If TEZ builds in your system, you are ready to build TEZ ui.
On building tez, the ui target files also would be created as the ui is now a part of tez build.
Building
Just run mvn clean package [-DskipTests] from tez for a complete build, or from tez/tez-ui folder for a UI only build. Click here to know more about the tez build process.
Note: If you face any build error denoting the absence of any node package or bower component then delete target, node, node_modules and bower_components directories.
Build Outputs:
All the build related files can be found inside tez/tez-ui/target.
On build two files will be created, a web tarball and a tomcat war. Name of the file would be tez-ui-{version}-SNAPSHOT-web.tar.gz, and tez-ui-{version}-SNAPSHOT.war respectively. Content of the folder tez-ui-0.6.0-SNAPSHOT is what gets packages.