Connect to MySQL from shinyapps.io - shiny

Question

I have a working Shiny App that queries a remote MySQL database via pool that I can run on my local machine.
The MySQL server has whitelisted shinyapps.io IP addresses.
When I deploy it to shinyapps.io, I get this error:
.global
library(shiny)
library(DBI)
library(pool)
library(DT)
pool <- dbPool(
drv = RMySQL::MySQL(),
dbname = "gw_observatory",
host = "sage.metro.ucdavis.edu",
username = "gw_observatory",
password = "password"
)
onStop(function() {
poolClose(pool)
})
.server
shinyServer(function(input, output, session) {
output$data_table <- renderDataTable({
DT::datatable(pool %>% tbl("small_data") %>% collect())
})
.ui
shinyUI(
fluidPage(
mainPanel(DT::dataTableOutput("data_table"))
)
)

Answer 1

UPDATE: It works now. My system admin added a port, and that fixed the issue.
For anyone down the line that is running into this issue, there are the steps I recommend:
make sure your shinyapp works locally
if you get deployment errors on shinyapps.io, make sure:
your database has whitelisted shinyappsio IP addresses
your host is an external, public IP or URL and not an internal one
some institutions have very guarded firewalls. Try adding a port to your database.
I hope this helps someone down the line!
pool <- dbPool(
drv = RMySQL::MySQL(),
dbname = "some_name",
host = "123.45.678.901",
username = "some_username",
password = "password",
port = 1234567
)