How I moved to Java 11 for my Sakai development
Charles Severance
Since Sakai has moved to Java 11 for the Sakai 22 and later releases, we will need to update our developer environments. I also made the following changes.
- Use the org.mariadb database connector and Hibernate dialect (even if I am using MySQL 5.7). The connector is free and automatically deployed by Sakai so there is no extra fuss downloading the com.mysql connector and hand-installing it in Tomcat.
- Upgrade Maven to 3.8.1 or later
- On my fresh-install Linux environments I am switching to MariaDB as my dev database server. If I have an existing MySQL (i.e. MAMP on Mac or Aurora on AWS) I will just keep using it but switch to the MariaDB connector.
I have setup and tested four different environments in the post-JDK11 environment:
- Matt Jones’ docker-build solution. This is very cool – especially for Windows. Matt mounts folders from your computer’s file system into his (build/database/sakai) docker containers so you can edit files outside of the docker containers and then build / run all inside docker containers with a zero footprint install on your computer other than docker itself. Also your database persists even when you have no docker containers running. The container and mounted files slows this down a bit – but if you have a super fast Windows or modern MacBook box with a lot of memory and SSD, it is plenty quick.
- My MacBook running natively installed Java, Tomcat, and MAMP using my sakai-scripts code. For Mac development it is faster than Matt’s docker solution especially for my circa-2013 MacBooks that I refuse to upgrade.
- A simple self contained Ubuntu image running under docker using my sakai-scripts code. I use this to make sure I can quickly test my scripts or Sakai’s build under ubuntu without spinning up an EC2 node or DigitalOcean Box. This is different from Matt’s docker approach because everything (including the MariaDB server and data) is in the docker – it is nice for quick tests because it is a zero-install other than docker on your main computer.
- An ubuntu server running on Digital Ocean / EC2 using my sakai-scripts code like https://dev1.sakaicloud.com
If you want to figure out things like shell settings or other configuration to adapt your own setup, you can take a look at some of the files in my sakai-scripts repo. If you used these scripts before, there was a complex step of getting all the environment variables set in your profile (mac or linux). Now each script sets its environment variable and does its thing – much better and easier to fix / upgrade when things change a little.
You can examine these scripts and extract bits to use in your environment.
- Start with the README.md it contains the overall outline of manual and automated steps. This shows how to setup (a) a MackBook, (b) ubuntu in a stand-alone docker, and (c) ubuntu on a stand-alone server.
- Take a look at ubuntu.sh to see what prerequisites are needed on ubuntu. Because I use sdman the installs are much simpler – thanks Matt and Earl for teaching us about this. Using sdman also allows you to switch back to JDK-8 if you need to. It is the logical equivalent of Python virtual environments.
- Take a look at qmv.sh to see things like needed environment variables to make maven work. Without these maven will run out of memory whilst building.
- Take a look at start.sh to see the relatively complex set of environment variables needed to set up Java to run Sakai. These variables are adapted from the Matt / Earle recommendations. Matt designed these to be tweak able and there are some examples of things like setting up a debugger if you want that.
I hope you find this helpful. I would also like to explore moving these scripts and Matt’s docker stuff into the core repository in a “dev” folder. It is kind of silly to have these in hard-to-find locations in contrib and my repo.