This script sets up multiple, identical test databases that can be used by integration tests that run in parallel.

create_test_databases.sh

#!/bin/bash
#
# This script sets up multiple, identical test databases that can be used by
# integration tests that run in parallel.

set -euo pipefail

# Create one test database named `mollie_test_db_1`. Yes, our parallel test
# suits start counting from 1. Don't ask.
# [...]

# Create a dump of the first database
mysqldump --host=localhost --user=root "mollie_test_db_1" > "/tmp/mollie_test_db_dump.sql"

# Import it into all the other databases. Perform the process in the background
# (with the `&` at the end) so all the imports will happen async. Store the PIDs
# so we can later wait for these processes to be completed.
pids_to_wait_for=()

for i in $(seq 2 "${nr_of_databases}"); do
  mysql --host=localhost --user=root "mollie_test_db_${i}" < "/tmp/mollie_test_db_dump.sql" &
  pids_to_wait_for[${i}]=$!
done

# Wait for the MySQL imports to be completed.
for pid in ${pids_to_wait_for[*]}; do
  wait $pid
done

echo "Done!"