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![20 Reactions from the Gerrit mailing list … So i checked it out and tried it, and what should i say ... Wow, it rocks! ;-) Combined with new and shiny Plugin API the code is really short. So i started new repo on gh [1] and created two working plugins [2], [3], and sure would add more, so to say, cookbook-groovy-plugin: $>ssh gerrit review approve I59302cbb $>Approve change: I59302cbb. What do YOU think ? ](https://image.slidesharecdn.com/gerrit-scripting-scala-groovy-plugin-140321092512-phpapp02/75/Gerrit-Code-Review-how-to-script-a-plugin-with-Scala-and-Groovy-20-2048.jpg)
![22 HOW can I get Gerrit with scripting plugins ? Download the Gerrit master with scripting extensions from: http://ci.gerritforge.com/job/Gerrit-master-scripting/lastSuccessfulBuild/artifact/buck- out/gen/gerrit-scripting.war Run Gerrit init and say Y for installing the Scala and Groovy scripting plugins providers: *** Plugins *** Install plugin groovy-provider version v2.9-rc1-325-g96d0d43 [y/N]? Y Install plugin scala-provider version v2.9-rc1-325-g96d0d43 [y/N]? y You may want to increase the JVM PermGen on gerrit.config when loading/unloading scripting plugins [container] javaOptions = -XX:MaxPermSize=1024m](https://image.slidesharecdn.com/gerrit-scripting-scala-groovy-plugin-140321092512-phpapp02/75/Gerrit-Code-Review-how-to-script-a-plugin-with-Scala-and-Groovy-22-2048.jpg)
![26 List projects via REST API $ cat - > ~/gerrit/plugins/projects-1.0.scala import com.google.inject._ import com.google.gerrit.extensions.annotations._ import com.google.gerrit.server.project._ import javax.servlet.http._ import scala.collection.JavaConversions._ @Singleton @Export("/") class Projects @Inject() (val pc: ProjectCache) extends HttpServlet { override def doGet(req: HttpServletRequest, resp: HttpServletResponse) = resp.getWriter print "[" + (pc.all map ( """ + _.get + """ ) mkString ",") + "]" } ^D https://gist.github.com/lucamilanesio/9687133](https://image.slidesharecdn.com/gerrit-scripting-scala-groovy-plugin-140321092512-phpapp02/75/Gerrit-Code-Review-how-to-script-a-plugin-with-Scala-and-Groovy-26-2048.jpg)
![29 Scalable in-process hooks $ cat - > ~/gerrit/plugins/inprochook-1.0.scala import org.slf4j.LoggerFactory._ import com.google.inject._ import com.google.gerrit.common._ import com.google.gerrit.server.events._ import com.google.gerrit.extensions.registration.DynamicSet @Singleton class ListenToChanges extends ChangeListener { val log = getLogger(classOf[ListenToChanges]) override def onChangeEvent(e: ChangeEvent) = e match { case comm: CommentAddedEvent => log info s"${comm.author.name} said '${comm.comment}' " + s"on ${comm.change.project}/${comm.change.number}'" case _ => } } class HooksModule extends AbstractModule { override def configure = DynamicSet bind(binder, classOf[ChangeListener]) to classOf[ListenToChanges] } ^D Less CPU overhead (no exec/fork) faster and scalable Works on behalf of user thread identity Access Gerrit injected objects (Cache, ReviewDb, JGit) https://gist.github.com/lucamilanesio/9687154](https://image.slidesharecdn.com/gerrit-scripting-scala-groovy-plugin-140321092512-phpapp02/75/Gerrit-Code-Review-how-to-script-a-plugin-with-Scala-and-Groovy-29-2048.jpg)
![30 Commit message validation $ cat - > ~/gerrit/plugins/commitheadline-1.0.scala import scala.collection.JavaConversions._ import com.google.inject._ import com.google.gerrit.extensions.annotations._ import com.google.gerrit.server.git.validators._ import com.google.gerrit.server.events._ @Singleton @Listen class HasIssueInCommitHeadline extends CommitValidationListener { override def onCommitReceived(e: CommitReceivedEvent) = "[A-Z]+-[0-9]+".r findFirstIn e.commit.getShortMessage map { issue => Seq(new CommitValidationMessage(s"Issue: $issue", false)) } getOrElse { throw new CommitValidationException("Missing JIRA-ID in commit headline") } } ^D Native pattern-matching support Java regex available out-of-the box Support for Optional values (map/getOrElse) https://gist.github.com/lucamilanesio/9687174](https://image.slidesharecdn.com/gerrit-scripting-scala-groovy-plugin-140321092512-phpapp02/75/Gerrit-Code-Review-how-to-script-a-plugin-with-Scala-and-Groovy-30-2048.jpg)
Uploaded byLuca Milanesio
Gerrit Code Review: how to script a plugin with Scala and Groovy
This document discusses scripting plugins for Gerrit code review. It describes how plugins can now be written in Groovy or Scala by creating a simple class file and placing it in the plugins directory. This allows defining new SSH commands or REST APIs with just a few lines of code. The document outlines several examples including creating branches, listing projects, and validating commit messages. It announces plans to further develop scripting plugin support at the next Gerrit hackathon with the goal of merging it into the core Gerrit codebase.
