PG ConnectionBad Could not connect to server - ruby-on-rails

Question

Full error is:
PG::ConnectionBad (could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
):
pg (1.2.3) lib/pg.rb:58:in `initialize'
pg (1.2.3) lib/pg.rb:58:in `new'
pg (1.2.3) lib/pg.rb:58:in `connect'
activerecord (6.0.2.2) lib/active_record/connection_adapters/postgresql_adapter.rb:46:in `postgresql_connection'
activerecord (6.0.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:889:in `new_connection'
activerecord (6.0.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:933:in `checkout_new_connection'
activerecord (6.0.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:912:in `try_to_checkout_new_connection'
activerecord (6.0.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:873:in `acquire_connection'
activerecord (6.0.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:595:in `checkout'
activerecord (6.0.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:439:in `connection'
activerecord (6.0.2.2) lib/active_record/connection_adapters/abstract/connection_pool.rb:1121:in `retrieve_connection'
activerecord (6.0.2.2) lib/active_record/connection_handling.rb:238:in `retrieve_connection'
activerecord (6.0.2.2) lib/active_record/connection_handling.rb:206:in `connection'
activerecord (6.0.2.2) lib/active_record/migration.rb:562:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/callbacks.rb:27:in `block in call'
activesupport (6.0.2.2) lib/active_support/callbacks.rb:101:in `run_callbacks'
actionpack (6.0.2.2) lib/action_dispatch/middleware/callbacks.rb:26:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/actionable_exceptions.rb:17:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/debug_exceptions.rb:32:in `call'
web-console (4.0.1) lib/web_console/middleware.rb:132:in `call_app'
web-console (4.0.1) lib/web_console/middleware.rb:28:in `block in call'
web-console (4.0.1) lib/web_console/middleware.rb:17:in `catch'
web-console (4.0.1) lib/web_console/middleware.rb:17:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
railties (6.0.2.2) lib/rails/rack/logger.rb:38:in `call_app'
railties (6.0.2.2) lib/rails/rack/logger.rb:26:in `block in call'
activesupport (6.0.2.2) lib/active_support/tagged_logging.rb:80:in `block in tagged'
activesupport (6.0.2.2) lib/active_support/tagged_logging.rb:28:in `tagged'
activesupport (6.0.2.2) lib/active_support/tagged_logging.rb:80:in `tagged'
railties (6.0.2.2) lib/rails/rack/logger.rb:26:in `call'
sprockets-rails (3.2.1) lib/sprockets/rails/quiet_assets.rb:13:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/request_id.rb:27:in `call'
rack (2.2.2) lib/rack/method_override.rb:24:in `call'
rack (2.2.2) lib/rack/runtime.rb:22:in `call'
activesupport (6.0.2.2) lib/active_support/cache/strategy/local_cache_middleware.rb:29:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/static.rb:126:in `call'
rack (2.2.2) lib/rack/sendfile.rb:110:in `call'
actionpack (6.0.2.2) lib/action_dispatch/middleware/host_authorization.rb:83:in `call'
webpacker (4.2.2) lib/webpacker/dev_server_proxy.rb:23:in `perform_request'
rack-proxy (0.6.5) lib/rack/proxy.rb:57:in `call'
railties (6.0.2.2) lib/rails/engine.rb:526:in `call'
puma (3.12.4) lib/puma/configuration.rb:227:in `call'
puma (3.12.4) lib/puma/server.rb:675:in `handle_request'
puma (3.12.4) lib/puma/server.rb:476:in `process_client'
puma (3.12.4) lib/puma/server.rb:334:in `block in run'
puma (3.12.4) lib/puma/thread_pool.rb:135:in `block in spawn_thread'
I tried rm the postmaster.pid but then it prints no such file. I also tried restarting postgresql multiple times but it keeps printing the same exact error.
I know that there is not much thats all the info I have regarding the problem

Answer 1

I will send you some steps that help me with this issue:
CHECKING POSTGRES STATUS AND RUNNING PORT (if it is on 5432):
Ubuntu/Linux Distros (Terminal):
$ pg_lsclusters
or
$ systemctl status postgresql.service
or
$ service postgresql status
Windows:
Ctrl+R type services.msc
You should find the postgres status and the port which it is running
STARTING POSTGRES SERVICE:
Ubuntu/Linux Distros (Terminal):
$ systemctl start postgresql.service
or
$ sudo service postgresql start
Windows
Ctrl + R type services.msc find your postgres service and just start it.
CHECKING AND CREATING USER ROLE ON POSTGRES
First connect to the database:
$ sudo su postgres
$ psql
Then check if your role is created with the command:
$ \du
If it's not created yet you can create by using:
$ CREATE role name_of_your_role_here WITH createdb login password 'your_password_here';
After that you could try again to connect to the database:
don't forget to use
rake db:create
rake db:migrate
and configure database.yml file on your application
Change Client Authentication Method on PG_HBA.CONF
You can see more details of it right here: pg_hba.conf
You would probably use md5 password method or no auth at all for tests purpose
To do that, you could change the METHOD column of your localhost from peer(default) to md5
You can find this file on:
LINUX DISTROS:
cd /etc/postgresql/your postgres version here/main/pg_hba.conf
WINDOWS:
C:/Porgram Files/PostgresSQL/your postgres version
her/data/pg_hba.conf
Option method with simple user/password:
TYPE DATABASE USER ADDRESS METHOD
IPv4 local connections:
host all all 127.0.0.1/32 md5 <= CHANGE HERE
Option method with no Password:
TYPE DATABASE USER ADDRESS METHOD
IPv4 local connections:
host all all 127.0.0.1/32 trust <= CHANGE HERE

Answer 2

Windows 10
In my case, PostgreSQL Server wasn't running so I had to start it as follows:
Open the Run app
Type services.msc
Find postgresql-x64-13 - PostgreSQL Server 13 (Its description is: Provides relational database storage.)
Right click, and select Start