Databus Maven Plugin

User Manual

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Data Dependencies for Maven

Our goal is to align the data and software lifecycle. We created a Maven plugin that can upload output of software, e.g. the DBpedia Information Extraction Framework to the Databus platform. The other tools can include it again, just like software dependencies via Maven Central and Archiva. See the Databus Client and Databus Derive Plugin for data dependencies and automating software with data. The plugin was developed to use the features of the Maven software build automation tool for data releases and metadata generation. Once configured properly (1-3 hours), data can be released and re-released systematically in minutes.



License of the software is AGPL with intended copyleft. We expect that you spend your best effort to commit upstream to make this tool better or at least that your extensions are made available again. Any contribution will be merged under the copyright of the DBpedia Association.

Development notes

  • configuration values taken from Maven are configured in Properties.scala, use its 'sub-trait' Locations.scala to derive filesystem locations from these and Parameters.scala to compute all other values derived from the original Maven properties (refactoring into this separation is not yet complete, but please heed this guidelines for additional configuration-derived fields nontheless)

  • Datafile.scala is a quasi decorator for files, use getInputStream to open any file

  • Use the issue tracker, do branches instead of forks (we can give access), we will merge with master


To set defaults for the plugin we developed a parent pom.xml in the super pom folder. All other pom.xml can use it. Devnote: When uploading to archiva, select pomFile for pom.xml and leave generate pom unchecked

Maven Archiva

We are running a Maven Archiva for Snapshots. New snapshots can be deployed with mvn deploy as configured in the pom.xml. Password is needed to be entered in ~/.m2/settings.xml


databus-shared-lib / Local install works, travis will show build error

databus-shared-lib is a co-developed library. If you update it, travis will fail. Travis chaches the shared lib every 6 hours, so you need to flush the cache manually or wait 6 hours

Download from fails, no dependency information available

Note: this section can be removed after completion of Possible reason: we have installed a dev archiva for now. Depending on your org's network configuration, code might only be accepted from Maven Central and local/allowed maven repos.

  • [WARNING] The POM for org.dbpedia.databus:databus-maven-plugin:jar:1.0-SNAPSHOT is missing, no dependency information available

  • Could not resolve dependencies for project org.dbpedia.databus:databus-maven-plugin:maven-plugin:1.0-SNAPSHOT: Failure to find org.dbpedia.databus:databus-shared-lib:jar:0.1.4

Can potentially fixed by locally installing the shared-lib:

  • Download Jar:

  • Install dependency:

Then clone the repo and run mvn install which will install the databus-maven-plugin locally

databus plugin goals are not found after installing the plugin via sources (mvn install)

[ERROR] Could not find goal 'metadata' in plugin org.dbpedia.databus:databus-maven-plugin:1.1-SNAPSHOT among available goals -> [Help 1]
org.apache.maven.plugin.MojoNotFoundException: Could not find goal 'metadata' in plugin org.dbpedia.databus:databus-maven-plugin:1.1-SNAPSHOT among available goals 

Try to wipe (make a copy of it and then delete the original) your m2 (maven local repository) and then build it again.

BUILD FAILURE, no mojo-descriptors found (when using mvn install to install the databus-maven-plugin)

This is most likely caused by using an old maven version (observed in version 3.0.5) A workaround for this would be replacing:




in databus-maven-plugin/pom.xml

UTF-8 - Encoding Errors in the produced data

On Unix: run: grep "LC_ALL" .* in your /root/ directory and make sure

.bash_profile:export LC_ALL=en_US.UTF-8
.bashrc:export LC_ALL=en_US.UTF-8

is set.

[ERROR] org.scalatra.HaltException at data deploy

Its possible you messed up at creating your webid (especially if you have multiple names in the webid) and used the wrong SAN in the cert.config. Check if your SAN is correct by using openssl x509 -in certificate.crt -text -noout on your .crt file. If you just have the pkcs12 file use openssl pkcs12 -in [yourfile.pfx] -clcerts -nokeys -out [drlive.crt] to generate it. Check if the SAN matches the one you used in the webid.ttl and if not change the cert.config and generate the pkcs12 file again.

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