Connect to remote postgresql server on amazon ec2

Question

I started an amazon ec2 instance, and installed postgresql 9.1 over it. I then went to the Security Group: quicklaunch-1(there was one moredefault` which i did not change) and opened the 5432 TCP Port, the table looks like this:

(Service)   Source  Action
22        0.0.0.0/0         Delete
5432      0.0.0.0/32    Delete
5433      0.0.0.0/32    Delete
6432      0.0.0.0/32    Delete

I have created a database and user . My /etc/postgresql/9.1/main/pg_hba.conf looks like this:

# Database administrative login by Unix domain socket
local   all             postgres                                peer

# TYPE  DATABASE        USER            ADDRESS                 METHOD
host    all             all             0.0.0.0/0               md5
host    db_name         user_name       0.0.0.0/0               md5

# "local" is for Unix domain socket connections only
local   all             all                                     peer
# IPv4 local connections:
host    all             all             127.0.0.1/32            md5
# IPv6 local connections:
host    all             all             ::1/128                 md5
# Allow replication connections from localhost, by a user with the
# replication privilege.
#local   replication     postgres                                peer
host    replication     postgres        127.0.0.1/32            md5
host    replication     postgres        ::1/128                 md5

and /etc/postgresql/9.1/main/postgresql.conf looks like this:

# - Connection Settings -
listen_addresses = '*'
#listen_addresses = 'localhost'         # what IP address(es) to listen on;
                                        # comma-separated list of addresses;
                                        # defaults to 'localhost', '*' = all
                                        # (change requires restart)
port = 5432                             # (change requires restart)

I then try to connect on to the remote machine as follows:

psql -h ec2-xxx-xx-xxx-xxx.compute-1.amazonaws.com -d <database_name> -U <username>

where ec2-xxx-xx-xxx-xxx.compute-1.amazonaws.com is my Public DNS.

The above command does not result in any connection, how can i connect?

Solution 1

In this table:

5432      0.0.0.0/32    Delete
5433      0.0.0.0/32    Delete
6432      0.0.0.0/32    Delete 

the CIDRs look like you're not allowing any IP in. Shouldn't they be 0.0.0.0/0 instead, like what you have for port 22 (ssh)?

Solution 2

I Found the resolution to this problem. Two things are required.

1. Use a text editor to modify pg_hba.conf. Locate the line host all all 127.0.0.1/0 md5. Immediately below it, add this new line: host all all 0.0.0.0/0 md5

2. Editing the PostgreSQL postgresql.conf file:

   Use a text editor to modify postgresql.conf. Locate the line that starts with #listen_addresses = 'localhost'. Uncomment the line by deleting the #, and change localhost to *. The line should now look like this: listen_addresses = '*' # what IP address(es) to listen on;.

Now Just restart your postgres service and it will connect

Comments

[whatf]

what is the difference between port 32 and port 0.

[Daniel Vérité]

@whatf: 32 is not a port number, it's the prefix size in CIDR notation. 0.0.0.0/0 means allowing connections from any address. 5432 is the port number.

[chhantyal]

You probably need to enable SSL/TLS if you go with this option.

[Kalob Taulien]

If you want to allow all addresses to access your database, don't use listen_addresses = '' on Postgres9.5, use listen_addresses = '*' (note the asterisk)

[Fisher Coder]

OMG! I've been looking for this answer this entire two-day weekend! Thank you!!!