My coworker wrote a Dancer psgi application called "Newlands" that makes use of perlbrew. I am trying to get the application to start up on system start using systemd. I have this service file:
[Unit]
Description=Newlands
After=network-online.target
[Service]
Type=forking
User=newlands
WorkingDirectory=/home/newlands/working/newlands
PIDFile=/home/newlands/newlands.pid
ExecStartPre=/bin/bash -c 'env > /tmp/newlands.environment'
ExecStartPre=/bin/mkdir -p /tmp/newlands/newlands/session/
ExecStart=/usr/local/bin/starman --host 127.0.0.1 --listen :5000 --env production --preload-app --workers 12 --daemonize --error-log /var/log/newlands/newlands.error.log --pid /home/newlands/newlands.pid bin/newlandia.psgi
EnvironmentFile=-/tmp/newlands.environment
Restart=always
[Install]
WantedBy=multi-user.target
However, even with the ExecStartPre trick (which I got from http://tech.akom.net/archives/93-Getting-a-systemd-unit-to-read-your-.bashrc-file-for-its-environment.html, modified not use the --login option), none of the perlbrew-related environment variables are getting set properly. So I end up with errors indicating missing libraries not found in @INC, when @INC doesn't contain anything at /home/newlands/.perlbrew/libs/perl-5.20.1@newlands where the libraries actually are.
It seems that the outputted file at /tmp/newlands.environment still differs significantly from the output of "env" when actually logged in as the newlands user. I would like to source /opt/perlbrew/etc/bashrc or something like that, but I understand that's not possible.
Any tips? Thanks!
The solution is not to blindly dump your Bash CLI environment into your systemd environment, the solution is to understand what environment variables you need and set those.
As @ikegami points out, your problem is likely related to the PERL5LIB environment variable. So run your app from the CLI from and dump out the value of $ENV{PERL5LIB} to see what value the app expects, then set that in systemd. You may need to repeat the process with other variables.
The result will be a clearly and precisely defined systemd environment that will run your app in a stable and consistent manner, regardless of how your .bashrc gets modified.