Here is the working script I use to restore prod to dev and test:
#!/bin/sh
set +x
set -e
# This script restore the latest productive backup to the test/dev environment
CONTAINER_NAME=app-test
LATEST_BACKUP=$(mc ls s3/backup-prod/default | tail -n 1 | cut -d ' ' -f 5)
mc cp s3/backup-prod/default/${LATEST_BACKUP} /tmp
# ensure /var/www/discourse/public/backups/default/ exists with the proper ownership
docker exec -i ${CONTAINER_NAME} sh -c "mkdir -p /var/www/discourse/public/backups/default/ && chown -R discourse:www-data /var/www/discourse/public/backups/default/"
cat /tmp/${LATEST_BACKUP} | docker exec -i ${CONTAINER_NAME} sh -c "cat - > /var/www/discourse/public/backups/default/${LATEST_BACKUP}"
docker exec -i ${CONTAINER_NAME} sh -x << EOF
discourse enable_restore
rails runner "SiteSetting.set('backup_location', 'local')"
discourse restore ${LATEST_BACKUP}
discourse disable_restore
rm -f /var/www/discourse/public/backups/default/${LATEST_BACKUP}
EOF
# rebuild container
cd /var/lib/discourse/discourse_docker
stdbuf -oL -eL ./launcher rebuild ${CONTAINER_NAME} 2>&1 | sed 's/DISCOURSE_google_oauth2_client_secret=[^ ]*/DISCOURSE_google_oauth2_client_secret=***REDACTED***/g'
cd -
rm -f /tmp/${LATEST_BACKUP}
The rails runner "SiteSetting.set('backup_location', 'local')" was missing and preventing restore from the backup tarball.
Note that the output of the launcher script had to be redacted as it would disclose secrets in it’s output especially when done over a visible CI/CD job.