Starting jetty outside of ${jetty.home} in Windows with logback - jetty

Question

My goal is to set jetty to run as a service and figured I should have it run in command line first. My current aim is to be able to run jetty from root path. Once that's done, I can then set the same command to run as a service via https://nssm.cc/.
The issue
The webapp I am deploying in this Jetty instance uses logback to manage it's logging <file>logs/app.log</file>
This works as expected.
C:\jetty>java -jar start.jar
This does not C:\>java -jar C:\jetty\start.jar. (Note the different cmd path). Jetty can't figure out correct paths for log files. After some testing, I was able to rectify the path issue but still jetty is complaining about not being able to find the log file, even though I see it exists. So, permissions issue perhaps? I go ahead and give everyone full read and write access to the entire folder. No dice, still the same error.
Command I run now
C:\>java -Djetty.base=C:\jetty -Duser.dir=C:\jetty -jar C:\jetty\start.jar but the error persists.
....
12:11:51,095 |-INFO in ch.qos.logback.core.FileAppender[FILE] - File property is set to [logs/app.log]
12:11:51,111 |-ERROR in ch.qos.logback.core.FileAppender[FILE] - Failed to create parent directories for [C:\jetty\logs\app.log]
12:11:51,111 |-ERROR in ch.qos.logback.core.FileAppender[FILE] - openFile(logs/app.log,true) call failed. java.io.FileNotFoundException: logs\app.log (The system cannot find the path specified)
at java.io.FileNotFoundException: logs\app.log (The system cannot find the path specified)
....
Jetty version is 9.4.9.v20180320

Answer 1

Create a proper ${jetty.base} directory, outside of of the ${jetty.home} directory.
Next, get yourself a fresh copy of jetty-home (or the jetty-distribution which really only adds documentation, demos, and sample bases to jetty-home).
http://search.maven.org/#search|gav|1|g:"org.eclipse.jetty" AND a:"jetty-home"
Unpack that jetty-home artifact into a fresh directory.
Important:
Don't touch any content in jetty-home
Don't edit anything in jetty-home
Don't remove anything from jetty-home
Don't add anything into jetty-home
Leave jetty-home alone
Treat jetty-home as a read-only directory
All above bullets apply even if using jetty-distribution
Lastly, start jetty per the recommendations in the Jetty Documentation.
> cd \path\to\myjettybase
> java -jar \path\to\jetty-home\start.jar
Note the lack of declared system properties for -Djetty.home and -Djetty.base, this is important!
This will set up the following important directory properties.
jetty.base will be your CWD, or \path\to\myjettybase
jetty.home will be where your start.jar was found, aka \path\to\jetty-home\
user.dir will be your CWD and point to \path\to\myjettybase
What's important, for logging configurations like yours, is the user.dir system property. (aka the current working directory)
The technique you are using where you don't pay attention to the working directory and just attempt to force values into the JVM with system properties is only viable in the simplest of projects and usecases. (your requirements have outgrown that kind of setup)