Developer Environment Setup

These instructions outline how to install Opencast. This is meant for developers. For the installation of a production cluster, take a look at the admin guides.

Warning: This probably won´t work with Windows.


$ git clone
$ cd opencast
$ ./mvnw clean install -Pdev
$ cd build/opencast-dist-develop-*
$ ./bin/start-opencast

Opencast will then listen on

Default credentials are:

Where * is the version number of the distribution.

Clone Opencast

You can get the Opencast source code by cloning the Git repository.

Cloning the Git repository:

$ git clone

Install Dependencies

Please make sure to install the following dependencies.


ffmpeg >= 3.2.4
maven >= 3.6

Required as a service for running Opencast:

elasticsearch = 7.9.x

Required for some services. Some tests may be skipped and some features may not be usable if they are not installed. Hence, it's generally a good idea to install them.

tesseract >= 3
hunspell >= 1.2.8
sox >= 14.4

Build Opencast

You can now build opencast by changing into your opencast directory and running:

$ ./mvnw clean install [Options]

After the successful compilation you can start opencast with:

$ ./build/opencast-dist-develop-*/bin/start-opencast

Where * is the version number of the distribution.

Build options

Assembly profiles

Besides the default dist Maven profile, you can specify other profiles to create different builds. Activate these profiles using:

profile description
-Pdev Create a single allinone distribution and unpack it
-Pnone Do not create any distribution

You can only use one of these profiles at a time.

Build options

The following options can be used to customize the build process. They can be used in combination with the assembly profiles.

Option Description
-DtrimStackTrace=false Do not trim stack traces in the logs
-DskipTests=true Skip tests
-T 1.0C Use multiple threads for building (Experimental)

Build Single Modules

When working on a single Opencast module, it can be extremely helpful having the new built version automatically included in the Opencast OSGi infrastructure. This can be achieved by watching the module with the bundle:watch command in Karaf. The procedure would be as follows:

To see this technique in action, you can watch the following short video:

The updated bundles are only available in the currently running Karaf instance. To create an Opencast version that contains your changes permanently, you have to run ./mvnw install in the assemblies directory again.

In several cases the bundle:watch can put Karaf in an unstable condition, as dependencies between bundles will not correctly be restored after the new bundle has been deployed.


Build enabling multiple threads (Experimental)

Building with multiple threads decreases the build time significantly. If you want to enable multiple threads, you can use the following command:

$ ./mvnw clean install -T 1.0C -DskipTests -Pnone 
&& cd assemblies && ./mvnw install -T 1.0C -Dskiptests -Pdev  
&& cd ..
$ ./build/opencast-dist-develop-*/start-opencast

Multiple threads build have not been thoroughly tested and may cause runtime problems or unexpected behavior. We don't advise using this feature for production.

Useful Commands for Testing Purposes

For a quick build, you can use the following command to skip Opencast's tests.

$ cd opencast
$ ./mvnw clean install -Pdev -DskipTests

To see the whole stacktrace of the installation you can use the following command to disable the trimming.

$ cd opencast
$ ./mvnw clean install -DtrimStackTrace=false

If you want to start opencast in debug mode, you could use the debug argument:

$ cd build/opencast-dist-develop-*/bin && ./start-opencast debug

Common Build Errors or Fixes

NPM Access Error

To fix a NPM access error (example), you can run

$ sudo chown -R $USER:$(id -gn $USER) ~/.config && sudo chown -R $USER:$(id -gn $USER) ~/.npm

JDK Version

Some IDEs attempt to use the most recent version of the JDK. Make sure that your IDE uses JDK 11.

While you can use any IDE or editor you like, we recommend the following tools.

IntelliJ IDEA IDE Community Edition

Install it by downloading and following the manufacturer guide, select Community Edition:

IntelliJ IDEA Community Edition

Import Opencast

Follow the next steps, if you want to import opencast correctly

Now Idea should import the projects, it could take some time, you can make it faster by following this.

Setup Code Style

Import the opencast code style configuration by following the steps

Setup CheckStyle

Check style is one of the tools we use to ensure code quality. Not following the check style rules will produce build errors. To use it in IntelliJ, follow these steps:

To use the plugin, you can run manually the check-style plugin through the menu View → Tool Windows → Checkstyle.

Now your IDE should be ready for developing.

Slow IntelliJ IDEA Fix

Edit following file

$ sudo nano /etc/sysctl.conf

and copy this text into it

fs.inotify.max_user_watches = 524288

Apply your changes with

$ sudo sysctl -p --system

Visual Studio Code Editor

We use VS code for mainly:

Install it by downloading and following the manufacturer guide:

Recommended Extensions are: