CHECK_FREQUENCY_SECONDS: default value for --check-frequency-seconds param
OPNSENSE_MAIN_HOST: default value for --main-host param
OPNSENSE_BACKUP_HOST: default value for --backup-host param
OPNSENSE_USERNAME: default value for --opnsense-user param
OPNSENSE_PASSWORD: default value for --opnsense-password param
OPNSENSE_INTERFACES: default value for --opnsense-interfaces param