Postgresql adapter (pg): could not connect to server
Ruby on-RailsPostgresqlRails PostgresqlPgRuby on-Rails Problem Overview
I get this error every this I run my Rails app (It cannot connect to my local Postgresql)
/Users/leonardo/.rvm/gems/ruby-1.9.3-p362/gems/activerecord-3.2.11/lib/
active_record/connection_adapters/postgresql_adapter.rb:1208:in `initialize':
could not connect to server: No such file or directory (PG::Error)
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?
I'm using Postgres.app that it's correctly running.
If I run
$ psql
I can login properly to Postgresql console.
$ which psql
/Applications/Postgres.app/Contents/MacOS/bin/psql
Gemfile
source 'https://rubygems.org'
ruby "1.9.3"
gem 'rails', '3.2.11'
gem "pg"
database.yml
development:
adapter: postgresql
encoding: unicode
username: leonardo
password:
database: zapping
port: 5432
Postgresql (Console)
$ psql
leonardo=# \l
Ruby on-Rails Solutions
Solution 1 - Ruby on-Rails
Try adding host: localhost
to your database.yml. (Based on: https://stackoverflow.com/a/10793186/919641)
Solution 2 - Ruby on-Rails
Your Pg
gem was compiled against the PostgreSQL libpq pre-installed in Mac OS X and you're using the psql
that you installed in a newer version, or vice versa.
This can be worked around by specifying a TCP/IP connection, by adding localhost
to database.yml
, but it's better to compile the Pg
gem against the libpq
for the server you're actually running. To do that, you should be able to set the PATH
environment variable to the folder with the correct pg_config
in it before compiling. In your case that'll be somewhere within Postgres.app
.
Solution 3 - Ruby on-Rails
If it does not work even after adding host: localhost
, remove the postmaster.pid
rm /usr/local/var/postgres/postmaster.pid
Solution 4 - Ruby on-Rails
you should add host: localhost
to your db config...
Solution 5 - Ruby on-Rails
I had the same problem on a Mac. Turns out that the psql I had on my path wasn't working correctly. Try launching psql by typing:
~/projects/some_project/project-rails$ psql
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?
If you see this, it indicates the psql binary on your path is attempting to connect using socket and unable to do so (for whatever reason). Since I had already downloaded pgadmin and it was connecting fine, I knew it wasn't an issue with the server.
Fixed it by adding the right version of pgsql to my PATH:
export PATH=/Applications/Postgres.app/Contents/MacOS/bin:$PATH
Now psql (and rails) are happy!
Solution 6 - Ruby on-Rails
I had this same issue. You have to actually run / start postgres. Postgres must have stopped running on my computer recently, so I had to make sure it's running by starting the postgres server
postgres -D /usr/local/var/postgres
Then the following commands (which were causing me the same error you had) all worked:
bundle exec rake db:create db:migrate
bundle exec rspec
Solution 7 - Ruby on-Rails
I had this issue. One of the comments here helped me fix the issue.
> Thanks, this answer helped me fix it. The steps I took were simple: 1) > gem uninstall pg, 2) bundle install, done. – haslo Dec 3 '13 at 20:27
gem uninstall pg
bundle install
Solution 8 - Ruby on-Rails
Since This was the first post that appeared in my search result, I have decided to post the updated fix for this. Since none of the above suggestion worked for me.
brew postgresql-upgrade-database
It upgraded postgresql data and moved my old version. I was on 9.6 instead of 10.4
Found the solution here
Solution 9 - Ruby on-Rails
find / -name 'postgresql.conf'
netstat -an | grep 5432 # => /tmp/.s.PGSQL.5432
vi /Users/admin/Library/Application\ Support/Postgres93/var/postgresql.conf
FROM: unix_socket_directories = '/tmp'
TO: unix_socket_directories = '/var/pgsql_socket'
sudo mkdir /var/pgsql_socket
sudo chmod 777 /var/pgsql_socket
Solution 10 - Ruby on-Rails
For heroku this is all you need.
heroku addons:create heroku-postgresql
production:
adapter: postgresql
encoding: unicode
host: localhost
# For details on connection pooling, see rails configuration guide
# http://guides.rubyonrails.org/configuring.html#database-pooling
pool: 5
Solution 11 - Ruby on-Rails
I just had the problem that the postgres app wasn't running on my mac...
Solution 12 - Ruby on-Rails
On Mac, I had different versions of postgresql. This problem has been solved when I tried brew switch postgresql 9.5.5
(I don't think version number matters at this point)
$ brew switch postgresql 9.5.5
Cleaning /usr/local/Cellar/postgresql/9.6.1
Cleaning /usr/local/Cellar/postgresql/9.6.5
Cleaning /usr/local/Cellar/postgresql/10.2
Cleaning /usr/local/Cellar/postgresql/10.3
Cleaning /usr/local/Cellar/postgresql/9.5.5
Cleaning /usr/local/Cellar/postgresql/9.5.4
All data will be gone away, by the way. I guess there's a brew command for doing this without switching version, which I couldn't find.
Solution 13 - Ruby on-Rails
I had the same problem on OS High sierra 10.13 I followed the instructions from this website I downloaded version 10.4 ref: https://postgresapp.com/
Then I added this to bash profile: export PATH=$PATH:/Library/PostgreSQL/10.4/bin:$PATH
re start terminal.
Open new window terminal and then type: psql -U postgres
after that you will see this message: psql (10.4) Type "help" for help.
postgres=#
Solution 14 - Ruby on-Rails
My problem was that the /etc/hosts
file changed and didn't have this crucial entry: 127.0.0.1 localhost
Solution 15 - Ruby on-Rails
I had a similar issue - when I ran psql
command in terminal I still got the same error, so that told me that it wasn't a problem with the pg gem and I should check the postgres setup itself. So I checked the postgres logs - in my case they were located at /usr/local/var/log/postgres.log
and I saw the following error:
dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.66.dylib
Referenced from: /usr/local/opt/postgresql/bin/postgres
So knowing the exact error helped me resolve the issue, in my case based on this answer I ran
brew switch icu4c 66.1
which resolved the issue after restarting postgres:
brew services restart postgresql