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Traditionally there are a lot of events happening in the Jenkins organization in Autumn. I would like to share some information about the upcoming hackathons. Online Event: Hacktoberfest As you probably know, there is an ongoing Hacktoberfest event. The Jenkins project is participating in it and everybody is welcome to contribute to Jenkins as a part of this event. The event lasts from October 01 to October 31, and you can can join it at any time. See this blogpost for more information about Hacktoberfest in the Jenkins project. Onsite Hackathons Hacktoberfest is not the only event happening in the Jenkins community this month, there are also a number of upcoming on-site events: Oct 19 - Copenhagen, Denmark Jenkins Configuration as Code hackathon at Day of Jenkins [as code ] Registration: all conference participants can attend Oct 22 - Nice, France - Hackathon at DevOps World - Jenkins World Nice RSVP here Make sure to also attend the Jenkins Contributor Summit on Oct 23 ;) Oct 27 - Beijing, China RSVP here Oct 30 - Neuchatel, Switzerland - Hacktoberfest: Jenkins & Friends event (Swiss Jenkins Area meetup) RSVP here All contributions during these in-person events qualify as Hacktoberfest contributions as well. :) More events will also be announced later in the year, e.g. we traditionally do a hackfest in Brussels after FOSDEM in February. Follow our developer mailing lists and social media to receive announcements.

The Jenkins Contributor summit is where the current and future contributors of the Jenkins project get together. This summit will be on Tuesday, October 23rd 2018 in Nice, France just before Jenkins World. The summit brings together community members to learn, meet and help shape the future of Jenkins. In the Jenkins commmunity we value all types and sizes of contributions and love to welcome new participants. It is free to join, just register here. Topics There are plenty of exciting developments happening in the Jenkins community. The summit will feature a 'State of the Project' update including updates from the Jenkins officers. We will also have updates on the 'Big 5' projects in active development: Jenkins Evergreen Jenkins X Configuration as Code Jenkins Pipeline Cloud Native Jenkins Plus we will feature a Google Summer of Code update, Special Interest Group updates and more! Agenda The agenda is shaping up well and here is the outline so far. 9:00am Kickoff & Welcome with coffee/pastries 10:00am Project Updates 12:00pm Lunch 1.00pm BoF/Unconference 3.00pm Break 3.30pm Ignite Talks 5.00pm Wrap-up 6.00pm Contributor Dinner The BoF (birds-of-a-feather) session will be an opportunity for in depth discussions, hacking or learning more about any of the big 5. Bring your laptop, come prepared with questions and ideas, and be ready for some hacking too if you want. Join in, hear the latest and get involved in any project during the BoF sessions. If you want to share anything there will be an opportunity to do a 5-min ignite talk at the end. Attending is free, and no DevOps World | Jenkins World ticket is needed, but RSVP if you are going to attend to help us plan. See you there!

The Jenkins Contributor summit is where the current and future contributors of the Jenkins project get together. This summit will be on Monday, September 17th 2018 in San Francisco, just before DevOps World | Jenkins World. The summit brings together community members to learn, meet and help shape the future of Jenkins. In the Jenkins commmunity we value all types and sizes of contributions and love to welcome new participants. Register here. Topics There are plenty of exciting developments happening in the Jenkins community. The summit will feature a 'State of the Project' update including updates from the Jenkins officers. We will also have updates on the 'Big 5' projects in active development: Jenkins Evergreen Jenkins X Configuration as Code Jenkins Pipeline Cloud Native Jenkins Architecture Plus we will feature a Google Summer of Code update, and more! Agenda The agenda is shaping up well and here is the outline so far. 9:00am Kickoff & Welcome with coffee/pastries 10:00am Project Updates 12:00pm Lunch 1.00pm BoF/Unconference 3.00pm Break 3.30pm Ignite Talks 5.00pm Wrap-up 6.00pm Contributor Dinner The BoF (birds-of-a-feather) session will be an opportunity for in depth discussions, hacking or learning more about any of the big 5. Bring your laptop, come prepared with questions and ideas, and be ready for some hacking too if you want. Join in, hear the latest and get involved in any project during the BoF sessions. If you want to share anything there will be an opportunity to do a 5-min ignite talk at the end. Attending is free, and no DevOps World | Jenkins World ticket is needed, but RSVP if you are going to attend to help us plan. See you there!

