Skip to main content

Qemu VM management utilities

Project description

=============================================
Flying Circus QEMU virtual machine management
=============================================

This package provides a utility to manage virtual machines and their life cycle
in the Flying Circus. We try to keep specifics of our environment out of there,
but we make a few assumptions:

* VM disks (root, swap, tmp) are stored in Ceph
* There is a script `create-vm` that will prepare a fresh root disk image.

The utility allows you to

* start, stop and migrate VMs between hosts
* run a daemon that enforces the policy about running VMs
given by a set of config files
* resize disks.


Config format
=============

Generic template
----------------

The Qemu config file will be generated from a template. If no template is found
in `/etc/qemu/qemu.vm.cfg.in`, a built-in default template will be used. Refer
to qemu.vm.cfg.in in the source distribution.


Per-VM configuration
--------------------

Expects a config file for each VM in `/etc/qemu/vm/*.cfg`.

The config file format is YAML.

Format::

name: test00
parameters:
id: 12345
resource_group: test

online: true
kvm_host: bob

disk: 5
memory: 512
cores: 1

nics:
- srv: 00-01-02-03-05-06
- fe: 00-01-02-03-05-06


.. vim: set ft=rst:

Release notes
=============


0.8.5 (2016-10-31)
------------------

- Fixed a major bug with event processing: the consul event processor was
using the multiprocessing.pool API incorrectly. This wasn't caught by the
tests and resulted in silent "no ops" of all event processing mechanisms.


0.8.4 (2016-10-31)
------------------

- Waiting for Qemu to shutdown gracefully was not expecting a socket error,
which caused restarts to fail (cleanly). #24434

- Limit the number of parallel processed consul events to avoid
overloading the host. Can be configured in the fc-qemu config file through::

[consul]
event-threads = <INT>

The default is 10 threads.

- Lower the overhead of processing a consul config change event: do not
activate Ceph and Qemu connections and do not perform scrubbing (ensure)
when the config hasn't changed. Ceph and Qemu connections aren't needed in
that case and scrubbing is expected to be performed in a separate task from
a scheduler, not from an event handler that is supposed to only respond to
changes.

- Provide a default for the binary-generation counter to allow smooth
upgrades from previous versions.


0.8.3 (2016-10-23)
------------------

- Lower the guest agent timeout to help the tests complete faster and also
stay responsive if the guest shouldn't have an agent available either
yet, or currently, or generally.

- Provide a Qemu config template variable that will determine the most current
Qemu machine type, given a prefix to filter for.

- Provide a "binary generation counter" that is a) injected a boot
(to /tmp/fc-data/qemu-binary-generation-booted) and b) updated during every
"ensure" command (to /run/qemu-binary-generation-current). The guest should
use a difference between those files to schedule a cold reboot (i.e. a
shutdown) to restart with a fresh Qemu binary.


0.8.2 (2016-09-20)
------------------

- Switch from using multiprocessing to threaded management of multiple consul
VM event handlers to reduce Python startup overhead when processing many VMs
in a single location. Also remove the sleep time.

- Fix log error in consul snapshot event handling. Improve the test coverage
for consul event handling.

- Remove superfluous VM name handling where a VM config file could be
specified instead of a VM name. This was causing obfuscation in the code
and was barely used anyway.

- Allow using the telnet command even when fc.qemu _thinks_ that the VM
is not running. This command is helpful for debugging and blocking it
is a useless seatbelt.

- Do not log QMP connection errors as the are extremely common and expected.


0.8.1 (2016-09-11)
------------------

- Explicitly add logging to /var/log/fc-qemu.log. Do not filter
log output there: we always want all the information we can get.

0.8 (2016-09-08)
----------------

- Introduce `fc-qemu telnet` command: a shortcut to connect to the human
monitor port without having to look up the port from a config manually.

- Switch the monitor automation from using the telnet port to using the QMP
socket. This should be a _lot_ more reliable. This also fixes a previous
race condition where a migration status check may intermittently fail and
then break a migration unnecessarily.

- Update vagrant environment to check against Qemu 2.6.

- Revamp output formatting to use Hynek's great structlog library.

- Limit a few more commands to specific VM states: stop only when running.

- Implement IOPS limiting either based on VM-specific ENC data,
a Ceph pool default, or a global default. This limits IOPS for all disks
(individually, no groups, yet) in a VM and maintains this over time.

