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[update] Use systemd to Start a Linux Service at Boot (#7221)
* [update] Use systemd to Start a Linux Service at Boot Incorporated the review comments * Update index.md formatting changes * fix blueberry * copy edits and update code block formatting --------- Co-authored-by: jddocs <[email protected]>
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‎docs/guides/quick-answers/linux/start-service-at-boot/index.md

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@@ -5,6 +5,7 @@ description: The systemd daemon allows you to control Linux system services. Thi
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authors: ["Linode"]
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contributors: ["Linode"]
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published: 2018-05-01
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modified: 2025-03-27
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keywords: ["systemd","service","enable service","Linux system service"]
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license: '[CC BY-ND 4.0](https://creativecommons.org/licenses/by-nd/4.0)'
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external_resources:
@@ -25,118 +26,141 @@ It is simple to create a custom systemd service that will run any script or proc
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1. Create a script or executable that the service will manage. This guide uses a simple Bash script as an example:
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{{< file "test_service.sh" bash >}}
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DATE=`date '+%Y-%m-%d %H:%M:%S'`
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echo "Example service started at ${DATE}" | systemd-cat -p info
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```file {title="test_service.sh" lang="bash"}
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DATE=`date '+%Y-%m-%d %H:%M:%S'`
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echo "Example service started at ${DATE}" | systemd-cat -p info
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while :
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do
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echo "Looping...";
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sleep 30;
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done
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{{< /file >}}
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while :
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do
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echo "Looping...";
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sleep 30;
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done
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```
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This script will log the time at which it is initialized, then loop infinitely to keep the service running.
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2. Copy the script to `/usr/bin` and make it executable:
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sudo cp test_service.sh /usr/bin/test_service.sh
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sudo chmod +x /usr/bin/test_service.sh
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```command
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sudo cp test_service.sh /usr/bin/test_service.sh
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sudo chmod +x /usr/bin/test_service.sh
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```
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3. Create a **Unit file** to define a systemd service:
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3. Create a **Unit file** to define a systemd service in your application, where `/opt/myapp/` is the path to your application directory.
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{{< file "/lib/systemd/system/myservice.service" conf >}}
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[Unit]
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Description=Example systemd service.
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```file {title="/opt/myapp/myservice.service"}
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[Unit]
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Description=Example systemd service.
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[Service]
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Type=simple
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ExecStart=/bin/bash /usr/bin/test_service.sh
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[Service]
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Type=simple
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ExecStart=/bin/bash /usr/bin/test_service.sh
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[Install]
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WantedBy=multi-user.target
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{{< /file >}}
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[Install]
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WantedBy=multi-user.target
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```
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This defines a simple service. The critical part is the `ExecStart` directive, which specifies the command that will be run to start the service.
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* This defines a simple service that runs `/usr/bin/test_service.sh` through Bash.
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* The `ExecStart` directive specifies the command to run.
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* The `[Install]` section allows the service to be enabled at boot.
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4. Copy the unit file to `/etc/systemd/system` and give it permissions:
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4. Link the unit file from your application directory. This approach can streamline deployments by keeping the service definition with your codebase:
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sudo cp myservice.service /etc/systemd/system/myservice.service
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sudo chmod 644 /etc/systemd/system/myservice.service
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```command
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sudo systemctl enable /opt/myapp/myservice.service
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```
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If the `[Install]` section is present, this creates the necessary symlinks in `/etc/systemd/system/`.
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Alternatively, copy the unit file to `/etc/systemd/system/`, and adjust the permissions:
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```command
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sudo cp myservice.service /etc/systemd/system/myservice.service
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sudo chmod 644 /etc/systemd/system/myservice.service
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```
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For more information about the unit file and its available configuration options, see the [systemd documentation](https://www.freedesktop.org/wiki/Software/systemd/).
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## Start and Enable the Service
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1. Once you have a unit file, you are ready to test the service:
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sudo systemctl start myservice
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```command
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sudo systemctl start myservice
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```
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2. Check the status of the service:
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sudo systemctl status myservice
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```command
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sudo systemctl status myservice
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```
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If the service is running correctly, the output should resemble the following:
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{{< output >}}
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● myservice.service - Example systemd service.
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Loaded: loaded (/lib/systemd/system/myservice.service; enabled; vendor preset: enabled)
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Active: active (running) since Tue 2018-05-01 18:17:14 UTC; 4s ago
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Main PID: 16266 (bash)
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Tasks: 2
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Memory: 748.0K
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CPU: 4ms
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CGroup: /system.slice/myservice.service
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├─16266 /bin/bash /usr/bin/test_service.sh
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└─16270 sleep 30
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May 01 18:17:14 localhost systemd[1]: Started Example systemd service..
