Lock screen after suspend with i3lock and systemd

wakelock.service

# file /etc/systemd/system/wakelock.service

[Unit]
Description=Lock the screen on resume from suspend
Before=sleep.target suspend.target

[Service]
User=%i
Type=forking
Environment=DISPLAY=":1"
ExecStart=/usr/bin/i3lock --color='#111111'

[Install]
WantedBy=sleep.target suspend.target

# Note that my DISPLAY is set to :1. You can verifiy what display you're using with `echo $DISPLAY`.
# You can of course change _ExecStart_ to whatever lock service you prefer.

# Save the file, then enable and reload systemd:
# `sudo systemctl enable wakelock@$(whoami).service && sudo systemctl daemon-reload`

# Verify that the service is loaded (it won't become active until you suspend):
# `systemctl status wakelock@$(whoami).service`

# Reference: [Lock screen after suspend with i3lock and systemd](https://gist.github.com/victorhaggqvist/603125bbc0f61a787d89)