- Rework Ceph volume unlocking: if a client owns a lock then breaking it
will cause an immediate disconnect of the rbd/rados connection to avoid
it sending further data updates. This can happen to us if we're setting
up the locks on an inmigration and then have to give them up again if the
migration fails.

0.7.22 (2016-07-21)
-------------------

- Fix bug in `fc-qemu restart` which causes mkfs.xfs for tmp to fail.


0.7.21 (2016-06-20)
-------------------

- Moderate swap and tmp volume sizes so that they do not scale linearly for very
large VMs. #21961


0.7.20 (2016-05-03)
-------------------

- More logging output to help diagnosing a rare lock recovery failure
(#21345).
- Remove shrink-vm. R.I.P. (#14222).


0.7.19 (2016-04-08)
-------------------

- Fix a race condition: when continuously polling monitor status to determine
whether a VM is running, also consider the option that the VM was about
to shutdown and the monitor has gone away.


0.7.18 (2016-04-04)
-------------------

- Another brownbag release: the snapshot refactoring wasn't tested properly
if snapshots actually existed.


0.7.17 (2016-04-04)
-------------------

- Fix unicode/str issue: consul json decoded into unicode but librbd requires
a plain string.

0.7.16 (2016-03-31)
-------------------

- Fix regression in snapshot taking.


0.7.15 (2016-03-20)
-------------------

- Account for different mkfs options for XFS and mkfs.ext4 (#19079).
- Improved Vagrant VM bootstrapping.
- Refactor classes in hazmat/{ceph.py,volume.py} (#19079).
- Use the "rbd_pool" ENC option to allow VM-specific selection of the RBD pool
instead of deriving it from the resource group name.
- Improve success rate of recovering from failed migrations properly: certain
conditions would result in only partially released locks from the target
leading to inconsistent states.

0.7.14 (2016-01-21)
-------------------

- Use XFS for tmp partitions (#17873).
- Drop super-floppy setup von vdc and use a proper partition table instead
(#17873).
- Fix file permissions for ENC seed JSON file.


0.7.13 (2015-12-10)
-------------------

- Ignore consul requests for VMs with missing configuration (#18841).
- Speed up initial NTP sync in Vagrant to avoid failing Ceph tests due to
unsynced MONs.
- Refine Ceph.unlock() to remove own locks in a best-effort manner. This is
needed to recover from incomplete migrations (#18771).
- Improve error handling with failed monitor connections.


0.7.12 (2015-11-11)
-------------------

- Improve error handling during migration.
- Fix timeout during fsfreeze that leads to locked up VMs (#18917).


0.7.11 (2015-11-04)
-------------------

- Switch `aio` setting in default qemu.vm.cfg to "threads". This will keep
fc-qemu compatible with future Qemu versions (#18743).
- Improve logging.
- Place initial copy of ENC data in `/tmp/fc-data/enc.json`.


0.7.10 (2015-08-12)
-------------------

- Refactor system-wide configuration code.
- Create swap and tmp partition with proper filesystem labels (#16783).
- Fix rare race condition during tmp volume creation.
- Set filesystem labels for swap and tmp volumes (#17078).


0.7.9 (2015-08-03)
------------------

- Add "snapshot" command. Can be triggered from command line and
via consul.


0.7.8 (2015-07-27)
------------------

- Improve detection of running instances.

- Broaden check for monitor connection to handle dual stack
environments.


0.7.7 (2015-07-14)
------------------

- Fix migration issue: we ended up de-registering at the wrong time.


0.7.6 (2015-07-01)
------------------

- Quickfix: newer mkfs.ext4 versions need a '-F' flag to overwrite
filesystems (#14920).


0.7.5 (2015-07-01)
------------------

- Spawn individual VM actions usings multiprocessing. Wait until all migrations
are done (#14920).
- Increase allowed migration downtime to keep migration time for busy VMs in
bounds (#14920).
- Fix exception handling errors during Consul event processing (#14920).
- Give udev mapping a bit to settle.
- Improve log readability.


0.7.4 (2015-06-02)
------------------

- Rectify brown-bag release.
- Fix some unnoticed, arbitrary test failures.


