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--- linux_wiki:systemd_service_script [2016/01/31 22:37]
billdozor [Implementation]
+++ linux_wiki:systemd_service_script [2019/05/25 23:50]
@@ Line 1: / Line 1: @@
-====== Systemd Service Script ======
-**General Information**
-Creating a systemd until file (service script).
-**Checklist**
-  * Enterprise Linux 7
-----
-====== Unit File Reference ======
-  * /usr/lib/systemd/system => system unit configuration files (default with system)
-  * /etc/systemd/system => additional configuration files (downloaded or custom)
-----
-====== Implementation ======
-  * Download the code
-  * Modify each section to make sense for your service
-  * Copy to /etc/systemd/system/<name-of-service>.service
-  * Start your service<code bash>systemctl start <name-of-service></code>
-    * **Note: This will fail if the ExecStart script/program does not have the executable permissions or if the Environment config file does not exist.**
-----
-====== The Service Unit File ======
-<code bash myprog.service>
-[Unit]
-Description=My Awesome Program
-After=syslog.target
-[Service]
-EnvironmentFile=/etc/myprog.d/config
-ExecStart=/usr/local/bin/myprog.sh
-Restart=on-abort
-[Install]
-WantedBy=multi-user.target
-</code>
-  * Description => Displays near the top of output on "systemctl status myprog.service"
-  * After => can be any valid ".target" unit
-    * See all: systemctl -t target --all
-  * EnvironmentFile => Configuration file to load
-  * ExecStart => Executable to start
-  * Restart => Auto restarts the program if an un-handled exit error occurs
-  * WantedBy => If enabled, start under which target
-----
-===== Example: Test Script =====
-This is the script that was used to test the custom systemd service unit file.
-/usr/local/bin/myprog.sh
-<code bash>
-#!/bin/bash
-echo "Welcome to my program"
-logger -p info "$0 has started on $(date)"
-while true; do
-  logger -p info "$0 is still running..."
-  sleep 30
-done
-</code>
-  * **Note: Ensure this script is executable, or the service will fail to start.**
-----
-==== Example: Service Status ====
-<code bash>
-[root@server1 system]# systemctl start myprog.service
-[root@server1 system]# systemctl status myprog.service
-● myprog.service - My Awesome Program
-   Loaded: loaded (/etc/systemd/system/myprog.service; disabled; vendor preset: disabled)
-   Active: active (running) since Sun 2016-01-24 10:30:08 CST; 6s ago
- Main PID: 17602 (myprog.sh)
-   CGroup: /system.slice/myprog.service
-           ├─17602 /bin/bash /usr/local/bin/myprog.sh
-           └─17608 sleep 30
-Jan 24 10:30:08 server1.local systemd[1]: Started My Awesome Program.
-Jan 24 10:30:08 server1.local systemd[1]: Starting My Awesome Program...
-Jan 24 10:30:08 server1.local myprog.sh[17602]: Welcome to my program
-</code>
-----
-==== Example: Logs ====
-<code bash>
-journalctl -f
--- Logs begin at Fri 2015-12-25 22:36:05 CST. --
-Jan 24 10:30:08 server1.local systemd[1]: Starting My Awesome Program...
-Jan 24 10:30:08 server1.local myprog.sh[17602]: Welcome to my program
-Jan 24 10:30:08 server1.local logger[17605]: /usr/local/bin/myprog.sh has started on Sun Jan 24 10:30:08 CST 2016
-Jan 24 10:30:08 server1.local logger[17606]: /usr/local/bin/myprog.sh is still running...
-Jan 24 10:30:38 server1.local logger[17683]: /usr/local/bin/myprog.sh is still running...
-Jan 24 10:31:08 server1.local logger[17693]: /usr/local/bin/myprog.sh is still running...
-</code>
-----