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How to use SonarQube Maven plugins without running a(n explicit) server?

I'm getting started with SonarQube usage for JSF page static analysis[1] in Maven. I'm only really interested in using it in Maven since I don't like the idea to introduce another build command.
After going through Analyzing the source code and the specific Maven guide I gained the impression that the plugin can only be used after downloading, installing/unpacking and starting a SonarQube instance at localhost and specifying the connection information in the plugin declaration in the POM. The plugin configuration parameter confirm that.
While this workflow might have advantages it is painful to use on CI services and the necessity to start a service manually in order to be able to build seems not very user friedly (given the fact that other development tools like Selenium or Arquillian pull entire browser, driver and servers in the background without one single line of configuration). Am I missing something about a separate plugin or configuration which manages an embedded or otherwise temporary instance to perform the analysis with a single plugin declaration?
[1] I'm aware that there're other tools based on XML validation which could do the job, but setting up a much more powerful tools like SonarQube seems to be a more flexible approach which will probably pay off.

You don't have to install SonarQube on your build server, but it is necessary to execute analysis (results will be pushed to it). It means that you have a working server somewhere and next you have to set required parameters:
sonar.host.url (http://localhost:9000 is a default value)
sonar.login and sonar.password (if your SonarQube server is secured)
See all Analysis Parameters.

Dropwizard hot deployment

I'm looking for a simple to use system in Java which creates a REST service for me. So I found dropwizard but as far as I can use google it turns out it lacks hot deployment although jetty is able to do so. When using the maven-shade-plugin it takes at least 10 seconds to build the thing. Also my IDE reports that it cannot use compile on save feature (aka hot deployment) when the shade-plugin is involved.
Can I use hotdeployment somehow? Or what can I use instead?
Update: If nothing will fix this I'll probably use a combination of jersey&guice etc which is explained in this post

You don't have to use the shade plugin to run your service. You could just compile as a regular jar file and I think that would let you use your IDEs hot deployment features.

Have you ever tried JRebel ? They have JAX-RS support as well...

Not an answer, but I wrote up an article detailing how to use git to push a Dropwizard project to your server and for it to initiate a hot replacement. It relies on git hooks and running Maven via a script on the server.
You can find the details about it here: http://gary-rowe.com/agilestack/2013/02/14/how-to-deploy-dynamic-sites-with-git/

Efficient OSGi development workflow

I work on a product composed of many bundles running as features on top of karaf. Typically our developers work on one bundle at a time. Our normal development goes something like: code, compile, copy bundle to deploy folder, test. We've also found that hotdeploy just refuses to override certain bundles that are installed as features without a server restart or a feature uninstall/reinstall, so sometimes the cycle is longer.
My question is: does anyone in the community have a better way? The way we do things works, but I feel like it's pretty slow and inefficient and I'm betting someone has come up with something better!
EDIT: I realize that I was pretty unclear in my question... We are using Equinox underneath Karaf. We also use Eclipse and Maven, although I don't know that using Maven is relevant.

Sounds like you want the dev:watch command. From the documentation:
The watch command can be used to help at developement time. It allows you to configure a set of URLs that will be monitored. All bundles location matching the given URL will be
automatically updated. This avoids the need for manually updating the bundles or even copying the bundle to the system folder if needed. Note that only maven based urls and maven snapshots will actually be updated automatically, so if you run
dev:watch *
It will actually monitor all bundles that have a location matching mvn:* that have '-SNAPSHOT' in their url.
Doing "dev:watch --help" from the Karaf shell will list its available flags and args.
Something similar is the PAX plugin
Either of these will work quite nicely if you've got the m2 maven plugin for Eclipse.
UPDATED: In my company we strive to be as TDD as possible, therefore a lot a development is done without explicitly starting Karaf. In the normal mix of unit tests we're also using Pax Exam, which is largely fantastic even when run from within Eclipse =)
This helps ensure we're not too tided to any Karaf specifics as it runs with Equinox/Felix/Concierge (so I mock out various Karaf specifics we depend on like JAAS authentication). Along with many other cool tools/functionality, it's capable of provisioning Karaf features and using TinyBundles you can even create bundles on the fly (again useful for mocking/stubbing).
Pax Exam hooks into the JUnit framework by providing a JUnit #Runner, the latest version (2) is much faster and has DSL based API, so the tests are quite concise and readable.
Using Pax Exam gives us good test coverage and short development times. Where tests are less practical or we're hunting bugs that don't surface in tests, the dev:watch command is invaluable.
In summary; IMO you should definitely drive your developments with tests (Pax Exam will slot into your existing build nicely and once you get used to it you'll find development quicker). You can start using the dev:watch command immediately, it will certainly speed up your current situation.
UPDATE 2: In answering another question I've added a maven example Pax-Exam testing a ComponentFactory. Test Driven Development is arguably the most efficient workflow available to developers today. link to question: osgi: Using ServiceFactories? and link to sourcecode: http://dl.dropbox.com/u/2465717/net.earcam.example.servicecomponent_2011-08-16_15-52.tgz

