
The HTML5 doctype is simply
<!DOCTYPE html>
no DTD is present because HTML5 is no longer defined as an
extension of SGML.
XSL has no way to natively output a doctype without a public
or system identifier, so we have to use an <xsl:text> hack
instead.
See also
https://dev.w3.org/html5/html-author/#doctype-declaration
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The 'name' attribute on <a...> elements is deprecated in favour
of the 'id' attribute which is allowed on any element. HTML5
drops 'name' support entirely.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The <pre/> section is rendered as-is on the page. That is, if all
the lines are prefixed with 4 spaces the rendered page will also
have them. Problem is if we put a box around such <pre/> because
the content might not fix into it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The <pre/> section is rendered as-is on the page. That is, if all
the lines are prefixed with 4 spaces the rendered page will also
have them. Problem is if we put a box around such <pre/> because
the content might not fix into it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The <pre/> section is rendered as-is on the page. That is, if all
the lines are prefixed with 4 spaces the rendered page will also
have them. Problem is if we put a box around such <pre/> because
the content might not fix into it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
I was asked the other day what's event loop and how libvirt uses
it. Well, I haven't found any good sources on the Internet so I
thought of writing the documentation on my own.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Auditing all callers of virCommandRun and virCommandWait that
passed a non-NULL pointer for exit status turned up some
interesting observations. Many callers were merely passing
a pointer to avoid the overall command dying, but without
caring what the exit status was - but these callers would
be better off treating a child death by signal as an abnormal
exit. Other callers were actually acting on the status, but
not all of them remembered to filter by WIFEXITED and convert
with WEXITSTATUS; depending on the platform, this can result
in a status being reported as 256 times too big. And among
those that correctly parse the output, it gets rather verbose.
Finally, there were the callers that explicitly checked that
the status was 0, and gave their own message, but with fewer
details than what virCommand gives for free.
So the best idea is to move the complexity out of callers and
into virCommand - by default, we return the actual exit status
already cleaned through WEXITSTATUS and treat signals as a
failed command; but the few callers that care can ask for raw
status and act on it themselves.
* src/util/vircommand.h (virCommandRawStatus): New prototype.
* src/libvirt_private.syms (util/command.h): Export it.
* docs/internals/command.html.in: Document it.
* src/util/vircommand.c (virCommandRawStatus): New function.
(virCommandWait): Adjust semantics.
* tests/commandtest.c (test1): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Adjust callers.
* src/access/viraccessdriverpolkit.c (virAccessDriverPolkitCheck):
Likewise.
* src/fdstream.c (virFDStreamCloseInt): Likewise.
* src/lxc/lxc_process.c (virLXCProcessStart): Likewise.
* src/qemu/qemu_command.c (qemuCreateInBridgePortWithHelper):
Likewise.
* src/xen/xen_driver.c (xenUnifiedXendProbe): Simplify.
* tests/reconnect.c (mymain): Likewise.
* tests/statstest.c (mymain): Likewise.
* src/bhyve/bhyve_process.c (virBhyveProcessStart)
(virBhyveProcessStop): Don't overwrite virCommand error.
* src/libvirt.c (virConnectAuthGainPolkit): Likewise.
* src/openvz/openvz_driver.c (openvzDomainGetBarrierLimit)
(openvzDomainSetBarrierLimit): Likewise.
* src/util/virebtables.c (virEbTablesOnceInit): Likewise.
* src/util/viriptables.c (virIpTablesOnceInit): Likewise.
* src/util/virnetdevveth.c (virNetDevVethCreate): Fix debug
message.
* src/qemu/qemu_capabilities.c (virQEMUCapsInitQMP): Add comment.
* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSINodeUpdate): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
The previous OOM testing support would re-run the entire "main"
method each iteration, failing a different malloc each time.
When a test suite has 'n' allocations, the number of repeats
requires is (n * (n + 1) ) / 2. This gets very large, very
quickly.
This new OOM testing support instead integrates at the
virtTestRun level, so each individual test case gets repeated,
instead of the entire test suite. This means the values of
'n' are orders of magnitude smaller.
The simple usage is
$ VIR_TEST_OOM=1 ./qemuxml2argvtest
...
29) QEMU XML-2-ARGV clock-utc ... OK
Test OOM for nalloc=36 .................................... OK
30) QEMU XML-2-ARGV clock-localtime ... OK
Test OOM for nalloc=36 .................................... OK
31) QEMU XML-2-ARGV clock-france ... OK
Test OOM for nalloc=38 ...................................... OK
...
the second lines reports how many mallocs have to be failed, and thus
how many repeats of the test will be run.
If it crashes, then running under valgrind will often show the problem
$ VIR_TEST_OOM=1 ../run valgrind ./qemuxml2argvtest
When debugging problems it is also helpful to select an individual
test case
$ VIR_TEST_RANGE=30 VIR_TEST_OOM=1 ../run valgrind ./qemuxml2argvtest
When things get really tricky, it is possible to request that just
specific allocs are failed. eg to fail allocs 5 -> 12, use
$ VIR_TEST_RANGE=30 VIR_TEST_OOM=1:5-12 ../run valgrind ./qemuxml2argvtest
In the worse case, you might want to know the stack trace of the
alloc which was failed then VIR_TEST_OOM_TRACE can be set. If it
is set to 1 then it will only print if it thinks a mistake happened.
This is often not reliable, so setting it to 2 will make it print
the stack trace for every alloc that is failed.
