Rails: FATAL - Peer authentication failed for user (PG::Error)

Question

I am running my development on Ubuntu 11.10, and RubyMine

Here is my development settings for the database.yml: which RubyMine created for me

development:
  adapter: postgresql
  encoding: unicode
  database: mydb_development
  pool: 5
  username: myuser
  password:

when I try to run the app, I get this error below, it seems that I didn't create a 'project' user yet, but, how can I create a user and grant it a database in postgres ? if this is the problem, then, what is the recommended tool to use in Ubuntu for this task ? if this is not the problem, then, please advice.

Exiting
/home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:1194:in `initialize': FATAL:  Peer authentication failed for user "project" (PG::Error)
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:1194:in `new'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:1194:in `connect'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:329:in `initialize'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `postgresql_connection'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:303:in `new_connection'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:313:in `checkout_new_connection'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:237:in `block (2 levels) in checkout'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:232:in `loop'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:232:in `block in checkout'
    from /home/sam/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:229:in `checkout'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:95:in `connection'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:398:in `retrieve_connection'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:168:in `retrieve_connection'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/connection_specification.rb:142:in `connection'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/model_schema.rb:308:in `clear_cache!'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activerecord-3.2.3/lib/active_record/railtie.rb:91:in `block (2 levels) in <class:Railtie>'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:418:in `_run__757346023__prepare__404863399__callbacks'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:405:in `__run_callback'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activesupport-3.2.3/lib/active_support/callbacks.rb:81:in `run_callbacks'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/actionpack-3.2.3/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/actionpack-3.2.3/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/application/finisher.rb:47:in `block in <module:Finisher>'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/initializable.rb:30:in `instance_exec'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/initializable.rb:30:in `run'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/initializable.rb:54:in `each'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/initializable.rb:54:in `run_initializers'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/application.rb:136:in `initialize!'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/railtie/configurable.rb:30:in `method_missing'
    from /home/sam/RubymineProjects/project/config/environment.rb:5:in `<top (required)>'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `block in require'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
    from /home/sam/RubymineProjects/project/config.ru:4:in `block in <main>'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize'
    from /home/sam/RubymineProjects/project/config.ru:1:in `new'
    from /home/sam/RubymineProjects/project/config.ru:1:in `<main>'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/rack-1.4.1/lib/rack/server.rb:200:in `app'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/commands/server.rb:46:in `app'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/rack-1.4.1/lib/rack/server.rb:252:in `start'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/commands/server.rb:70:in `start'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/commands.rb:55:in `block in <top (required)>'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/commands.rb:50:in `tap'
    from /home/sam/.rvm/gems/ruby-1.9.3-p0@project/gems/railties-3.2.3/lib/rails/commands.rb:50:in `<top (required)>'
    from /home/sam/RubymineProjects/project/script/rails:6:in `require'
    from /home/sam/RubymineProjects/project/script/rails:6:in `<top (required)>'
    from -e:1:in `load'
    from -e:1:in `<main>'

Process finished with exit code 1

Compliancy

Answer 1

If you installed postresql on your server then just host: localhost to database.yml, I usually throw it in around where it says pool: 5. Otherwise if it's not localhost definitely tell that app where to find its database.

development:
  adapter: postgresql
  encoding: unicode
  database: kickrstack_development
  host: localhost
  pool: 5
  username: kickrstack
  password: secret

Make sure your user credentials are set correctly by creating a database and assigning ownership to your app's user to establish the connection. To create a new user in postgresql 9 run:

sudo -u postgres psql

set the postgresql user password if you haven't, it's just backslash password.

postgres=# \password

Create a new user and password and the user's new database:

postgres=# create user "guy_on_stackoverflow" with password 'keepitonthedl';
postgres=# create database "dcaclab_development" owner "guy_on_stackoverflow"; 

Now update your database.yml file after you've confirmed creating the database, user, password and set these privileges. Don't forget host: localhost.

Spallation

if you're still having trouble logging in and completing the connection over localhost then go back into postgresql through terminal and apply some these 8.2 conventions to establish your connecting user's privileges, syntax is GRANT ALL ON DATABASE [dbname] to [usrname]. This syntax works on psql 9+ just the same, but you probably can only toggle permissions on databases owned by the user before it will GRANT ALL: postgresql.org/docs/8.2/static/sql-grant.html – Spallation

host: localhost and pool: 5 was missing in my config. After adding them, error disappeared. – Stypsis

For me host: localhost was missing. after I added that, everything worked. This is in Ubuntu 13.04 – Tribunate

Also important to stress: DON'T FORGET THE SEMICOLONS. – Thumbnail

Personally I think it's important to be able to run the setup with rake db:setup. Otherwise you are going to have issues generating a fresh deployment environment, but this description does work for a development environment. – Pacorro

for me it worked after I changed the 'port' to the right one. I was trying to use port 5432, but then I checked my /etc/postgresql/9.5/main/postgresql.conf and in the Connection Settings section noticed, that it works on port 5433. So I changed the port setting in my database.yml and it then it worked. – Atheroma

Its confusing.. why are you setting username and password twice. That too with different values. first by sudo -u postgres psql and postgres=# \password and then by create user "guy_on_stackoverflow" with password 'keepitonthedl'; – Scabby

You sir, are a god amongst mortals. That was the one missing piece for me getting my development environment set up on my Linux desktop. I am free of the tyranny of the fruit! – Micropathology

@BentCardan Thank you for the solution, I was missing host on my database.yml file – Carbajal

Answer 2

This is the most foolproof way to get your rails app working with postgres in the development environment in Ubuntu 13.10.

