在 AWS EC2 中将 Rstudio 与 PostgreSQL 连接

Question

I am currently running PostgreSQL server in AWS EC2 (Ubuntu) and having trouble accessing it from local server. How can I access remote database from local RStudio?

Code in R:

library(RPostgreSQL)
library(DBI)

drv <- dbDriver("PostgreSQL")

con <- dbConnect(drv, user='postgres', password='password', dbname='dvd', host='ec2-xx-xxx-xxxx-xxxx.ap-northeast-2.compute.amazonaws.com',port=5432)

dbListTables(con)

Result:

Error in postgresqlNewConnection(drv, ...) : 
  RS-DBI driver: (could not connect postgres@ec2-xx-xxx-xxxx-xxxx.ap-northeast-2.compute.amazonaws.com:5432 on dbname "dvd": FATAL:  no pg_hba.conf entry for host "130.17.152.1”, user "postgres", database "dvd", SSL off
)
Calls: <Anonymous> ... eval -> dbConnect -> dbConnect -> postgresqlNewConnection
Execution halted

For AWS security group, I have added an inbound for PostgreSQL with its source set it to anywhere with port range 5432.

Answer 1

By default Postgres does not allow remote connections. To allow remote connections you will need to add an entry to the pg_hba.conf file on the EC2 server. The exact location of pg_hba.conf varies with different installations, but here are some paths to try:

/etc/postgresql/[VERSION]/main/
/var/lib/postgresql/[version]/

Once you've found your pg_hba.conf you need to add a line to allow remote connections, for example.

# TYPE  DATABASE        USER            ADDRESS                 METHOD
  host  dvd             postgres        130.17.152.1/32         md5

This assumes that your local server IP (130.17.152.1) is static. If not, you could use 0.0.0.0/0 for ADDRESS, also, you can use all for DATABASE and USER like so:

# TYPE  DATABASE        USER            ADDRESS                 METHOD
  host  all             all             0.0.0.0:0                     md5

Depends how tight you want your security to be, but bear in mind this is security at the database level and is completely separate to your AWS security groups.

See https://www.postgresql.org/docs/9.1/auth-pg-hba-conf.html for more information.