I've had excellent results using Equinox in Eclipse - even hot code replace works properly. granted, the target platform is small and we have only on the order of approx 50 bundles of our own, but workflow goes like this:
First, we have a target platform that contains all third-party and Eclipse bundles, Eclipse takes care of downloading & managing them. Then, the workspace has all the bundles of the project, grouped in 3-4 working sets. Compilation happens as usual on save, sometimes GWT needs to be recompiled, but even then the changes get picked up immediately because no deployment needs to happen - the running Equinox system uses the unpacked project folders as bundles. Running this from within Eclipse gives us hot code replace, on-the-fly changing template files, only MANIFEST.MF/plugin.xml changes need to refresh the bundle - and even then it's usually faster to just restart the framework than to type in the console.

if you use Eclipse Eclipse Libra may be useful for you. Libra can start Felix, Equinox and Knopflerfish inside Eclipse as any other server with WST. They have some youtube videos how to use it.
I also wrote some tools that can help:
An osgi bundle that picks up OSGI services that match the filter (osgitest=junit4). With that you do not write Junit classes but you can provide pre-configured objects (e.g. with OSGI Blueprint). JUnit than runs based on the annotations provided in the interface your service implements.
A maven plugin that has the following useful goals
Start a OSGI containers and deploy the bundle maven project with all of it's dependencies (which are OSGI bundles of course). The OSGI container starting is done with the help of PAX Exam but the JUnit tests are started with the help of the OSGI bundle I wrote (that runs the OSGI services you may provide).
Create a folder that contains a shortcut to all dependencies of the project (located at the maven repo or target directory of the folder)
If the projects are deployed onto the server (Eclipse Libra) I have to say only update X where the X is the id of the bundle and everything is refreshed rapidly. You do not have to re-compile the projects that are published to the server if you run Equinox in Libra as it points to the target classes folder which is refreshed as soon as you save your class or pom.xml.
If you do not publish your project onto the server but add it as a bundle in the container pointing to the shortcut folder you can also run the update command on the OSGi console after running mvn install (without the restarting of the server).
A step-by-step guide is available at http://cookbook.everit.org/
With the following method above it is possible to write tests as TDD tests and run them as part of a maven compile on the CI server.
I hope you will find these tools as useful as I do!

It depends on the platform under Karaf: Felix or Equinox.
Equinox
Eclipse has excellent (or almost excellent) support for launching Equinox with bundles of your choice. The two things you need to prepare are:
Bundles, being developed, available in the workspace as Plug-in projects
Target platform, containing the remaining bundles of the application
Such setup will allow you to easily make changes to your bundles, even runtime and easily restarting the runtime when this is required. I see Karaf as more suitable when you are developing on remote system, where the bundles are deployed via SSH or FTP or when you are using external build tools like Maven, which have ability to automatically copy the bundle in the runtime after it is built.
If you are using Equinox, this will give some extra edge over as the runtime will execute the code directly from the workspace.
Felix
Felix doesn't seem to have such support for launching from Eclipse (although there is a work toward this, tracked in this Jira issue). You can also launch it as normal Java application, but this is far from convenient. In this case, using Maven will be much better alternative. You can still setup Eclipse to take full advantage of the PDE other features, only launching will be done externally.
Summary
In summary, you can always automate everything through Maven and Karaf will greatly help you in this regard. Eclipse will give a little edge, if you are using Equinox. You should be able to have hot-code replace regardless of the method you are using, because the hot-code replace doesn't even consider OSGi at all (except in the only case, when you reload your bundle and fresh class loader is created).

Can I use PostgreSQL in Maven build?

I am trying to create an integration test, which requires a running PostgreSQL server. Is it possible to start the server in maven build and stop it when tests are completed (in a separate process, I think)? Assuming the PostgreSQL server is not installed on the machine.

