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This defines a new RPC protocol to be used between the LXC controller and the libvirtd LXC driver. There is only a single RPC message defined thus far, an asynchronous "EXIT" event that is emitted just before the LXC controller process exits. This provides the LXC driver with details about how the container shutdown - normally, or abnormally (crashed), thus allowing the driver to emit better libvirt events. Emitting the event in the LXC controller requires a few little tricks with the RPC service. Simply calling the virNetServiceClientSendMessage does not work, since this merely queues the message for asynchronous processing. In addition the main event loop is no longer running at the point the event is emitted, so no I/O is processed. Thus after invoking virNetServiceClientSendMessage it is necessary to mark the client as being in "delayed close" mode. Then the event loop is run again, until the client completes its close - this happens only after the queued message has been fully transmitted. The final complexity is that it is not safe to run virNetServerQuit() from the client close callback, since that is invoked from a context where the server is locked. Thus a zero-second timer is used to trigger shutdown of the event loop, causing the controller to finally exit. * src/Makefile.am: Add rules for generating RPC protocol files and dispatch methods * src/lxc/lxc_controller.c: Emit an RPC event immediately before exiting * src/lxc/lxc_domain.h: Record the shutdown reason given by the controller * src/lxc/lxc_monitor.c, src/lxc/lxc_monitor.h: Register RPC program and event handler. Add callback to let driver receive EXIT event. * src/lxc/lxc_process.c: Use monitor exit event to decide what kind of domain event to emit * src/lxc/lxc_protocol.x: Define wire protocol for LXC controller monitor. Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
libvirt library code README
===========================
The directory provides the bulk of the libvirt codebase. Everything
except for the libvirtd daemon and client tools. The build uses a
large number of libtool convenience libraries - one for each child
directory, and then links them together for the final libvirt.so,
although some bits get linked directly to libvirtd daemon instead.
The files directly in this directory are supporting the public API
entry points & data structures.
There are two core shared modules to be aware of:
* util/ - a collection of shared APIs that can be used by any
code. This directory is always in the include path
for all things built
* conf/ - APIs for parsing / manipulating all the official XML
files used by the public API. This directory is only
in the include path for driver implementation modules
* vmx/ - VMware VMX config handling (used by esx/ and vmware/)
Then there are the hypervisor implementations:
* esx/ - VMware ESX and GSX support using vSphere API over SOAP
* hyperv/ - Microsoft Hyper-V support using WinRM
* lxc/ - Linux Native Containers
* openvz/ - OpenVZ containers using cli tools
* phyp/ - IBM Power Hypervisor using CLI tools over SSH
* qemu/ - QEMU / KVM using qemu CLI/monitor
* remote/ - Generic libvirt native RPC client
* test/ - A "mock" driver for testing
* uml/ - User Mode Linux
* vbox/ - Virtual Box using native API
* vmware/ - VMware Workstation and Player using the vmrun tool
* xen/ - Xen using hypercalls, XenD SEXPR & XenStore
* xenapi/ - Xen using libxenserver
Finally some secondary drivers that are shared for several HVs.
Currently these are used by LXC, OpenVZ, QEMU, UML and Xen drivers.
The ESX, Hyper-V, Power Hypervisor, Remote, Test & VirtualBox drivers all
implement the secondary drivers directly
* cpu/ - CPU feature management
* interface/ - Host network interface management
* network/ - Virtual NAT networking
* nwfilter/ - Network traffic filtering rules
* node_device/ - Host device enumeration
* secret/ - Secret management
* security/ - Mandatory access control drivers
* storage/ - Storage management drivers
Since both the hypervisor and secondary drivers can be built as
dlopen()able modules, it is *FORBIDDEN* to have build dependencies
between these directories. Drivers are only allowed to depend on
the public API, and the internal APIs in the util/ and conf/
directories