virt-test: Add sphinx documentation

After some work with the virt-test wiki, it has been
converted to the sphinx format. Although many of the
rough edges and outdated docs were put into shape,
there's still a lot to be done. It's good to have
it out there and integrated early, where we can
work on it.

Signed-off-by: Lucas Meneghel Rodrigues <[email protected]>

documentation/Makefile

@@ -0,0 +1,153 @@
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
+PAPER         =
+BUILDDIR      = build
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) source
+# the i18n builder cannot share the environment and doctrees with the others
+I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) source
+
+.PHONY: help clean html dirhtml singlehtml pickle json htmlhelp qthelp devhelp epub latex latexpdf text man changes linkcheck doctest gettext
+
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  html       to make standalone HTML files"
+	@echo "  dirhtml    to make HTML files named index.html in directories"
+	@echo "  singlehtml to make a single large HTML file"
+	@echo "  pickle     to make pickle files"
+	@echo "  json       to make JSON files"
+	@echo "  htmlhelp   to make HTML files and a HTML help project"
+	@echo "  qthelp     to make HTML files and a qthelp project"
+	@echo "  devhelp    to make HTML files and a Devhelp project"
+	@echo "  epub       to make an epub"
+	@echo "  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
+	@echo "  latexpdf   to make LaTeX files and run them through pdflatex"
+	@echo "  text       to make text files"
+	@echo "  man        to make manual pages"
+	@echo "  texinfo    to make Texinfo files"
+	@echo "  info       to make Texinfo files and run them through makeinfo"
+	@echo "  gettext    to make PO message catalogs"
+	@echo "  changes    to make an overview of all changed/added/deprecated items"
+	@echo "  linkcheck  to check all external links for integrity"
+	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
+
+clean:
+	-rm -rf $(BUILDDIR)/*
+
+html:
+	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
+
+dirhtml:
+	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
+
+singlehtml:
+	$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
+	@echo
+	@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."
+
+pickle:
+	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
+	@echo
+	@echo "Build finished; now you can process the pickle files."
+
+json:
+	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
+	@echo
+	@echo "Build finished; now you can process the JSON files."
+
+htmlhelp:
+	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
+	@echo
+	@echo "Build finished; now you can run HTML Help Workshop with the" \
+	      ".hhp project file in $(BUILDDIR)/htmlhelp."
+
+qthelp:
+	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
+	@echo
+	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
+	      ".qhcp project file in $(BUILDDIR)/qthelp, like this:"
+	@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/VirtTest.qhcp"
+	@echo "To view the help file:"
+	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/VirtTest.qhc"
+
+devhelp:
+	$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
+	@echo
+	@echo "Build finished."
+	@echo "To view the help file:"
+	@echo "# mkdir -p $$HOME/.local/share/devhelp/VirtTest"
+	@echo "# ln -s $(BUILDDIR)/devhelp $$HOME/.local/share/devhelp/VirtTest"
+	@echo "# devhelp"
+
+epub:
+	$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
+	@echo
+	@echo "Build finished. The epub file is in $(BUILDDIR)/epub."
+
+latex:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo
+	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
+	@echo "Run \`make' in that directory to run these through (pdf)latex" \
+	      "(use \`make latexpdf' here to do that automatically)."
+
+latexpdf:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through pdflatex..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+text:
+	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
+	@echo
+	@echo "Build finished. The text files are in $(BUILDDIR)/text."
+
+man:
+	$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
+	@echo
+	@echo "Build finished. The manual pages are in $(BUILDDIR)/man."
+
+texinfo:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo
+	@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
+	@echo "Run \`make' in that directory to run these through makeinfo" \
+	      "(use \`make info' here to do that automatically)."
+
+info:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo "Running Texinfo files through makeinfo..."
+	make -C $(BUILDDIR)/texinfo info
+	@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."
+
+gettext:
+	$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
+	@echo
+	@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."
+
+changes:
+	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
+	@echo
+	@echo "The overview file is in $(BUILDDIR)/changes."
+
+linkcheck:
+	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
+	@echo
+	@echo "Link check complete; look for any errors in the above output " \
+	      "or in $(BUILDDIR)/linkcheck/output.txt."
+
+doctest:
+	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
+	@echo "Testing of doctests in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/doctest/output.txt."

