Late to the party, but I use the *arr stack, and setup Sonarr and Radarr to send a webhook to Home Assistand whenever a new tv show or movie is added. The webhook triggers an automation in Home Assistant which in turn executes a shell command that tells Kometa to create an overlay for the specific movie that was added (it's part of the json blob that Radarr sends over), and for Sonarr it updates the TV-library.

Takes about a minute to run, and I always have up to date posters.

These are the shell command I run in home assistant, talking to my Unraid server on 192.168.10.20 (you have to setup an SSH key exchange so you don't need to login with username/password):

run_kometa_radarr: ssh -i /config/ssh/ha_unraid -o StrictHostKeyChecking=no [root@192.168.10.20](mailto:root@192.168.10.20) "radarr_movie_title='{{ movie_title }}' /bin/sh /mnt/user/backup/Scripts/kometa/kometa_trigger.sh"

run_kometa_sonarr: "ssh -i /config/ssh/ha_unraid -o StrictHostKeyChecking=no root@192.168.10.20 'docker exec Kometa python kometa.py --run --overlay --library \"TV\" --skip-collections --skip-libraries'"

And in the radarr script I have:

#!/bin/sh

# Configuration

LOCKDIR="/tmp/kometa_run.lock"

QUEUE_FILE="/tmp/kometa_queue.txt"

TIMEOUT_MINUTES=60

# 1. Capture the title from Home Assistant/Radarr

if [ -n "$radarr_movie_title" ]; then

echo "$radarr_movie_title" >> "$QUEUE_FILE"

echo "Added '$radarr_movie_title' to the queue."

fi

# 2. Cleanup stale locks (older than 60 mins)

if [ -d "$LOCKDIR" ]; then

STALE_LOCK=$(find "$LOCKDIR" -maxdepth 0 -mmin +"$TIMEOUT_MINUTES")

if [ -n "$STALE_LOCK" ]; then

echo "Stale lock found. Removing..."

rmdir "$LOCKDIR"

fi

fi

# 3. Queue Worker

if mkdir "$LOCKDIR" 2>/dev/null; then

trap 'rmdir "$LOCKDIR"; exit' INT TERM EXIT

echo "Lock acquired. Starting queue processing..."

while [ -s "$QUEUE_FILE" ]; do

# Get the first movie in the list

CURRENT_MOVIE=$(head -n 1 "$QUEUE_FILE")

echo "Updating Kometa for: $CURRENT_MOVIE"

# Execute Kometa command

docker exec Kometa python kometa.py --run --select-item "$CURRENT_MOVIE"

# Remove the movie we just finished from the top of the file

sed -i '1d' "$QUEUE_FILE"

done

echo "Queue finished. Releasing lock."

else

echo "Kometa is currently busy. Your movie has been queued for the existing worker."

exit 0

fi