Postgresql linux default password

How to Set the Default User Password in PostgreSQL

Firstly, it is important to understand that for most Unix distributions, the default Postgres user neither requires nor uses a password for authentication. Instead, depending how Postgres was originally installed and what version you are using, the default authentication method will either be ident or peer .

ident authentication uses the operating system’s identification server running at TCP port 113 to verify the user’s credentials.

peer authentication on the other hand, is used for local connections and verifies that the logged in username of the operating system matches the username for the Postgres database.

Login and Connect as Default User

For most systems, the default Postgres user is postgres and a password is not required for authentication. Thus, to add a password, we must first login and connect as the postgres user.

If you successfully connected and are viewing the psql prompt, jump down to the Changing the Password section.

If you received an error stating that the database “postgres” doesn’t exist, try connecting to the template1 database instead and if successful, continue to Changing the Password.

Authentication Error

If you receive an authentication error when attempting to connect to the psql client, you may need to alter the Postgres authentication config file (pg_hfa.conf).

Open the config file, typically located at /etc/postgresql/#.#/main/pg_hba.conf , where #.# is the Postgres version you are using:

The auth config file is a list of authentication rules. Scroll down the file until you locate the first line displaying the postgres user in the third column (if such a line exists). Uncomment the line if necessary (remove the semicolon), or otherwise if the line is missing entirely, add the following line to the top of the file and save your changes:

This authentication rule simply tells Postgres that for local connections established to all databases for the user postgres , authenticate using the peer protocol.

Note: Some older versions of Postgres prefer the default authentication method of ident, but most modern installations will utilize peer as specified above instead. You may need to test both if your results differ.

Now with your configuration file updated, repeat the steps in the Login and Connect as Default User section to try to connect to as the default postgres user. Once successful, proceed with changing the password.

Changing the Password

With a connection now established to Postgres at the psql prompt, issue the ALTER USER command to change the password for the postgres user:

If successful, Postgres will output a confirmation of ALTER ROLE as seen above.

Finally, exit the psql client by using the \q command.

You’re all done. The default postgres user now has a password associated with the account for use in your other applications.

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default postgres user and password

I’m just new to postgresql db management. I’ve been playing around with a db that I didn’t create. Trying to understand the different roles that have been created.

Does the fact that I can log in doing the following mean that the postgres user has no password set up?

and I can see that there is a password set. I found this article: http://www.postgresql.org/message-id/4D958A35.8030501@hogranch.com which seeme to confirm that the postgres user is there by default. and you have to explicitly set a password. It’s the second part about the password that I’m not sure about. Is it blank by default or set to something?

I know that if pg_hba.conf is set to trust everything from 127.0.0.1, then you can log in from the local server without specifying a password. That might be what’s happening in my case. i will test by changing the pg_hba.conf file. But it’d be nice to know what the default password is for postgres user.

postgres/.pgpass file as well.

1 Answer 1

pg_roles is not the view that can tell whether a user has a password or not, because the password field is always set to ******** no matter what.

This comes from the definition of this view (taken from version 9.3):

Note how the rolpassword column is hardcoded to reveal nothing (We may wonder why it’s there at all. Maybe for backward compatibility?)

On the other hand , there is a pg_shadow view that displays passwords as they’re stored, in a column named passwd . This view is only readable by a superuser (typically: the postgres user).

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Update Your PostgreSQL Password in Linux

PostgreSQL supports many client authentication methods, but in this case we’re only going to concern ourselves with two: password and md5.

Before Getting Started

• These instructions are intended specifically for changing a password in PostgreSQL.
• I’ll be working from a Liquid Web Core Managed CentOS 7 server, and I’ll be logged in as root.
• PostgreSQL is installed per our tutorial on: How to Install and Connect to PostgreSQL on CentOS 7.

Step #1: Switch to the PostgreSQL User: postgres

If you’re working from a default PostgreSQL installation, then PostgreSQL will be configured with the user postgres.

Since we’re logged in as root, and we’re assuming that root doesn’t have a user for PostgreSQL, switch to the default PostgreSQL user: postgres.

… then attempt a connection to PostgreSQL.

… enter your password at the prompt.

… the correct, valid response will be similar to the following.

psql (9.3.9)
Type «help» for help.

Step #2: Add/Change the PostgreSQL Password for the User: postgres

Use the following command to change the PostgreSQL password for your current user, which is now postgres.

Enter your new password, and then enter it again to confirm it.

Enter new password:
Enter it again:

Now quit the PostgreSQL interface.

Bonus Information!

You can do all of step one in exactly one command.

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What’s the default superuser username/password for postgres after a new install?

I have just installed postgres 8.4 on Ubuntu 9.10 and it has never asked me to create a superuser. Is there a default superuser and its password? If not, how do I create a new one?

5 Answers 5

CAUTION The answer about changing the UNIX password for «postgres» through «$ sudo passwd postgres» is not preferred, and can even be DANGEROUS!

This is why: By default, the UNIX account «postgres» is locked, which means it cannot be logged in using a password. If you use «sudo passwd postgres», the account is immediately unlocked. Worse, if you set the password to something weak, like «postgres», then you are exposed to a great security danger. For example, there are a number of bots out there trying the username/password combo «postgres/postgres» to log into your UNIX system.

What you should do is follow Chris James‘s answer:

To explain it a little bit. There are usually two default ways to login to PostgreSQL server:

By running the «psql» command as a UNIX user (so-called IDENT/PEER authentication), e.g.: sudo -u postgres psql . Note that sudo -u does NOT unlock the UNIX user.

by TCP/IP connection using PostgreSQL’s own managed username/password (so-called TCP authentication) (i.e., NOT the UNIX password).

So you never want to set the password for UNIX account «postgres». Leave it locked as it is by default.

Of course things can change if you configure it differently from the default setting. For example, one could sync the PostgreSQL password with UNIX password and only allow local logins. That would be beyond the scope of this question.

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What is the Default Password for PostgreSQL?

When connecting to PostgreSQL on Linux for the first time many admins have questions, especially if those admins are from the MySQL world. By default, when PostgreSQL is installed, a postgres user is also added.

If you run the command:

… you’ll see the postgres user.

The first question many ask is, “What is the default password for the user postgres?” The answer is easy… there isn’t a default password. The default authentication mode for PostgreSQL is set to ident.

… you’ll see the authentication mode is ident.

# IPv4 local connections:
host all all 127.0.0.1/32 ident
# IPv6 local connections:
host all all ::1/128 ident

What is the ident authentication method? Well, it works by taking the OS username you’re operating as and comparing it with the allowed database username(s). There is optional username mapping.

This means that in order to connect to PostgreSQL you must be logged in as the correct OS user. In this case, we are logged into the server as root. When we try to connect to PostgreSQL:

… we get the following error:

psql: FATAL: role «root» does not exist

However, if we become the default PostgreSQL user, postgres:

… then attempt a connection to PostgreSQL:

… I get the correct, valid response!

psql (9.3.9)
Type «help» for help.

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