You are trying to push maven far beyond the intended envelope, so you'll be in for a fair amount of hurt before it will work.
Luckily postgresql can be downloaded as a zip archive.
As already mentioned above maven can use ant tasks to extend its reach. Ant has a large set of tasks to unzip files, and run commands. The sequence would be as follows :
unzip postgresql-xxx.zip in a well known directory --> INSTALL_DIR
create a data directory --> DATA_DIR
/bin/init-db -D
/bin/postgres -D
/bin/create_db -EUNICODE test
This should give you a running server with a test database.
Further issues : create a user, security (you likely want to connect via TCP/IP but this is disabled by default if I recall correct, this requires editing a config file before starting the database)
...
Good Luck.

I started writing a plugin for this purpose:
https://github.com/adrianboimvaser/postgresql-maven-plugin
It's in a very early stage and lacks documentation, but mostly works.
I already released version 0.1 to Maven Central.
I'm also releasing PostgreSQL binary distributions for all platforms as maven artifacts.
You can find the usage pattern in the plugin's integration tests.
Cheers!

Not to my knowledge. However, you could run a remote command that starts the server.

I think the usual scenario is to have a running integration test db, and not to shut it down/ restart it between builds.
But if you really want to you could set up your continuous integration server to start/ stop the db.

You sound like you are trying to build a full continuous integration environment. You should probably look into using a full CI tool such as Cruise Control or Bamboo.
How I've done it before is to set up a dedicated CI db that is accessible from the CI server, and then have a series of bash/python/whatever scripts run as a After Successful Build step which can then run whatever extra integration tasks you like. Pair that with something like liquibase and you could wipe out the CI db and make sure it is up to the latest schema every build.

Just to bring some fresh perspective into this matter:
You could also start the postgresql database as docker instance.
The plugin ecosystem for docker seems to be still in flux, so you might need to decide yourself which fits. Here are a few links to speed up your search:
https://github.com/fabric8io/docker-maven-plugin
http://heidloff.net/article/23.09.2015102508NHEBVR.htm
https://dzone.com/articles/build-images-and-run-docker-containers-in-maven

Extending/Inheriting Tomcat Projects

We are developing webapps with Eclipse + Tomcat plugin. We recently started a new app which will run on Facebook and StudiVZ (FB competitor in Germany). Since the functionality of the app will be 95% the same we split the code into separate Eclipse projects (app-core, app-facebook, app-vz). The -core project is source-linked into the -facebook and -vz projects in Eclipse. We are also using Hudson for CI and made ant scripts that import the code from the -core project before building. So basically we tried to inherit on a project level.
The described method has some flaws:
Versioning is complicated
The -core project does not run standalone, which makes automatic testing partly impossible
We need to modify some models where the -core projects classes depend on
Other problems that make me think this is not the best solution
Does anyone have suggestions for a better solution?

There are a wealth of build tools available for Java that address dependency management and versioning specifically. Many of these integrate with Hudson and Eclipse.
I'd suggest looking at Maven and how it does dependency management as a good starting point. Even if you don't use Maven itself, many of the solutions out there build on Maven's dependency management mechanism. Something like Apache Ivy allows you to use maven dependency management, but still use your own custom Ant scripts; whereas something like Gradle is wholesale replacement.

You should be able to split your project into 3 or more parts and then establish dependencies via Java Build Path. You need to clean up the dependencies between the projects. If you need to configure your core components depending on whether it is a -facebook or a -vz project, you might need to separate configuration, maybe even use Spring or similar dependency injection framework.
When trying to introduce reuse into web-based Java projects, usually the problems arise in the UI code. Not many frameworks were built with this approach in mind.

I don't use/hate Eclipse[1], but can point to how we deal with a similar problem.
We use Maven with IntelliJ. In particular, both of these support modules which have defined internal dependencies. In your case it could be -fb and -vz modules depending on core, or you can split core into smaller parts (such as DAO, business logic, etc.).
When compiling, deliverables of "upper" modules would be used to build "lower" modules.
Let's go over points/flaws you have raised:
versioning is no longer a problem as everything sits under the same root of Subversion/GIT/VCS of your choice
Why is that a problem? Certainly this shouldn't be an issue for unit tests as how I understand TDD, these should not require complex environments. For automated tests, you would have to test the core API (as this is the interface between core and everything else, right?) hence this shouldn't require any fronted stuff?
you need to explain your other points to tell why you don't like it
It is against Geneva convention to ask a developer to use anything other than IDE of his/her choice.