documentation/source/advanced/MultiHostMigration.rst

@@ -0,0 +1,165 @@
+Writing your own QEMU multi host migration test
+==============================================
+
+Client part of Autotest works only on a single host, for this reason multi host
+migration test needs to be started from the server part of Autotest. The server
+module is responsible for preparing all hosts, then to start client part with
+the appropriate parameters. To simplify writing a multi host migration, we
+developed the MultihostMigration class. The class is a framework class that
+allows to create, start and sync migration scenario over multiple host, taking
+care of most of the heavy lifting for you.
+
+Prepare env
+-----------
+
+For migration without disk migration is necessary have shared storage (NFS, ceph, etc.).
+There have to be placed images of guests system in shared storage.
+Nested virtualization config 
+:doc:`Use nested virt to develop multi host tests <../advanced/VirtualEnvMultihost>`
+
+Prepare config files
+--------------------
+
+Multi host migration uses almost all the configuration files from standard virt
+tests. The only difference the main configuration file, named
+``multi-host-tests.cfg``. All multi host migration tests are defined in
+``client/virt/qemu/tests/cfg/multi-host.cfg``.
+
+Start multi host migration tests
+--------------------------------
+
+The server part of Autotest, just as the client part, uses a control file to
+describe the operations to be executed on a test job. The multi host migration
+control file can be found at ``client/virt/qemu/multi_host.srv``.
+
+Starting autoserv:
+
+Change your current working directory to the root of the autotest repo, say
+``/home/myuser/Code/autotest``:
+
+::
+
+    cd /home/myuser/Code/autotest
+    server/autoserv -m 192.168.100.220,192.168.100.240 client/tests/virt/qemu/multi_host.srv
+
+the command starts autotest on machine 192.168.100.220 and 192.168.100.240 and
+uses them for multi_host.srv control file. If four machines are defined it'll
+create two pairs and with each pair the independent migration test is started.
+Because of it there is added new arg "all" in multi_host.srv. It starts
+one migration test with all machines.
+
+::
+
+    server/autoserv -m 192.168.100.220,192.168.100.240,192.168.100.221 -a all client/virt/qemu/multi_host.srv
+
+
+.. _multihost_migration:
+
+Using of MultihostMigration class
+---------------------------------
+
+Scheme:
+~~~~~~~
+
+.. figure:: MultiHostMigration/multihost-migration.png
+
+:download:`Source file for the diagram above (LibreOffice file) <MultiHostMigration/multihost-migration.odg>`
+
+
+Example:
+~~~~~~~~
+
+::
+
+    class TestMultihostMigration(virt_utils.MultihostMigration):
+        def __init__(self, test, params, env):
+            super(testMultihostMigration, self).__init__(test, params, env)
+
+        def migration_scenario(self):
+            srchost = self.params.get("hosts")[0]
+            dsthost = self.params.get("hosts")[1]
+
+            def worker(mig_data):
+                vm = env.get_vm("vm1")
+                session = vm.wait_for_login(timeout=self.login_timeout)
+                session.sendline("nohup dd if=/dev/zero of=/dev/null &")
+                session.cmd("killall -0 dd")
+
+            def check_worker(mig_data):
+                vm = env.get_vm("vm1")
+                session = vm.wait_for_login(timeout=self.login_timeout)
+                session.cmd("killall -9 dd")
+
+            # Almost synchronized migration, waiting to end it.
+            # Work is started only on first VM.
+
+            self.migrate_wait(["vm1", "vm2"], srchost, dsthost,
+                              worker, check_worker)
+
+            # Migration started in different threads.
+            # It allows to start multiple migrations simultaneously.
+
+            # Starts one migration without synchronization with work.
+            mig1 = self.migrate(["vm1"], srchost, dsthost,
+                                worker, check_worker)
+
+            time.sleep(20)
+
+            # Starts another test simultaneously.
+            mig2 = self.migrate(["vm2"], srchost, dsthost)
+            # Wait for mig2 finish.
+            mig2.join()
+            mig1.join()
+
+    mig = TestMultihostMigration(test, params, env)
+    # Start test.
+    mig.run()
+
+When you call:
+
+::
+
+    mig = TestMultihostMigration(test, params, env):
+
+What happens is
+
+1. VM's disks will be prepared.
+2. The synchronization server will be started.
+3. All hosts will be synchronized after VM create disks.
+
+When you call the method:
+
+::
+
+    migrate():
+
+What happens in a diagram is:
+
++------------------------------------------+-----------------------------------+
+|                source                    |             destination           |
++==========================================+===================================+
+|                  It prepare VM if machine is not started.                    |
++------------------------------------------+-----------------------------------+
+|            Start work on VM.             |                                   |
++------------------------------------------+-----------------------------------+
+|          ``mig.migrate_vms_src()``       |   ``mig.migrate_vms_dest()``      |
++------------------------------------------+-----------------------------------+
+|                                          | Check work on VM after migration. |
++------------------------------------------+-----------------------------------+
+|                       Wait for finish migration on all hosts.                |
++------------------------------------------+-----------------------------------+
+
+It's important to note that the migrations are made using the ``tcp`` protocol,
+since the others don't support multi host migration.
+
+::
+
+    def migrate_vms_src(self, mig_data):
+        vm = mig_data.vms[0]
+        logging.info("Start migrating now...")
+        vm.migrate(mig_data.dst, mig_data.vm_ports)
+
+
+This example migrates only the first machine defined in migration. Better example
+is in ``virt_utils.MultihostMigration.migrate_vms_src``. This function migrates
+all machines defined for migration.