[#converting-sysvinit-services]
= Converting SysVinit services

Older versions of Fedora use SysVinit scripts to manage services. This section provides some guidelines on how to convert a SysVinit script to a systemd equivalent.

.Prerequisites

* You are logged in as a user with administrator-level permissions.

* You have a custom SysVinit script to convert to a systemd configuration.

.Procedure

. Identify the runlevels in your SysVinit script. This is usually defined with `chkconfig` directive in the commented section at the beginning of the script. For example, the following indicates the service is using runlevels 3, 4, and 5:
+
----
# chkconfig: 235 20 80
----
+
systemd uses targets instead of runlevels. Use the table in <<#converting-sysvinit-services>> to map the runlevels to targets. In this example, runlevels 2, 3, and 5 are all multi-user runlevels, so the systemd service can use the following:
+
----
[Install]
WantedBy=multi-user.target
----
+
If you enable the custom systemd service to start at boot (`systemctl enable foo.service`), systemd loads the service when loading the `multi-user.target` at boot time.

. Identify the dependent services and targets. For example, if the custom service requires network connectivity, specify the `network.target` as a dependency:
+
----
[Unit]
Description=My custom service
Requires=network.target
----

. Identify the command used to start the service in the SysVinit script and convert this to the systemd equivalent. For example, the script might contain a `start` function in the following format:
+
[source,bash]
----
start() {
  echo "Starting My Custom Service..."
  /usr/bin/myservice -D
}
----
+
In this example, the `/usr/bin/myservice` command is the custom service command set to daemonize with the `-D` option. Set the `ExecStart` parameter to use this command:
+
----
[Service]
ExecStart=/usr/bin/myservice -D
----

. Check the SysVinit script to see if the service uses a special command to restart the service. For example, the script might contain a `reboot` function that reloads the service:
+
[source,bash]
----
reboot() {
  echo "Reloading My Custom Service..."
  /usr/bin/myservice reload
}
----
+
In this example, the `/usr/bin/myservice` command is the custom service command and reloads the service using the `reload` subcommand. Set the `ExecReload` parameter to use this command:
+
----
[Service]
ExecReload=/usr/bin/myservice reload
----
+
Alternatively, you can omit `ExecReload` and use the default behavior, which kills the service and starts it again.

. Check the SysVinit script to see if the service uses a special command to stop the service. For example, the script might contain a `stop` function that reloads the service:
+
[source,bash]
----
reboot() {
  echo "Stopping My Custom Service..."
  /usr/bin/myservice shutdown
}
----
+
In this example, the `/usr/bin/myservice` command is the custom service command and stop the service gracefully using the `shutdown` subcommand. Set the `ExecStop` parameter to use this command:
+
----
[Service]
ExecStop=/usr/bin/myservice shutdown
----
+
Alternatively, you can omit `ExecStop` and use the default behavior, which kills the service.

. Review the SysVinit script and identify any additional parameters or functions. Use systemd parameters to replicate any identified SysVinit functions that might be relevant to your service.

.Related Information

* See link:#common-service-parameters[Common service parameters] for more information about the parameters used in this procedure.
