Great to see someone working on it. What sorts of roadblocks came out of reflection? How does the wrapper design solve the pluggability issue? This is pretty important to me, since I've worked with several companies now that end up subclassing LibvirtComputingResource in order to handle their own Commands on the hypervisor from their server-side plugins, and changing their 'resource' to that in agent.properties. Since the main agent class needs to be set at agent join, this is harder to manage than it should be.
I mentioned the reflection model because that's how I tend to handle the commands when subclassing LibvirtComputingResource. I haven't had any problems with it, but then again I haven't tried to refactor 5500 lines into that model, either. On Thu, Apr 23, 2015 at 1:17 AM, Wilder Rodrigues <wrodrig...@schubergphilis.com> wrote: > Hi Marcus, > > I like the annotation idea, but reflection is trick because it hides some > information about the code. > > Please, have a look at the CitrixResourceBase after the refactor I did. It > became quite smaller and test coverage was improved. > > URL: > https://cwiki.apache.org/confluence/display/CLOUDSTACK/Refactoring+XenServer+Hypervisor+Plugin > > The same patter is being about to Libvirt stuff. The coverage on the KVM > hypervisor plugin already went from 4 to 10.5% after refactoring 6 commands > > Cheers, > Wilder > > On 22 Apr 2015, at 23:06, Marcus <shadow...@gmail.com> wrote: > > Kind of a tangent, but I'd actually like to see some work done to > clean up LibvirtComputing resource. One model I've prototyped that > seems to work is to create an annotation, such as > 'KVMCommandExecutor', with a 'handles' property. With this annotation, > you implement a class that handles, e.g. StartCommand, etc. Then in > LibvirtComputingResource, the 'configure' method fetches all of these > executors via reflection and stores them in an object. Then, instead > of having all of the 'instanceof' lines in LibvirtComputingResource, > the executeRequest method fetches the executor that handles the > incoming command and runs it. > > I think this would break up LibvirtComputingResource into smaller, > more testable and manageable chunks, and force things like config and > utility methods to move to a more sane location, as well. As a bonus, > this model makes things pluggable. Someone could ship KVM plugin code > containing standalone command executors that are discovered at runtime > for things they need to run at the hypervisor level. > > On Tue, Apr 21, 2015 at 6:27 AM, Wilder Rodrigues > <wrodrig...@schubergphilis.com> wrote: > > Hi all, > > Yesterday I started working on the LibvirtComputingResource class in order > to apply the same patterns I used in the CitrixResourceBase + add more unit > tests to it After 10 hours of work I got a bit stuck with the 1st test, > which would cover the refactored LibvirtStopCommandWrapper. Why did I get > stuck? The class used a few static methods that call native libraries, which > I would like to mock. However, when writing the tests I faced problems with > the current Mockito/PowerMock we are using: they are simply not enough for > the task. > > What did I do then? I added a dependency to EasyMock and PowerMock-EasyMock > API. It worked almost fine, but I had to add a “-noverify” to both my > Eclipse Runtime configuration and also to the > cloud-plugin-hypervisor-kvm/pom.xml file. I agree that’s not nice, but was > my first attempt of getting it to work. After trying to first full build I > faced more problems related to ClassDefNotFoundExpcetion which were > complaining about Mockito classes. I then found out that adding the > PowerMockRunner to all the tests classes was going to be a heavy burden and > would also mess up future changes (e.g. the -noverify flag was removed from > Java 8, thus adding it now would be a problem soon). > > Now that the first 2 paragraphs explain a bit about the problem, let’s get > to the solution: Java 8 > > The VerifyError that I was getting was due to the use of the latest EasyMock > release (3.3.1). I tried to downgrade it to 3.1/3.2 but it also did not > work. My decision: do not refactor if the proper tests cannot be added. This > left me with one action: migrate to Java 8. > > There were mentions about Java 8 in february[1] and now I will put some > energy in making it happen. > > What is your opinion on it? > > Thanks in advance. > > Cheers, > Wilder > > http://mail-archives.apache.org/mod_mbox/cloudstack-dev/201502.mbox/%3c54eef6be.5040...@shapeblue.com%3E<http://mail-archives.apache.org/mod_mbox/cloudstack-dev/201502.mbox/<54eef6be.5040...@shapeblue.com>> > >
