Consider yoyo migrations as an alternative to Flyway.  Allows for the migrations to be written in either SQL or Python, is oth open source and much easier to integrate. https://pypi.org/project/yoyo-migrations/ 

Amiram,

Most higher end firewalls (Palo Alto, Cisco ASA, et al) will support whitelisting FQDNs.  In setting this up, be careful in your choice of DNS providers to preclude spoofing.  It may take some careful education and testing to get this accepted by your customer's network security team, but this is increasingly common practice with more and more web services being cloud-based and delivered with HA and DR across multiple data centers each having multiple numeric address ranges.

Cheers,

- Evan