Do I need to open remote MySQL on my server to all IP addresses if connecting to a shinyapp.io app?

[andresrcs]

No, not necessarily. Here you can find the IPs you need to white list.

New IP addresses as of 8/10/2019

Sometime after 8/10/2019 we will begin using the following additional IP address: 34.203.76.245 3.217.214.132 34.197.152.155 in addition to the existing IP addresses: 54.204.34.9 54.204.36.75 54.204.37.78 If your shinyapps.io accesses resources behind a firewall, you will need to ensure you or your IT department updates the list of IP addresses prior to that date.