/var/log and journalctl are very important to check system well being.
The problem is, you need root privilege.
user$ less /var/log/syslog
/var/log/syslog: Permission denied
Rev2
Add warning section about sudo.
Read /var/log files from a normal user
Debian provides various system groups, and adm is what we want in this case.
It allows a user to read under /var/log.
root# adduser USER adm
Attention!
You should reboot the system.
user$ groups
user adm cdrom floppy audio dip video plugdev netdev
user$ less /var/log/syslog
...(log can be readable now)
journalctl case
So is systemd-journal system group.
No sudo for log monitoring
Avoid using sudo especially with the initial sudo group just to look syslogs.
As shown above, we do NOT need sudo for log monitoring.