DDevelopment & Design

Meet Sputnik – static code analyser for Gerrit

Sputnik runs Checkstyle, PMD and FindBugs for your Gerrit patchsets I am happy to announce a first release of Sputnik! It is a static code analyzer that runs Checkstyle, PMD and FindBugs for your Gerrit patchsets. Its main advantage over my previous pr…

Sputnik runs Checkstyle, PMD and FindBugs for your Gerrit patchsets

I am happy to announce a first release of Sputnik! It is a static code analyzer that runs Checkstyle, PMD and FindBugs for your Gerrit patchsets. Its main advantage over my previous project Sonar Gerrit plugin is that Sputnik is a small, lightweight and standalone Java application. You don’t need any other software to run it. It bundles Checkstyle, PMD and FindBugs jars within distribution zip.

Workflow

Sputnik is intended to use with Gerrit and Continous Integration server, i. e. Jenkins. It works like this:

Your CI server is updated by ssh that a new patch is submitted to Gerrit. CI fetches this patch and builds a while project. After a build, CI server reports its result to Gerrit. It’s time for Sputnik now.

Sputnik runs regardless of build result (you can change that in your CI configuration). Sputnik fetches patchset’s file list from Gerrit over HTTP REST API. Then it runs an analysis only on these files! Even if your project is huge, analysis on several files takes only seconds. Sputnik collects comments from all three analysers: Checkstyle, PMD and FindBugs. It sends back all comments to Gerrit via HTTP REST API back. It’s very simple and very fast!

Installation and configuration

First, you need to build https://github.com/TouK/sputnik master or download distribution zip from here: sputnik-1.0.zip. Go to you CI server and extract it to a directory of your choice. Remember that a user you run CI builds needs to have an access rights to this directory (in my case it’s simply a jenkins user). Then you need to prepare your configuration file and write this file to the same directory as unzipped distribution. It is a simple Java properties file, which is pretty self-explanatory. Here is an example:

gerrit.host=gerrit.yourcompany.com
gerrit.port=8080
gerrit.username=sputnik
gerrit.password=Pa$$wo4d
checkstyle.enabled=true
checkstyle.configurationFile=/opt/jenkins/sputnik/checkstyle.xml
checkstyle.propertiesFile=
pmd.enabled=true
pmd.ruleSets=/opt/jenkins/sputnik/pmd.xml
findbugs.enabled=true
findbugs.includeFilter=/opt/jenkins/sputnik/findbugs.xml
findbugs.excludeFilter=

Now you need to configure you CI server to actually run Sputnik after a build. It is very simple for Jenkins, just add a Post-Build Step. You can adjust if Sputnik runs only on successful build or for every build – use radio buttons for this:

Last line with exit 0 is a workaround for a clean exit, even if Sputnik fails for some reason. Exit 0 guarantees you that result of this step doesn’t affect overall build result.

Summary

This is an example screenshot of Sputnik’s comments:

Sputnik always reports +1 as a result. It can be lacking in some network and authorisation configuration. But it’s open source so please submit issues and patches to its github page: https://github.com/TouK/sputnik.

Your feedback and pull requests are heartly welcome!

— Previous article

TouK with the 33rd Degree Conference

Next article —

Spring Boot and AngularJS quick start

You May Also Like
DDevelopment & Design

Log4j and MDC in Grails

Log4j provides very useful feature: MDC - mapped diagnostic context. It can be used to store data in context of current thread. It may sound scary a bit but idea is simple.

My post is based on post http://burtbeckwith.com/blog/?p=521 from Burt Beckwith's excellent blog, it's definitely worth checking if you are interested in Grails.

Short background story...


Suppose we want to do logging our brand new shopping system and we want to have in each log customer's shopping basket number. And our system can be used at once by many users who can perform many transactions, actions like adding items and so on. How can we achieve that? Of course we can add basket number in every place where we do some logging but this task would be boring and error-prone. 

Instead of this we can use MDC to store variable with basket number in map. 

In fact MDC can be treated as map of custom values for current thread that can be used by logger. 


How to do that with Grails?


Using MDC with Grails is quite simple. All we need to do is to create our own custom filter which works for given urls and puts our data in MDC.

Filters in Grails are classes in directory grails-app/conf/* which names end with *Filters.groovy postfix. We can create this class manually or use Grails command: 
grails create-filters info.rnowak.App.Basket

In result class named BasketFilters will be created in grails-app/conf/info/rnowak/UberApp.

Initially filter class looks a little bit empty:
class BasketFilters {
    def filters = {
        all(controller:'*', action:'*') {
            before = {

            }
            after = { Map model ->

            }
            afterView = { Exception e ->

            }
        }
    }
}
All we need to do is fill empty closures, modify filter properties and put some data into MDC.

all is the general name of our filter, as class BasketFilters (plural!) can contain many various filters. You can name it whatever you want, for this post let assume it will be named basketFilter. 

Another thing is change of filter parameters. According to official documentation (link) we can customize our filter in many ways. You can specify controller to be filtered, its actions, filtered urls and so on. In our example you can stay with default option where filter is applied to every action of every controller. If you are interested in filtering only some urls, use uri parameter with expression describing desired urls to be filtered.

Three closures that are already defined in template have their function and they are started in these conditions:

  • before - as name says, it is executed before filtered action takes place
  • after - similarly, it is called after the action
  • afterView - called after rendering of the actions view
Ok, so now we know what are these mysterious methods and when they are called. But what can be done within them? In official Grails docs (link again) under section 7.6.3 there is a list of properties that are available to use in filter.

With that knowledge, we can proceed to implementing filter.

Putting something into MDC in filter


What we want to do is quite easy: we want to retrieve basket number from parameters and put it into MDC in our filter:
class BasketFilters {
    def filters = {
        basketFilter(controller:'*', action:'*') {
            before = {
                MDC.put("basketNumber", params.basketNumber ?: "")
            }
            after = { Map model ->
                MDC.remove("basketNumber")
            }
        }
    }
}

We retrieve basket number from Grails params map and then we put in map under specified key ("basketNumber" in this case), which will be later used in logger conversion pattern. It is important to remove custom value after processing of action to avoid leaks.

So we are putting something into MDC. But how make use of it in logs?


We can refer to custom data in MDC in conversion patter using syntax: %X{key}, where key is our key we used in filter to put data, like:
def conversionPattern = "%d{yyyy-MM-dd HH:mm:ss} %-5p %t [%c{1}] %X{basketNumber} - %m%n"


And that's it :) We've put custom data in log4j MDC and successfully used it in logs to display interesting values.