[libvirt] [PATCH 0/5] Testing libvirt XML -> libxl_domain_config conversion

At the Xen Hackathon I learnt that libxl provides an API which can serialize a libxl_domain_config instance to a JSON document. This is exactly what we need for testing the XML -> libxl_domain_config conversion process, so I spent the afternoon trying to get such a test working. The result is that we can now just add pairs of XML, JSON files to libvirt to test handling of new config features. I hit a couple of small issues with libxl, which I worked around, when writing this test which I why I'm copying xen-devel - libxl_ctx_alloc() will call xs_daemon_open and xc_interface_open, and stat /var/run/xenstored.pid to see if Xen is actually running. This fails when run on non-Xen hosts (and also possibly if run unprivileged). I used an evil LD_PRELOAD hack to stub out xs_daemon_open and xc_interface_open to return (void*)0x1, and also turn xc_interface_close and xs_daemon_close to no-ops, and make stat() always return success for xenstored.pid. This works (evidenced by the fact that if something was needing these xs/xc handles they would have crashed referencing 0x1), but at the same time it might be an idea to have an officially supported "non live" mode for libxl_ctx_alloc() turned on by a flag of some sort. - The libxl_json.h header file is relying on conditionals that are only set by Xen's build process eg HAVE_YAJL_YAJL_VERSION_H I hacked around this, but it is a little dirty too. libvirt already links to libyajl for the QEMU driver, but we don't really need the raw YAJL objects. It'd be nice to have a char * libxl_domain_config_as_json(libxl_domain_config *p) as a higher level wrapper around libxl_domain_config_gen_json avoiding the pain of dealing with YAJL's different APIs. Ian J mentioned to me that he thought there was already such a method, but AFAICT, the only such code is in the 'xl' command line tool itself (xl_cmdimpl.c - printf_info_one_json) A few further ideas that could be done as a followup - Make virConnectDomainXMLToNative accept 'xl-json" as a data format, so you can feed in a libvirt XML and get back out a JSON document. This could be a useful debugging tool for Xen developers trying to identify bugs in libvirt. - Write out the JSON document to /var/log/libvirt/libxl/$GUEST.log whenever starting a guest. Again this would be a useful debugging aid to Xen developers / support people trying to identify why a guest might be mis-behaving Regards, Daniel Daniel P. Berrange (5): Don't pass virDomainObjPtr to libxlBuildDomainConfig Don't pass libxlDriverPrivatePtr into libxlBuildDomainConfig libxl: Move virDomainXMLOptionNew into libxlCreateXMLConf Add more test suite mock helpers Add a test suite for libxl option generator src/libxl/libxl_conf.c | 38 +++--- src/libxl/libxl_conf.h | 10 +- src/libxl/libxl_domain.c | 7 +- src/libxl/libxl_driver.c | 4 +- tests/Makefile.am | 25 +++- tests/libxlxml2jsondata/minimal.json | 172 +++++++++++++++++++++++++++ tests/libxlxml2jsondata/minimal.xml | 36 ++++++ tests/libxlxml2jsontest.c | 219 +++++++++++++++++++++++++++++++++++ tests/virfirewalltest.c | 4 +- tests/virmock.h | 54 ++++++--- tests/virmocklibxl.c | 87 ++++++++++++++ tests/virsystemdtest.c | 4 +- 12 files changed, 617 insertions(+), 43 deletions(-) create mode 100644 tests/libxlxml2jsondata/minimal.json create mode 100644 tests/libxlxml2jsondata/minimal.xml create mode 100644 tests/libxlxml2jsontest.c create mode 100644 tests/virmocklibxl.c -- 1.9.3