Gerrit Code Review: how to script a plugin with Scala and Groovy
- 1.
- 2. 2 About Luca • LucaMilanesio Co-founder of GerritForge • over 20 years of experience in Agile Development SCM, CI and ALM worldwide • Contributor to Jenkins since 2007 (and previously Hudson) • Git SCM mentor for the Enterprise since 2009 • Contributor to Gerrit Code Review community since 2011
- 3. 3 About GerritForge Founded in2009 in London UK Mission: Agile Enterprise Products:
- 4. 4 Agenda Where wecome from ? 2 years ago: Gerrit plugins We want more plugins Create a plugin in 60 seconds What, how and when are coming? Plugins showcase
- 5. 5 WHO REMEMBERS THIS ? GitTogether2011 Gerrit 2.2.x
- 6. 6 Why don’t we introduceplugins ? They have been so successful with Jenkins
- 7. 7 Gerrit Hackathon 7th ofMay 2012 The first “helloworld” plugin was born
- 8. 8 WHO REMEMBERS THIS? Gerrit Summit 2012 Ver. 2.5.x
- 9. 9 Gerrit Plugins Growth in 2years 50
- 10. 10 Can we domore ? Let's ask Jenkins
- 11.
- 12.
- 13. 13 That would bevery useful for Gerrit Administrators to be able to write quick automation scripts for their daily tasks. I would prioritize groovy plugin more for the popularity of groovy scripting. I think adding a "scripting language plugin" to support plugins written in scripting languages is a very good idea Hi all, I was thinking about extending Gerrit capabilities to load plugins / extensions by providing "wrapper" for other JVM languages. So … we asked the Community I would prefer scala, because I've already written my plugins with it. imho the builld process is the main impediment.
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- 15. 15 NO STEPS, NOBUILD … just do it ! $ cat - > ~/gerrit/plugins/hello-1.0.groovy import com.google.gerrit.sshd.* import com.google.gerrit.extensions.annotations.* @Export("groovy") class GroovyCommand extends SshCommand { public void run() { stdout.println "Hi from Groovy" } } ^D This sample has 190 chars: you need to type at least 3.2 chars/sec to complete the sample in only one minute https://gist.github.com/lucamilanesio/9687053
- 16. 16 IS THAT TRUE? Let’s check on Gerrit $ ssh –p 29418 user@localhost gerrit plugin ls Name Version Status File ---------------------------------------------------------------------- hello 1.0 ENABLED hello-1.0.groovy Gerrit auto-detects the new Groovy file under $GERRIT_SITE/plugins, invoke the interpreter and auto-wrap the class into a self-contained Gerrit plugin. Groovy class is compiled into byte-code BUT is slower than native Java plugin.
- 17. 17 DOES IT REALLYWORK ? $ ssh –p 29418 user@localhost hello groovy Hi from Groovy No magic … IT IS ALL REAL ! Plugin name (hello) comes from the script filename. A new SSH command (groovy) has been defined in Gerrit associated to the Groovy script loaded.
- 18. 18 What about Scala? Just do it again ! $ cat - > ~/gerrit/plugins/hi-1.0.scala import com.google.gerrit.sshd._ import com.google.gerrit.extensions.annotations._ @Export("scala") class ScalaCommand extends SshCommand { override def run = stdout println "Hi from Scala" } ^D Scala is more concise with just 178 chars : you can take it easy with 2.9 chars/sec to type it a minute https://gist.github.com/lucamilanesio/9687092
- 19. 19 You have nowtwo plugins loaded $ ssh –p 29418 user@localhost gerrit plugin ls Name Version Status File ---------------------------------------------------------------------- hello 1.0 ENABLED hello-1.0.groovy hi 1.0 ENABLED hi-1.0.scala There are no differences for Gerrit between Java, Groovy or Scala plugins: they have the same dignity and power. Scala compiler takes longer but byte-code runs at the same speed as a native Java plugin!
- 20. 20 Reactions from theGerrit mailing list … So i checked it out and tried it, and what should i say ... Wow, it rocks! ;-) Combined with new and shiny Plugin API the code is really short. So i started new repo on gh [1] and created two working plugins [2], [3], and sure would add more, so to say, cookbook-groovy-plugin: $>ssh gerrit review approve I59302cbb $>Approve change: I59302cbb. What do YOU think ?
