A systemd WTF - NFHN Reader

This one is my personal WTF, which might just be my basic misunderstanding of the topic.

Running a web application on a far too old Debian, I am trying to upgrade the distribution to the latest stable version — I have postponed this for far too long fearing the systemd.

So I wrote a unit file: /etc/systemd/system/web.service.

Unit]
Description=web.service Service]
WorkingDirectory=/opt/web
ExecStart=/opt/bin/web -c /opt/web/config

Linked it into the /etc/systemd/system/multi-user.target.wants, and tried to start it:

# systemctl start web.service
# systemctl status web.service
[…]
’/opt/web/config’: No such file or directory

The web service needs a config directory in /opt/web/config, or it won’t start. So I decided to add it.

Unit]
Description=web.service Service]
WorkingDirectory=/opt/web
ExecStartPre=mkdir -p /opt/web/config
ExecStart=/opt/bin/web -c /opt/web/config

Running systemctl restart web.service results in Warning: web.service changed on disk. Run ‘systemctl daemon-reload’ to reload units.

OK then, systemctl daemon-reload it is.

Trying to see if it worked again:

# systemctl restart web.service
# systemctl status web.service
[…]
 Active: inactive (dead) since Thu 2016–12–29 16:10:15 UTC; 5s ago
[…]
’/opt/web/config’: No such file or directory

Right. Investigating.

Trying /opt/bin/web -c /opt/web/config by hand.
Result: ’/opt/web/config’: No such file or directory
# ls -la /opt/web/config ls: cannot access ‘/opt/web/config’: No such file or directory

WTF?

There are no warning with daemon-reload or restart, See anything wrong with the Unit file? Turns out, there was an error on daemon-reload. But systemd decided to ignore it and let me start web.service as if nothing happened.

# journalctl | grep web.service
Dec 29 16:07:25 systemd[1]: [/etc/systemd/system/web.service:6] Executable path is not absolute, ignoring: mkdir -p /opt/web/config

I can easily imagine other applications depending on ExecStartPre and failing in completely unexpected ways during run time.

This is not the first problem I have encountered, but it was trivial enough to understand and write about. It seems that the “UI” choices the systemd developers made, are not so consistent.

I wonder why are simple things so difficult here. Is there an error in my thinking? Do I use the tool in entirely different way as it was indended to be used?

I really wish to see it developing towards “There is obviously nothing wrong” with systemd as opposed to the current situation.

Edit: fixed formatting of the code parts.

Edit 2: Apparently the solution would be to run
systemctl edit web.service && systemd-analyze verify web.service
I wonder if systectl daemon-reload could just spit out the warnings and errors by default and would not implicitly defer it to journalctl