As pointed out by @danbst, the tomcat NixOS module expects packages
listed in services.tomcat.webapps to either be direct .war file paths or
have .war files inside a "webapps" directory.
Commit 4075c10a59
("jenkins: move .war file from $out to $out/lib/jenkins.war") broke
jenkins + tomcat. Fix it by moving jenkins.war to $out/webapps/.
Fixes #14137, also known as:
$ nix-shell -p jenkins
bash: source: /nix/store/ln1yw6c2v8bb2cjqfr1z5aqcssw054wa-jenkins-2.3:
cannot execute binary file
[nix-shell exited with error]
The problem is that jenkins.war is not installed inside the directory
$out, but rather _as the file_ $out. Fix it by moving the file to
$out/lib/jenkins.war.
While at it, move buildCommand so that the "meta" section is at the end
of the expression (standard style), and quote shell variables.
By default the jenkins server is executed under the user "jenkins". Which can be configured using
users.jenkins.* options. If a different user is requested by changing services.jenkins.user then
none of the users.jenkins options apply.
This patch does not include jenkins slave configuration. Some config options will probably change
when this is implemented.
Aspects like the user and environment are typically identical between slave and master. The service
configs are different. The design is for users.jenkins to cover the shared aspects while
services.jenkins and services.jenkins-slave cover the master and slave specific aspects,
respectively.
Another option would be to place everything under services.jenkins and have a config that selects
master vs slave.
