Connect to Postgres via SSL using R

https://github.com/r-dbi/RPostgres seems to be the more modern and maintained package at this point. This is what worked for me...

install.packages("RPostgres")
require(RPostgres)

db = dbConnect(
  Postgres(), 
  user = 'user',
  password = 'password',
  dbname = 'dbname',
  host = 'host',
  port = port,
  sslmode = 'require'
)

dbListTables(db)

Instead of passing verify-full to sslmode, try require or allow:

dbConnect(dbDriver('PostgreSQL'),
    dbname   = 'dbname=foobar sslmode=require',
    host     = 'foobar.redshift.amazonaws.com',
    port     = 5439,
    user     = 'foobar',
    password = 'foobar')

This worked for me:

connection <- DBI::dbConnect(RPostgres::Postgres(),
                             dbname = "dbname",
                             host = "host",
                             port = "port",
                             password = "password",
                             user = "user_name",
                             base::list(sslmode="require", connect_timeout="10"),
                             service = NULL)

So the parameter key words can be passed as a list. This worked for RPostgres 1.1.1 and 1.2.0, as well.