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May 01 18:17:14 localhost cat[16269]: Example service started at 2018-05-01 18:17:14
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May 01 18:17:14 localhost bash[16266]: Looping...
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{{< /output >}}
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```output
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● myservice.service - Example systemd service.
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Loaded: loaded (/lib/systemd/system/myservice.service; enabled; vendor preset: enabled)
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Active: active (running) since Tue 2018-05-01 18:17:14 UTC; 4s ago
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Main PID: 16266 (bash)
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Tasks: 2
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Memory: 748.0K
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CPU: 4ms
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CGroup: /system.slice/myservice.service
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├─16266 /bin/bash /usr/bin/test_service.sh
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└─16270 sleep 30
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May 01 18:17:14 localhost systemd[1]: Started Example systemd service..
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May 01 18:17:14 localhost cat[16269]: Example service started at 2018-05-01 18:17:14
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May 01 18:17:14 localhost bash[16266]: Looping...
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```
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3. The service can be stopped or restarted using standard systemd commands:
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sudo systemctl stop myservice
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sudo systemctl restart myservice
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```command
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sudo systemctl stop myservice
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sudo systemctl restart myservice
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```
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4. Finally, use the `enable` command to ensure that the service starts whenever the system boots:
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sudo systemctl enable myservice
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```command
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sudo systemctl enable myservice
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```
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{{< output >}}
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Created symlink from /etc/systemd/system/multi-user.target.wants/myservice.service to /lib/systemd/system/myservice.service.
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{{< /output >}}
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```output
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Created symlink from /etc/systemd/system/multi-user.target.wants/myservice.service to /lib/systemd/system/myservice.service.
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```
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5. Reboot your Linode from the Linode Manager and check the status of the service:
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sudo systemctl status myservice
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```command
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sudo systemctl status myservice
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```
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You should see that the service logged its start time immediately after booting:
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{{< output >}}
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● myservice.service - Example systemd service.
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Loaded: loaded (/usr/lib/systemd/system/myservice.service; enabled; vendor preset: disabled)
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Active: active (running) since Wed 2018-05-02 15:03:07 UTC; 48s ago
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Main PID: 2973 (bash)
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CGroup: /system.slice/myservice.service
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├─2973 /bin/bash /usr/bin/test_service.sh
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└─3371 sleep 30
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May 02 15:03:07 localhost systemd[1]: Started Example systemd service..
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May 02 15:03:07 localhost systemd[1]: Starting Example systemd service....
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May 02 15:03:07 localhost bash[2973]: Looping...
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May 02 15:03:37 localhost bash[2973]: Looping...
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{{< /output >}}
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```output
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● myservice.service - Example systemd service.
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Loaded: loaded (/usr/lib/systemd/system/myservice.service; enabled; vendor preset: disabled)
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Active: active (running) since Wed 2018-05-02 15:03:07 UTC; 48s ago
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Main PID: 2973 (bash)
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CGroup: /system.slice/myservice.service
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├─2973 /bin/bash /usr/bin/test_service.sh
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└─3371 sleep 30
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For more information about using `systemctl` commands, see the [systemctl guide](/docs/guides/introduction-to-systemctl).
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May 02 15:03:07 localhost systemd[1]: Started Example systemd service..
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May 02 15:03:07 localhost systemd[1]: Starting Example systemd service....
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May 02 15:03:07 localhost bash[2973]: Looping...
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May 02 15:03:37 localhost bash[2973]: Looping...
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```
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For more information about using `systemctl` commands, see the [systemctl guide](/docs/guides/introduction-to-systemctl).
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## Troubleshooting
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- "Example service started at ..." line does not appear in the output of the status command. The `systemd-cat` output is not reliable because of a race condition. As a workaround update the `test_service.sh` file as follows:
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{{< file "test_service.sh" bash >}}
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If the `Example service started at ...` line does not appear in the output of the status command, the `systemd-cat` output may not be reliable because of a race condition. As a workaround, you can update the `test_service.sh` file as follows:
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```file {title="test_service.sh" lang="bash"}
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info=/tmp/myservice-systemd-cat-pipe-info
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mkfifo "$info"
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trap "exec 3>&-; rm $info" EXIT
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echo "Looping...";
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sleep 30;
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done
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{{< /file >}}
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```

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