- 21. 21 WHAT can scriptingplugins do now ? 1. Define new SSH commands 2. Define new REST APIs 3. Listen to Gerrit events
- 22. 22 HOW can Iget Gerrit with scripting plugins ? Download the Gerrit master with scripting extensions from: http://ci.gerritforge.com/job/Gerrit-master-scripting/lastSuccessfulBuild/artifact/buck- out/gen/gerrit-scripting.war Run Gerrit init and say Y for installing the Scala and Groovy scripting plugins providers: *** Plugins *** Install plugin groovy-provider version v2.9-rc1-325-g96d0d43 [y/N]? Y Install plugin scala-provider version v2.9-rc1-325-g96d0d43 [y/N]? y You may want to increase the JVM PermGen on gerrit.config when loading/unloading scripting plugins [container] javaOptions = -XX:MaxPermSize=1024m
- 23.
- 24. 24 Create a branchthrough Gerrit API $ cat - > ~/gerrit/plugins/branch-1.0.groovy import com.google.gerrit.sshd.* import com.google.gerrit.extensions.annotations.* import com.google.gerrit.extensions.api.* import com.google.gerrit.extensions.api.projects.* import com.google.inject.* import org.kohsuke.args4j.* @Export("create") @CommandMetaData(name = "create-branch", description = "Create branch") class CreateBranch extends SshCommand { @Inject GerritApi api @Argument(index = 0, usage = "Project name", metaVar = "PROJECT") String projectName @Argument(index = 1, usage = "Branch name", metaVar = "BRANCH") String branchName @Argument(index = 2, usage = "Branch point sha1", metaVar = "SHA1") String sha1 void run() { BranchInput branch = new BranchInput() branch.revision = sha1 api.projects().name(projectName).branch(branchName).create(branch) stdout.println("Branch created: " + branchName) } } ^D https://gist.github.com/lucamilanesio/9687118
- 25. 25 Script classes get PluginsGuice Injections (but cannot add Guice Modules)
- 26. 26 List projects viaREST API $ cat - > ~/gerrit/plugins/projects-1.0.scala import com.google.inject._ import com.google.gerrit.extensions.annotations._ import com.google.gerrit.server.project._ import javax.servlet.http._ import scala.collection.JavaConversions._ @Singleton @Export("/") class Projects @Inject() (val pc: ProjectCache) extends HttpServlet { override def doGet(req: HttpServletRequest, resp: HttpServletResponse) = resp.getWriter print "[" + (pc.all map ( """ + _.get + """ ) mkString ",") + "]" } ^D https://gist.github.com/lucamilanesio/9687133
- 27. 27 Scala is COMPACT +FUNCTIONAL NOTE: for Guice injection @Inject() before constructor vals
- 28.
- 29. 29 Scalable in-process hooks $cat - > ~/gerrit/plugins/inprochook-1.0.scala import org.slf4j.LoggerFactory._ import com.google.inject._ import com.google.gerrit.common._ import com.google.gerrit.server.events._ import com.google.gerrit.extensions.registration.DynamicSet @Singleton class ListenToChanges extends ChangeListener { val log = getLogger(classOf[ListenToChanges]) override def onChangeEvent(e: ChangeEvent) = e match { case comm: CommentAddedEvent => log info s"${comm.author.name} said '${comm.comment}' " + s"on ${comm.change.project}/${comm.change.number}'" case _ => } } class HooksModule extends AbstractModule { override def configure = DynamicSet bind(binder, classOf[ChangeListener]) to classOf[ListenToChanges] } ^D Less CPU overhead (no exec/fork) faster and scalable Works on behalf of user thread identity Access Gerrit injected objects (Cache, ReviewDb, JGit) https://gist.github.com/lucamilanesio/9687154
- 30. 30 Commit message validation $cat - > ~/gerrit/plugins/commitheadline-1.0.scala import scala.collection.JavaConversions._ import com.google.inject._ import com.google.gerrit.extensions.annotations._ import com.google.gerrit.server.git.validators._ import com.google.gerrit.server.events._ @Singleton @Listen class HasIssueInCommitHeadline extends CommitValidationListener { override def onCommitReceived(e: CommitReceivedEvent) = "[A-Z]+-[0-9]+".r findFirstIn e.commit.getShortMessage map { issue => Seq(new CommitValidationMessage(s"Issue: $issue", false)) } getOrElse { throw new CommitValidationException("Missing JIRA-ID in commit headline") } } ^D Native pattern-matching support Java regex available out-of-the box Support for Optional values (map/getOrElse) https://gist.github.com/lucamilanesio/9687174
- 31. 31 And there ismore … audit events download commands project and group events message of the day Prolog predicates auth backends avatars
- 32. 32 WHEN scripting pluginswill be included in Gerrit ? Hackathon #6 24-26th March we will keep on hacking on Gerrit MISSION: improve, stabilise and merge scripting plugins into Gerrit master ! TARGET VERSION: Gerrit Ver. 2.10 (?)
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- 34. Try it on-line(with scripting): http://gerrithub.io/login Read the Gerrit book: http://gerrithub.io/book Keep in touch: http://gitenterprise.me Learn more about Gerrit with 20% OFF Book discount for Gerrit User Summit 2014 Book PROMO-CODE: LGCRB20 eBook PROMO-CODE: LGCReB20