1) Create rails app with postgres YAML and 'pg' gem in the Gemfile:

$ rails new my_application -d postgresql

2) Give it some CRUD functionality. If you're just seeing if postgres works, create a scaffold:

$ rails g scaffold cats name:string age:integer colour:string

3) As of rails 4.0.1 the -d postgresql option generates a YAML that doesn't include a host parameter. I found I needed this. Edit the development section and create the following parameters:

encoding: UTF-8
host: localhost
database: my_application_development
username: thisismynewusername
password: thisismynewpassword 

Note the database parameter is for a database that doesn't exit yet, and the username and password are credentials for a role that doesn't exist either. We'll create those later on!

This is how config/database.yml should look (no shame in copypasting :D ):

development:
  adapter: postgresql
  pool: 5
  # these are our new parameters
  encoding: UTF-8
  database: my_application_development
  host: localhost
  username: thisismynewusername
  password: thisismynewpassword

test:
  # this won't work 
  adapter: postgresql
  encoding: unicode
  database: my_application_test
  pool: 5
  username: my_application
  password:

production:
  # this won't work 
  adapter: postgresql
  encoding: unicode
  database: my_application_production
  pool: 5
  username: my_application
  password:

4) Start the postgres shell with this command:

$ psql

4a) You may get this error if your current user (as in your computer user) doesn't have a corresponding administration postgres role.

psql: FATAL:  role "your_username" does not exist

Now I've only installed postgres once, so I may be wrong here, but I think postgres automatically creates an administration role with the same credentials as the user you installed postgres as.

4b) So this means you need to change to the user that installed postgres to use the psql command and start the shell:

$ sudo su postgres

And then run

$ psql

5) You'll know you're in the postgres shell because your terminal will look like this:

$ psql
psql (9.1.10)
Type "help" for help.

postgres=# 

6) Using the postgresql syntax, let's create the user we specified in config/database.yml's development section:

postgres=# CREATE ROLE thisismynewusername WITH LOGIN PASSWORD 'thisismynewpassword';

Now, there's some subtleties here so let's go over them.

• The role's username, thisismynewusername, does not have quotes of any kind around it
• Specify the keyword LOGIN after the WITH. If you don't, the role will still be created, but it won't be able to log in to the database!
• The role's password, thisismynewpassword, needs to be in single quotes. Not double quotes.
• Add a semi colon on the end ;)

You should see this in your terminal:

postgres=#
CREATE ROLE
postgres=#

That means, "ROLE CREATED", but postgres' alerts seem to adopt the same imperative conventions of git hub.

7) Now, still in the postgres shell, we need to create the database with the name we set in the YAML. Make the user we created in step 6 its owner:

postgres=# CREATE DATABASE my_application_development OWNER thisismynewusername;

You'll know if you were successful because you'll get the output:

CREATE DATABASE

8) Quit the postgres shell:

\q

9) Now the moment of truth:

$ RAILS_ENV=development rake db:migrate

If you get this:

==  CreateCats: migrating =================================================
-- create_table(:cats)
   -> 0.0028s
==  CreateCats: migrated (0.0028s) ========================================

Congratulations, postgres is working perfectly with your app.

9a) On my local machine, I kept getting a permission error. I can't remember it exactly, but it was an error along the lines of

Can't access the files. Change permissions to 666.

Though I'd advise thinking very carefully about recursively setting write privaledges on a production machine, locally, I gave my whole app read write privileges like this:

9b) Climb up one directory level:

$ cd ..

9c) Set the permissions of the my_application directory and all its contents to 666:

$ chmod -R 0666 my_application

9d) And run the migration again:

$ RAILS_ENV=development rake db:migrate

==  CreateCats: migrating =================================================
-- create_table(:cats)
   -> 0.0028s
==  CreateCats: migrated (0.0028s) ========================================

Some tips and tricks if you muck up

Try these before restarting all of these steps:

The mynewusername user doesn't have privileges to CRUD to the my_app_development database? Drop the database and create it again with mynewusername as the owner:

1) Start the postgres shell:

$ psql

2) Drop the my_app_development database. Be careful! Drop means utterly delete!

postgres=# DROP DATABASE my_app_development;

3) Recreate another my_app_development and make mynewusername the owner:

postgres=# CREATE DATABASE my_application_development OWNER mynewusername;

4) Quit the shell:

postgres=# \q

The mynewusername user can't log into the database? Think you wrote the wrong password in the YAML and can't quite remember the password you entered using the postgres shell? Simply alter the role with the YAML password:

1) Open up your YAML, and copy the password to your clipboard:

 development:
      adapter: postgresql
      pool: 5
      # these are our new parameters
      encoding: UTF-8
      database: my_application_development
      host: localhost
      username: thisismynewusername
      password: musthavebeenverydrunkwheniwrotethis

2) Start the postgres shell:

$ psql    

3) Update mynewusername's password. Paste in the password, and remember to put single quotes around it:

postgres=# ALTER ROLE mynewusername PASSWORD `musthavebeenverydrunkwheniwrotethis`;

4) Quit the shell:

postgres=# \q

Trying to connect to localhost via a database viewer such as Dbeaver, and don't know what your postgres user's password is? Change it like this:

1) Run passwd as a superuser:

$ sudo passwd postgres

2) Enter your accounts password for sudo (nothing to do with postgres):

[sudo] password for starkers: myaccountpassword

3) Create the postgres account's new passwod:

Enter new UNIX password: databasesarefun
Retype new UNIX password: databasesarefun
passwd: password updated successfully

Getting this error message?:

Run `$ bin/rake db:create db:migrate` to create your database
$ rake db:create db:migrate
PG::InsufficientPrivilege: ERROR:  permission denied to create database

4) You need to give your user the ability to create databases. From the psql shell:

ALTER ROLE thisismynewusername WITH CREATEDB

Chapatti

I wish I could give you more +1 s for this brilliant solution, I'd be even happier if it worked for me. still brilliant answer. quick question, are those backticks around the password in alter role? also, you don't need to use backticks earlier do you? – Moises

@MikeH-R Thanks, shame it doesn't work for you! Are you sure your relevant YAML has host: localhost? That was the real gotcha for me. Around the password you need single quotes. On my keyboard that's shift + @. With the psql shell you only need single quotes around some parameters. You need them around the password, and not around role's name, for example. It's very fiddly to be honest, but okay once you know it's nuances :) – Chapatti

@MikeH-R I've tweak my answer to make things clearer. Consider having another crack at it! – Chapatti

sorted it out now, thanks again for a brilliant answer, most other answers I encountered were about loosening security which is obviously no good in production. – Moises

for the CREATE ROLE and CREATE DATABASE parts you can also alternatively do sudo -u postgres createuser -s {}; sudo -u postgres psql; postgres=# \password {} and rake db:create – Antionetteantioxidant

why is your password blank in the db yml test section, it gives no password supplied error – Antionetteantioxidant

Answer 3

For permanent solution:

The problem is with your pg_hba. This line:

local   all             postgres                                peer

Should be

local   all             postgres                                md5

Then restart your postgresql server after changing this file.

If you're on Linux, command would be

sudo service postgresql restart

Leith

Thank you! This is the real answer. – Martamartaban

Save everyone a step, if you need to know where pg_hba is: SHOW hba_file; – Hesione

Answer 4

I was facing same problem on Ubuntu machine so I removed this error by following some steps. Switch to postgres user

$ sudo su - postgres

it will ask for password and by default password is postgres

After switch the user to postgres, open psql console

$ psql

so check the version of postgres if multiple versions are available

psql=# select VERSION();

PostgreSQL 9.1.13 on x86_64-unk....         # so version is 9.1

Now Open postgres user

vim /etc/postgresql/9.1/main/pg_hba.conf

9.1 is version return form upper command

and replace

local   all             postgres                                peer

to

local   all             postgres                                md5

Restart the service

sudo service postgresql restart

I write steps on my blog also

http://tarungarg402.blogspot.in/2014/10/set-up-postgresql-on-ubuntu.html

Dull

You have given right answer, only missed one thing you do not need to check the version. You can change the password by running this command after psql Alter user "username" set password 'xyz'; – Decrepitate

Remember that md5 authentication requires a non-null password for your database user (just got bit by that today while trying to maximize laziness when creating a a Rails application). – Bani

Answer 5

Adding host: localhost was the magic for me

development:
  adapter: postgresql
  database: database_name_here
  host: localhost
  username: user_name_here

Swaine

Answer 6

You can go to your /var/lib/pgsql/data/pg_hba.conf file and add trust in place of Ident It worked for me.

local   all all trust
host    all 127.0.0.1/32    trust

For further details refer to this issue Ident authentication failed for user

Zsigmondy

Centos 6.6, try: /var/lib/pgsql/9.2/data/pg_hba.conf – Deventer

Answer 7

I also faced this same issue while working in my development environment, the problem was that I left host: localhost commented out in the config/database.yml file.

So my application could not connect to the PostgreSQL database, simply uncommenting it solved the issue.

development:
  <<: *default
  database: database_name

  username: database_username 

  password: database_password

  host: localhost

That's all.

I hope this helps

Sauls

Answer 8

If you get that error message (Peer authentication failed for user (PG::Error)) when running unit tests, make sure the test database exists.

Trounce

Answer 9

In my case i was missing host: localhost in:

development:
  host: localhost

Mulch