To define a hostname for YouTrack, you have to edit file youtrack.jar!/jetbrains/mps/webr/standalone/runtime/standalone.xml. In the file, locate the following code block:
Then, add the line <Set name="host">desired hostname</Set>. That's it!
For example, to set hostname to the 127.0.0.1, the block should look as follows:
If you get the error "JAR file signature violated":
If, after you change the content of JAR file, youtrack.jar won't start and you get the error "JAR file signature violated", then you need delete the violated signature:
youtrack.jar!/META-INF/JETBRAIN.SF and youtrack.jar!/META-INF/JETBRAIN.RSA files.