Systemd Services
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You can look at existing services for inspiration.
root@QBIT0718:~# systemctl cat sshd.service # /lib/systemd/system/ssh.service [Unit] Description=OpenBSD Secure Shell server Documentation=man:sshd(8) man:sshd_config(5) After=network.target auditd.service ConditionPathExists=!/etc/ssh/sshd_not_to_be_run [Service] EnvironmentFile=-/etc/default/ssh ExecStartPre=/usr/sbin/sshd -t ExecStart=/usr/sbin/sshd -D $SSHD_OPTS ExecReload=/usr/sbin/sshd -t ExecReload=/bin/kill -HUP $MAINPID KillMode=process Restart=on-failure RestartPreventExitStatus=255 Type=notify RuntimeDirectory=sshd RuntimeDirectoryMode=0755 [Install] WantedBy=multi-user.target Alias=sshd.servicePlease also look at the manpage of systemd for more details and options on service configuration.
Services can be created in "/etc/systemd/system/"
root@QBIT0718:~# ls /etc/systemd/system/ cross-seed.service getty.target.wants qbittorrent-nox.service sshd.service cross-seed.service.save multi-user.target.wants remote-fs.target.wants sysinit.target.wants dbus-org.freedesktop.timesync1.service network-online.target.wants sockets.target.wants timers.target.wantsBasic Systemctl Commands:
systemctl enable sshd.service systemctl start sshd.service systemctl disable sshd.service systemctl stop sshd.service systemctl restart sshd.service systemctl reload sshd.service #reload is not as harsh as restart systemctl daemon-reload #reloads systemd, its needed after adding a service for exampleTo View all services on the system if running or not use below command:
systemctl list-units --type service --allExample Output:
root@QBIT0718:~# systemctl list-units --type service --all UNIT LOAD ACTIVE SUB DESCRIPTION apparmor.service loaded active exited Load AppArmor profiles apt-daily-upgrade.service loaded inactive dead Daily apt upgrade and clean activities apt-daily.service loaded inactive dead Daily apt download activities ● auditd.service not-found inactive dead auditd.service auth-rpcgss-module.service loaded inactive dead Kernel Module supporting RPCSEC_GSS ● connman.service not-found inactive dead connman.service ● console-screen.service not-found inactive dead console-screen.service console-setup.service loaded active exited Set console font and keymap cron.service loaded active running Regular background program processing daemon cross-seed.service loaded active running cross-seed daemon dbus.service loaded active running D-Bus System Message Bus ● display-manager.service not-found inactive dead display-manager.service dpkg-db-backup.service loaded inactive dead Daily dpkg database backup service e2scrub_all.service loaded inactive dead Online ext4 Metadata Check for All Filesystems e2scrub_reap.service loaded inactive dead Remove Stale Online ext4 Metadata Check Snapshots emergency.service loaded inactive dead Emergency Shell fstrim.service loaded inactive dead Discard unused blocks on filesystems from /etc/fstab getty-static.service loaded inactive dead getty on tty2-tty6 if dbus and logind are not available getty@tty1.service loaded active running Getty on tty1 ● gssproxy.service not-found inactive dead gssproxy.service ifup@ens18.service loaded active exited ifup for ens18 ifupdown-pre.service loaded active exited Helper to synchronize boot up for ifupdown initrd-cleanup.service loaded inactive dead Cleaning Up and Shutting Down Daemons initrd-parse-etc.service loaded inactive dead Mountpoints Configured in the Real Root initrd-switch-root.service loaded inactive dead Switch Root initrd-udevadm-cleanup-db.service loaded inactive dead Cleanup udev Database ● kbd.service not-found inactive dead kbd.service keyboard-setup.service loaded active exited Set the console keyboard layout kmod-static-nodes.service loaded active exited Create List of Static Device Nodes logrotate.service loaded inactive dead Rotate log files man-db.service loaded inactive dead Daily man-db regeneration modprobe@configfs.service loaded inactive dead Load Kernel Module configfs modprobe@dm_mod.service loaded inactive dead Load Kernel Module dm_mod modprobe@drm.service loaded inactive dead Load Kernel Module drm modprobe@efi_pstore.service loaded inactive dead Load Kernel Module efi_pstore modprobe@fuse.service loaded inactive dead Load Kernel Module fuse modprobe@loop.service loaded inactive dead Load Kernel Module loop networking.service loaded active exited Raise network interfaces ● NetworkManager.service not-found inactive dead NetworkManager.service ● nfs-server.service not-found inactive dead nfs-server.service nfs-utils.service loaded inactive dead NFS server and client services ● plymouth-quit-wait.service not-found inactive dead plymouth-quit-wait.service ● plymouth-start.service not-found inactive dead plymouth-start.service qbittorrent-nox.service loaded active running qBittorrent Command Line Client rc-local.service loaded inactive dead /etc/rc.local Compatibility rescue.service loaded inactive dead Rescue Shell rpc-gssd.service loaded inactive dead RPC security service for NFS client and server rpc-statd-notify.service loaded active exited Notify NFS peers of a restart rpc-statd.service loaded active running NFS status monitor for NFSv2/3 locking. rpc-svcgssd.service loaded inactive dead RPC security service for NFS server rpcbind.service loaded active running RPC bind portmap service snmpd.service loaded active running Simple Network Management Protocol (SNMP) Daemon. ssh.service loaded active running OpenBSD Secure Shell server ● syslog.service not-found inactive dead syslog.service systemd-ask-password-console.service loaded inactive dead Dispatch Password Requests to Console systemd-ask-password-wall.service loaded inactive dead Forward Password Requests to Wall systemd-binfmt.service loaded active exited Set Up Additional Binary Formats systemd-firstboot.service loaded inactive dead First Boot Wizard systemd-fsck-root.service loaded inactive dead File System Check on Root Device systemd-fsckd.service loaded inactive dead File System Check Daemon to report status ● systemd-hwdb-update.service not-found inactive dead systemd-hwdb-update.service systemd-initctl.service loaded inactive dead initctl Compatibility Daemon systemd-journal-flush.service loaded active exited Flush Journal to Persistent Storage systemd-journald.service loaded active running Journal Service systemd-logind.service loaded active running User Login Management systemd-machine-id-commit.service loaded inactive dead Commit a transient machine-id on disk systemd-modules-load.service loaded active exited Load Kernel Modules systemd-networkd.service loaded inactive dead Network Configuration ● systemd-oomd.service not-found inactive dead systemd-oomd.service systemd-pcrphase-initrd.service loaded inactive dead TPM2 PCR Barrier (initrd) systemd-pcrphase-sysinit.service loaded inactive dead TPM2 PCR Barrier (Initialization) systemd-pcrphase.service loaded inactive dead TPM2 PCR Barrier (User) systemd-pstore.service loaded inactive dead Platform Persistent Storage Archival systemd-random-seed.service loaded active exited Load/Save Random Seed systemd-remount-fs.service loaded active exited Remount Root and Kernel File Systems systemd-repart.service loaded inactive dead Repartition Root Disk systemd-sysctl.service loaded active exited Apply Kernel Variables systemd-sysext.service loaded inactive dead Merge System Extension Images into /usr/ and /opt/ systemd-sysusers.service loaded active exited Create System Users systemd-timesyncd.service loaded active running Network Time Synchronization systemd-tmpfiles-clean.service loaded inactive dead Cleanup of Temporary Directories systemd-tmpfiles-setup-dev.service loaded active exited Create Static Device Nodes in /dev systemd-tmpfiles-setup.service loaded active exited Create System Files and Directories systemd-udev-settle.service loaded inactive dead Wait for udev To Complete Device Initialization systemd-udev-trigger.service loaded active exited Coldplug All udev Devices systemd-udevd.service loaded active running Rule-based Manager for Device Events and Files ● systemd-update-done.service not-found inactive dead systemd-update-done.service systemd-update-utmp-runlevel.service loaded inactive dead Record Runlevel Change in UTMP systemd-update-utmp.service loaded active exited Record System Boot/Shutdown in UTMP systemd-user-sessions.service loaded active exited Permit User Sessions ● systemd-vconsole-setup.service not-found inactive dead systemd-vconsole-setup.service user-runtime-dir@0.service loaded active exited User Runtime Directory /run/user/0 user@0.service loaded active running User Manager for UID 0 wazuh-agent.service loaded active running Wazuh agent wg-quick@wg0.service loaded active exited WireGuard via wg-quick(8) for wg0 LOAD = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB = The low-level unit activation state, values depend on unit type. 95 loaded units listed. To show all installed unit files use 'systemctl list-unit-files'.