0.7.3 (2015-06-02)
------------------

- Make event processing from consul fork for each VM and return the
master process early to avoid blocking the consul agent.

- More logging related to migrations.


0.7.2 (2015-05-26)
------------------

- Adapt to QEMU 2.2.1: uses now stdvga by default (#15748).


0.7.1 (2015-05-20)
------------------

- Fix bug with inmigration Consul service registration (#15313).
- Change KV name name space for nodes from "vm/" to "node/" (#14920).


0.7 (2015-05-18)
----------------

- Consul service registration (#15313).
- Coordinate migration via Consul (#15313).


0.6.4 (2015-02-27)
------------------

- Tolerate "setup" as an intermediate migration status as encountered in the
wild.


0.6.3 (2015-02-19)
------------------

- Improve pid file parser to deal correctly with trailing lines and empty pid
files.
- Ensure that exceptions are properly logged if they occur directly after
daemonizing (e.g., in Agent.__init__()) (#13867).


0.6.2 (2015-01-22)
------------------

- Relax PyYaml and psutil version requirements to accommodate to the Flying
Circus managed platform.


0.6.1 (2015-01-22)
------------------

- Improve logging and error messages (#13867).
- Fix unwanted behaviour during error conditions (#13867).


0.6 (2015-01-15)
----------------

- Implement live migration. Use "inmigrate" and "outmigrate" commands
to coordinate the process (#13229).
- Note that the qemu.cfg.in template has changed!
- Improve test coverage.


0.5.1 (2014-11-22)
------------------

- Bugfix: remove Ceph discard call since it seems to be unstable (#13414).
- Improve operability by reworking what is logged to fc-qemu.log.


0.5 (2014-11-21)
----------------

- Root filesystem shrink during VM start (#13414).
- Add 'force-unlock' action to break stale locks (e.g., after a VM host went
down).


0.4.3 (2014-11-13)
------------------

- Read Qemu config file template from `/etc/qemu/qemu.vm.cfg.in`.
- Fix tests and documentation.


0.4.2 (2014-11-12)
------------------

- Rate limit entropy transfer from host to guest (#13751).
- Add 'restart' command to simplify VM restarts.


0.4.1 (2014-09-24)
------------------

- Do not require the PID to match the machine name for determining
online status. This caused issues for VMs with names longer than 11
characters: http://status.flyingcircus.io/incidents/3j8wsrszlx2w


0.4 (2014-09-16)
----------------

- Allow selecting the specific command line to call for creating a VM
using a config file + formatting syntax.

- Add test coverage to show that we gracefully recover from crashed VMs
upon a subsequent 'ensure'.

0.3 (2014-09-13)
----------------

- Refactor and rename to 'fc.qemu'.
Integrate most functionality that was previously placed in our
init scripts and localconfig (fc.agent) utilities.

- Add a lot of test coverage.


0.2.6 (2014-08-21)
------------------

- Fix incoming VM detection for an already locked _and_ started VM.


0.2.5 (2014-08-20)
------------------

* Implement a safety-belt to prohibit migrating VMs that have not
yet been started with the supported /run/kvm.*.cfg.in format.


fc.qemu development
===================

Workstation development
-----------------------

Prepare Vagrant environment::

host$ hg clone https://bitbucket.org/flyingcircus/fc.qemu
host$ cd fc.qemu
host$ vagrant up
host$ vagrant ssh

Prepare virtualenv::

vm$ cd /vagrant
vm$ virtualenv --system-site-packages .
vm$ bin/pip install -r requirements.txt

Run the tests::

vm$ cd /vagrant
vm$ sudo bin/py.test

Test execution automatically updates a coverage report in the `htmlcov`
directory.

Run end-to-end migration test::

vm$ cd /vagrant
vm$ sudo ./test-migration.sh


Real-world testing on FCIO DEV network
--------------------------------------

* Check out the source on a VM host
* Set Puppet stopper
* Create virtualenv: `virtualenv --system-site-packages .`
* Install software: `bin/pip install -r requirements.txt`
* Make symlink /usr/src/fc.qemu point to the local checkout
* Install fc-qemu package in development mode:
`ACCEPT_KEYWORDS="**" emerge -1 fc-qemu`

.. vim: set ft=rst:

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

fc.qemu-0.8.5.tar.gz (49.2 kB view hashes)

Uploaded Source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page