Systemd ignores After and Requires for my service

Question

I've created a service that runs a Bluetooth server application and is started like this:

[Unit]
After=bluetooth.service
Requires=bluetooth.service

[Service]
Type=simple
ExecStartPre=/usr/bin/sdptool add SP
ExecStartPre=/bin/sleep 0.5
ExecStartPre=/bin/hciconfig hci0 piscan
ExecStart=/usr/local/bin/my-service.py
ExecStartPost=/usr/bin/bluetoothctl discoverable on
Restart=always
RestartSec=15

[Install]
WantedBy=multi-user.target

When I look at the logs for this unit after a system boot, I always see the first start failed and the second succeeds. When looking at the full log, I see that my service is started first, then fails, and later only the bluetooth service is started. My service is retried after that and then the required dependencies are there.

Why does Systemd ignore the After and Requires options in my service?

I've read other web texts, man pages and questions here that suggest using exactly these options for my task. But it's not working for me.

The device is a Raspberry Pi 3B+ with Raspbian OS, Linux kernel 5.4.51 and Systemd 241.

Answer 1

Seems to be some quirks with the bluetooth.service from bluez (see this issue). I don't fully understand the reasons behind it. But changing the service WantedBy from multi-user.target to bluetooth.target has fixed it for me.

[Install]
WantedBy=bluetooth.target