related slapos MR: slapos!2006 (merged)
after this change, below is the command used by test node to launch test
runUnitTest --verbose '--erp5_sql_connection_string=erp5_test_0@10.0.153.72:2099 testuser_0 testpassword0' --erp5_catalog_storage=erp5_mysql_innodb_catalog --xvfb_bin=/srv/slapgrid/slappart17/srv/slapos/soft/4f8f5629257b20e739faf7921e7832df/parts/xserver/bin/Xvfb --firefox_bin=/srv/slapgrid/slappart17/srv/slapos/soft/4f8f5629257b20e739faf7921e7832df/bin/firefox '--extra_sql_connection_string_list=erp5_test_1@10.0.153.72:2099 testuser_1 testpassword1,erp5_test_2@10.0.153.72:2099 testuser_2 testpassword2' --zserver=10.0.153.72:2201 --zserver_frontend_url=https://10.0.153.72:2150/unit_test_0/ --bt5_path=None --log_directory /srv/slapgrid/slappart17/var/log/testnode/exf-DUEfyWpaYI/erp5_big_file_testBigFile --instance_home unit_test.1 erp5_big_file:testBigFile```