$ VIR_TEST_OOM_TRACE=2 VIR_TEST_RANGE=30 VIR_TEST_OOM=1:5-5 ../run valgrind ./qemuxml2argvtest
30) QEMU XML-2-ARGV clock-localtime ... OK
Test OOM for nalloc=36 !virAllocN
/home/berrange/src/virt/libvirt/src/util/viralloc.c:180
virHashCreateFull
/home/berrange/src/virt/libvirt/src/util/virhash.c:144
virDomainDefParseXML
/home/berrange/src/virt/libvirt/src/conf/domain_conf.c:11745
virDomainDefParseNode
/home/berrange/src/virt/libvirt/src/conf/domain_conf.c:12646
virDomainDefParse
/home/berrange/src/virt/libvirt/src/conf/domain_conf.c:12590
testCompareXMLToArgvFiles
/home/berrange/src/virt/libvirt/tests/qemuxml2argvtest.c:106
virtTestRun
/home/berrange/src/virt/libvirt/tests/testutils.c:250
mymain
/home/berrange/src/virt/libvirt/tests/qemuxml2argvtest.c:418 (discriminator 2)
virtTestMain
/home/berrange/src/virt/libvirt/tests/testutils.c:750
??
??:0
_start
??:?
FAILED
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Merge the virCommandPreserveFD / virCommandTransferFD methods
into a single virCommandPasFD method, and use a new
VIR_COMMAND_PASS_FD_CLOSE_PARENT to indicate their difference
in behaviour
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The rule generating the HTML docs passing the --html flag
to xsltproc. This makes it use the legacy HTML parser, which
either ignores or tries to fix all sorts of broken XML tags.
There's no reason why we should be writing broken XML in
the first place, so removing --html and adding the XHTML
doctype to all files forces us to create good XML.
This adds the XHTML doc type and fixes many, many XML tag
problems it exposes.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
http://www.uhv.edu/ac/newsletters/writing/grammartip2009.07.01.htm
(and several other sites) give hints that 'onto' is best used if
you can also add 'up' just before it and still make sense. In many
cases in the code base, we really want the two-word form, or even
a simplification to just 'on' or 'to'.
* docs/hacking.html.in: Use correct 'on to'.
* python/libvirt-override.c: Likewise.
* src/lxc/lxc_controller.c: Likewise.
* src/util/virpci.c: Likewise.
* daemon/THREADS.txt: Use simpler 'on'.
* docs/formatdomain.html.in: Better usage.
* docs/internals/rpc.html.in: Likewise.
* src/conf/domain_event.c: Likewise.
* src/rpc/virnetclient.c: Likewise.
* tests/qemumonitortestutils.c: Likewise.
* HACKING: Regenerate.
Signed-off-by: Eric Blake <eblake@redhat.com>
Sometimes, its easier to run children with 2>&1 in shell notation,
and just deal with stdout and stderr interleaved. This was already
possible for fd handling; extend it to also work when doing string
capture of a child process.
* docs/internals/command.html.in: Document this.
* src/util/command.c (virCommandSetErrorBuffer): Likewise.
(virCommandRun, virExecWithHook): Implement it.
* tests/commandtest.c (test14): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Use new command
feature.
Define two new RPC message types VIR_NET_CALL_WITH_FDS and
VIR_NET_REPLY_WITH_FDS. These message types are equivalent
to VIR_NET_CALL and VIR_NET_REPLY, except that between the
message header, and payload there is a 32-bit integer field
specifying how many file descriptors have been passed.
The actual file descriptors are sent/recv'd out of band.
* src/rpc/virnetmessage.c, src/rpc/virnetmessage.h,
src/libvirt_private.syms: Add support for handling
passed file descriptors
* src/rpc/virnetprotocol.x: Extend protocol for FD
passing
* remote.html.in: Remove obsolete notes about internals of the
RPC protocol
* internals/rpc.html.in: Extensive docs on RPC protocol/API
* sitemap.html.in: Add new page
When using virCommandRunAsync and saving the pid for later, it
is useful to be able to reap that pid in the same way that it
would have been auto-reaped by virCommand if we had passed
NULL for the pid argument in the first place.
* src/util/command.c (virPidWait, virPidAbort): New functions,
created from...
(virCommandWait, virCommandAbort): ...bodies of these.
(includes): Drop duplicate <stdlib.h>. Ensure that our pid_t
assumptions hold.
(virCommandRunAsync): Improve documentation.
* src/util/command.h (virPidWait, virPidAbort): New prototypes.
* src/libvirt_private.syms: Export them.
* docs/internals/command.html.in: Document them.
Guarantee that outbuf/errbuf are allocated on success, even if to the
empty string. Caller always has to free the result, and empty output
check requires checking if *outbuf=='\0'. Makes the API easier to use
safely. Failure is best effort allocation (some paths, like
out-of-memory, cannot allocate a buffer, but most do), so caller must
free buffer on failure.
* docs/internals/command.html.in: Update documentation.
* src/util/command.c (virCommandSetOutputBuffer)
(virCommandSetErrorBuffer, virCommandProcessIO) Guarantee empty
string on no output.
* tests/commandtest.c (test17): New test.
* docs/internals/command.html.in: Better documentation of buffer
vs. fd considerations.
* src/util/command.c (virCommandRunAsync): Reject raw execution
with string io.
(virCommandRun): Reject execution with user-specified fds not
visiting a regular file.
