How do I connect to postgres from a client machine?

December 9, 2017 14.6k views
PostgreSQL Ubuntu 16.04
heretics99
By:
heretics99

This is an extremely straightforward question. "How do I connect to Postgres DB installed on a digitalocean droplet, from an external client via command-line or via third party apps like PSequel (available for MacOS) or PGAdmin?". I am surprised that there is no direct tutorial to explain this in plain simple words. Here is what I did so far:

  1. Created a brand new spick and span droplet running Ubuntu 16.04.
  2. Installed postgres following this tutorial - https://www.digitalocean.com/community/tutorials/how-to-install-and-use-postgresql-on-ubuntu-16-04
  3. Now I have Ubuntu user "sammy", postgres user "sammy" and postgres database "sammy". I am happily able to connect to DB from within the box.
  4. All that is required now is to connect to this database, from external machine, which for some reason is a herculean task.
  5. I followed https://www.digitalocean.com/community/questions/remote-connect-to-postgresql-with-pgadmin and https://www.digitalocean.com/community/questions/how-to-connect-remotely-to-the-postgres-db-on-the-server-from-the-local-client-machine and https://askubuntu.com/questions/423165/remotely-access-postgresql-database. I changed my /etc/postgresql/9.5/main/pg_hba.conf to host all all 0.0.0.0/0 md5 and in /etc/postgresql/9.5/main/postgresql.conf added listen_addresses='*'
  6. Restarted postgres on remote server via sudo service postgresql restart
  7. [On my local Mac laptop] psql -h <IPv4 address> -p 5432 -U sammy -d sammy. However I get the error psql: FATAL: password authentication failed for user "sammy"

How do I connect to postgres server? I would highly recommend digitalocean's moderators to write a detailed but simple blog on "Connecting to Postgres from external client, along with best practises."

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6 Answers
lspencerheywood December 10, 2017

Is there any reason why you wouldn't just SSH into the droplet and run the psql command locally as the postgresql user? It seems like that would be a lot more straightforward and you wouldn't need to have postgresql remotely accessible. Making it remotely accessible doesn't seem to be the best idea from a security standpoint.

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  • heretics99 December 10, 2017

    Several reasons.

    1. I need to give DB access to non-technical people, who just dont understand ssh or cannot work on command line. But they can use apps like PSequel or PGAdmin which have a GUI interface. Therefore we cannot just ssh into the remote machine everytime to access data.
    2. I need to wire up the database to visualization tools like Google DataStudio or Periscope which can create fancy dashboards with visual graphs and pie charts. They need a database "connection URI" of the format username:password@hostname:port/database
    3. I do not want to give complete ssh access to people, because they can mess around with server and files. (I understand that I can limit user access to certain directories. But then it is more time consuming for me to create a server profile for every user and then fence it.)
    4. I need a simple solution to access data, with fewer keystrokes.
lspencerheywood December 10, 2017

If you really want to streamline it, what I would do would be to create an alias or a script on my local machine to run all the commands on my remote machine after SSH-ing in.

i.e. ssh sammy@ipaddress 'psql' or something similar to that.

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  • hebeh May 21, 2018

    might this work?

    ssh sammy@hostname "psql -Uw username -d database"

    or this

    psql -h hostname -Uw username -d database

webmaster5d575661c9d7eaa36 December 10, 2017

Well...
For desktop GUI Apps it's easy to setup user group and give ssh access
But for Google DataStudio you must provide database a access from outside.
It mean you need to setup PSQL to listen on 0.0.0.0
In my opinion that is worse than give limited SSH access to non-technical people that you know.
Possible solution is:
Setup limited SSH to provide access for desktop Apps
Use google docs to store Excel data from your server

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pavt April 4, 2018

Is there an answer to this yet? I am also attempting to do the same. remote connection should be possible.

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hebeh May 21, 2018

One more interested party here.

So far I had success with:

  1. ssh sammy@ipaddress createdb sammydb
  2. ssh sammy@ipaddress createuser sammydbuser

But not with:

  1. ssh sammy@ipaddress psql -c "alter user 'sammydbuser' with encrypted password 'some_string';"
  2. ssh sammy@ipaddress psql -c "grant all privileges on database 'sammydb' to 'sammydbuser';"

Sharing any thoughts would be greatly appreciated ...

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hebeh May 21, 2018

Oh, I found a solution to the above accidentally - it is related to the escaping characters:

this worked (at least in my case):

ssh sammy@ipaddress "psql -c \"alter user 'sammydbuser' with encrypted password 'some_string';\""
ssh sammy@ipaddress "psql -c \"grant all privileges on database 'sammydb' to 'sammydbuser';\""

note: the quote goes before psql command, then after the switch -c, you have to quote the actual command, but with an escape character. same applies to closing the quotes ...

I sincerely hope this might help someone else ...

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