Last week I participated in the Jenkins & Java 10 Online Hackathon. It was my first Jenkins hackathon and I roped in Jonah Graham to do some pair-programming. The hackathon featured JDK Project Jigsaw committers Mandy Chung and Paul Sandoz, as well as Jenkins creator Kohsuke Kawaguchi. It was a great opportunity for me to learn a lot about Jenkins and Java 10. Why Java 10? With the Java 8 EoL data looming, the focus was on the current available version of Java, Java 10. Java 10 offers some nice new features and APIs, not least improved docker container integration. We learned from Paul of a number of projects with Java 10 migration success stories including Elasticsearch, Kafka & Netty. At the beginning of the hackathon week, the Jenkins Pipeline feature would crash out when using Java 10. This was resolved with a number of fixes including the upgrade of the ASM library. Then it was nice to see things up and running with Java 10. Getting up & running The first steps were to do some exploratory testing using Jenkins with Java 10 via Docker, thanks to Oleg for providing clear instructions. This was boringly straightforward as most things worked and we only found one issue to report. Next to try to get some patches in, we needed to set-up a dev environment. The live session gave us what we needed to set up a plugin or core dev environment. One open question we had was whether Jenkins has semantic versioning and API tools to help identify when you might be breaking backwards compatibility. Overall it was straightforward to get a dev environment up and running. Java 10 New APIs The next step was to find an issue which we could help resolve. Many of the Java 10 issues were related to 'Illegal reflective access' from various plugins or third-party libraries. However after investigating a couple, removing these warnings required a good architectural knowledge of the plugin or core code itself. In the end we decided that messing around with classloaders or attempting to upgrade version of jdom was not one for the newbies. Instead we looked at removing reflection in cases of isAccessible calls. We found the ProcessHandle api very useful and a good replacement for some misuse of reflection, and even better it made the code work on Windows too. Mandy also pointed us to look at the Lookup api as possible alternate to findClass calls. Multi-Release JAR Builds Using new APIs is all well and good but presents a problem when you want to maintain backwards compatibility with Java 8. Hence the need for some sort of multi-jar solution - Nicolas De loof proposed one such solution for multi-release jars with Maven for this case. sun.misc.Signal The Java Signal API is being deprecated, but so far no replacement APIs are available for signal handling. Jenkins makes use of the Signal APIs so a big question for the Jigsaw team was whether this would be replaced going forward. Kohsuke pointed out how it is important for Java to maintain this UNIX like behaviour as it shouldn’t matter to end users that Jenkins is written in Java. It seems these APIs will be replaced in due course, they just aren’t there right now. Collaboration, Collaboration, Collaboration It was great to have the discussions with the Jigsaw team. They reminded us how they need to know the Java use cases out there and how their team uses these to feed into their development process. In turn, the hackathon had Jenkins community members participate, for instance easy-jenkins was up and running with Java 10 by the end of the week. The hackathon had a great feeling of community spirit and was a reminder why collaborations with communities and also between different communities can be powerful and fun for all involved. At the end of the week Jonah and I were both happy that we made our first Jenkins contributions (which were reviewed and merged quickly). Thanks to all who participated and made it highly enjoyable, especially Oleg for great organization. I look forward to the next one!

