A few quick notes on connecting to a Postgres database running on an Amazon EC2 instance using pgAdmin with its built-in SSH tunneling option.
1. If you want to connect as the postgres admin user, add a password to that user:
sudo su postgres
psql template1
alter user postgres with password 'BvcbWZV6cGOh7iUn';
Caution From now on, you will always need a password to start psql (unless some other rule takes precedence).
2. In your pg_hba.conf file, temporarily add a line that allows connecting as the postgres user to any database and from any IP address:
host all postgres 0.0.0.0/0 md5
3. Re-load the pg_hba.conf file:
pg_ctl reload –D /path/to/data/directory
4. Add a new server to pgAdmin. On the Properties tab, set Host to localhost.
On the SSH Tunnel tab, set the Tunnel host, Username, and Identity file just as you would when connecting with an SSH client:
5. Click OK to connect. Accept the key files if you trust them. Provide the password for the postgres user that you set in step 1 above. Leave the pass phrase for the identify file empty (assuming you are not using a pass phrase on that file). Do whatever work you need to do, then close the connection.
6. In pg_hba.conf, comment out the remote connection line:
#host all postgres 0.0.0.0/0 md5
7. Re-load the pg_hba.conf file:
pg_ctl reload –D /path/to/data/directory