This week we have a Jenkins & Java 10 Online Hackathon. This is an open online event, where we work together on Jenkins core and plugins in order to find and fix compatibility issues, share experiences and have some fun. Everybody is welcome to join, independently of their Jenkins experience and amount of time they have available. After the kick off on Monday Jenkins contributors have been working on Java 10 and Java 11 support in Jenkins. We have already received contributions from 12 hackathon participants, and the number keeps growing. There are still 3 days ahead, but we have already achieved some important results we want to share. Jenkins Pipeline One of our major efforts over last 2 days was to get Jenkins Pipeline working on Java 10+. When the hackathon started Jenkins Pipeline was not working at all, and it was a major blocker for Java support and for exploratory testing in particular. We’ve been working together with Sam van Oort and Devin Nusbaum to fix the libraries in the Jenkins core, Pipeline: Support plugin and Docker packaging. Just to summarize the result of two days in one screenshot…​ Yes, we have got it running! Over two days we have got from the "Pipeline Crashes Immediately" state to the situation when the most of key Pipeline features are operational, including Scripted and Declarative Pipeline, Blue Ocean, shared libraries and dozens of plugins being used in the Jenkins plugin build flow. There is still a lot of work to do to get the changes finalized, but Jenkins Pipeline is available for testing on Java 10 and 11 now. If you want to try it out, you can use a new jenkins/jenkins-experimental:blueocean-jdk10 image we have created. It bundles all the required patches, so you can just run the following command to get started: docker run -p 8080:8080 -p 50000:50000 jenkins/jenkins-experimental:blueocean-jdk10 If you want to try more complex scenarions, see the Running Jenkins with Java 10 and 11 blogpost and List of Required patches. What else? Although Pipeline is the most visible change, there are other ongoing activities: Devin Nusbaum explored plugin startup issues we had with JDK 11ea+17 and confirmed that we need to upgrade our images to JDK 11ea+18 Gianpaolo Macario is working on adopting the Java 10 experimental images in his easy-jenkins project Sam van Oort and Devin Nusbaum are working on getting plugin build and test flows when using JDK 10 with Maven Nicolas de Loof is working on cleaning up Illegal reflective access warnings in Jenkins components, using the new Fields micro-library Olivier Lamy and Nicolas de Loof are updating the Animal Sniffer plugin for Maven to make it compatible with Java 9 and above Kohsuke Kawaguchi has released a repackaged version of ASM 6.2 we use in the project Last but not least, Liam Newman and Tracy Miranda helped us a lot to run the meetings and to get this hackathon organized There are also other contributors working on exploratory testing and reporting defects they discover. See our status doc for the full list. What’s next? Tomorrow we will have 2 sessions: At 8AM UTC we will have a sync-up. According to the requests from hackathon paticipants, we will have an intro session to Jenkins development for newcomers YouTube link At 4PM UTC we will have a meeting with key JDK Project Jigsaw committers Mark Reinhold, Mandy Chung and Paul Sandoz will join us to talk about Java 10/11 adoption YouTube link We will also post participant links in our Gitter channel 15 minutes before the meetings. If you have any questions, please join the meetings or raise questions in the chat during the call. Can I still join the hackathon? Yes, you can! It is possible to hop in and hop off at any time. Just respond to the registration form, join our Gitter channel and start hacking/testing. We also have a number of newbie-friendly issues you can start from. See our Kick-off session and slides for quick start guidelines. Links Developer mailing list Hackathon sync-up document Running Jenkins with Java 10 and 11 Jenkins Online Meetup page

On behalf of the Jenkins Events Team, I would like to invite you to the “Jenkins & Java 10 Online Hackathon” which will take place from June 18th to 22nd. We will be working together on Jenkins core and plugins in order to find and fix compatibility issues, share experiences and have some fun. Everybody is welcome to join, independently of their Jenkins experience and amount of time they have available. If you are interested in participating in the hackathon, please sign-up in this form. Background Java 9 has recently been end-of-lifed, Java 10 is in GA, and Java 11 is in early beta. Jenkins project currently requires Java 8 to run reliably, and there are some known compatibility issues with higher Java versions. During the Jenkins World 2017 Hackathon, Mark Waite and Baptiste Mathus spent some time exploring Java 9 compatibility in Jenkins. We are currently tracking compatibility issues in the JENKINS-40689 EPIC, but there are likely many unknown issues in Jenkins core, plugins and in libraries we use in the project. We would like to continue their effort and work on Java 10+ support. Objectives and Scope As I have said above, the goals are to explore/fix compatibility issues, share experiences and have fun. We DO NOT plan to make Jenkins fully compatible with Java 10+ during the hackathon, but we will try to integrate fixes and make them available. Since the announcement of the Hackathon in the mailing list, we have got a number of registrations from contributors working on several project areas. We will split our work to several areas: Jenkins core and Remoting Pipeline Engine Plugins (e.g. Git plugin or any plugin you want to work on) Exploratory testing for Java 10 and beyond In order to organize the effort, we have created a java10_hackathon label in Jenkins JIRA. If you are interested in particular tasks, please assign them to yourself and add the label. Organization Currently the event is in the planning stage. We will be using the Developer mailing list for synchronization before the event. What will we have? Communications in #jenkins-hackhouse IRC and in the Jenkins Gitter channel Daily recorded sync-up calls in Hangouts Knowledge transfer sessions during the event We also want to prepare some special swag for active participants. If you have reached this part of the blogpost, you have probably seen the logo ;) Links Registration Developer mailing list Hackathon sync-up document Running Jenkins with Java 10 and 11 JIRA: Java 10 compatibility JIRA: Java 11 compatibility JIRA: Hackathon tasks

On behalf of the Jenkins GSoC team and mentors, I would like to welcome Shenyu Zheng, Udara De Silva, Pham Vu Tuan and Abhishek Gautam. They will be working on Google Summer of Code projects in the Jenkins organization, and they have already done some contributions. This year we have the following projects: Code Coverage API Plugin - create a new API Plugin to unify existing Code Coverage plugins and provide new features. Student: Shenyu Zheng from Henan University, Kaifeng, China Mentors: Steven Christou and Supun Wanniarachchi Electronic Design Automation Plugins - create plugins for open-source Electronic Design Automation tools for synthesis, simulation and coverage analysis (iVerilog, covered, Yosys). Student: Udara De Silva from University of Akron, Ohio, USA Mentors: Martin d’Anjou and Oleg Nenashev Jenkins Remoting over Message Bus/Queue - add support of a popular message queue/bus technology (RabbitMQ or Kafka) as a fault-tolerant communication layer in Jenkins. Student: Pham Vu Tuan from Nanyang Technological University, Singapore Mentors: Oleg Nenashev and Supun Wanniarachchi Simple Pull-Request Job Plugin - add ability to define Jenkins jobs as YAML files stored in SCM, integrate it with existing plugin ecosystem. Student: Abhishek Gautam from Visvesvaraya National Institute of Technology, Nagpur, India Mentors: Jeff Knurek, Kristin Whetstone and Willy Aguirre During next 4 weeks project teams will be reaching out to potential stakeholders in order to establish connections and to get comments regarding their project designs. If you are interested in the projects, please join discussions in the Developer mailing lists and project meetings once they get scheduled. Please also expect expect more detailed blogposts about the projects soon. If you are interested to know more about GSoC in Jenkins, you can find information, timeline and communication channels here.

We are happy to announce that Jenkins project has been accepted to Google Summer of Code 2018. This year we invite students and mentors to join the Jenkins community and work together on various initiatives: core, plugins, development tools and infrastructure. Our mentors have already created some project ideas. For example, you are welcome to work on the new Configuration-as-Code initiative or to help creating standard API for Code Coverage plugins. If you like test automation, there is a proposal to Jenkins Acceptance Test Harness. Over the next weeks we plan to extend this list by new even more project ideas. All information about the Jenkins GSoC is available on its subproject page. I am a student. How do I apply? See Information for students for application guidelines. First step is to join discussions in the mailing lists in order to introduce yourself, establish connections with the community and potential mentors. The application period starts on March 12 and ends on March 27, but don’t let it misguide you! Use time before application to discuss project ideas/proposals with mentors and to process their feedback. To create a better proposal, we also recommend to study Jenkins and to do some contributions in the area of your project proposal. Not satisfied by the current project ideas? You can propose your own idea in the developer mailing list. I want to be a mentor. Is it too late? It’s not! If you are passionate about open-source and Jenkins, we invite you to join the mentors team. You can either propose a new project idea or join an existing one. See Call for Mentors and Information for mentors for details. This year mentorship does NOT require strong expertise in Jenkins development. The objective is to guide students and to get involved into the Jenkins community. GSoC org admins will help to find advisers if special expertise is required. Important dates Mar 05 - deadline for new GSoC project idea proposals Mar 12 - student application period starts Mar 27 - deadline for student applications Apr 23 - accepted projects announced, community bonding starts May 14 - coding period starts Aug 06 - end of the coding period See the GSoC Timeline for more info. In the Jenkins project we will also organize special events during and after GSoC (e.g. at Jenkins world). P.S: I am going to create a special GSoC 2018 edition of swags for mentors and students. Do not miss them ;)