Starting the postgres service on Gitlab-CI - ruby-on-rails

Question

I have a Rails5 application that uses Postgres. I'm trying to use the Gitlab CI to run my spec tests when I push up new commits.
I tried setting up my file based on the documentation for configuring the .gitlab-ci.yml file and using the postgres service
I haven't changed my runner, so it's running with whatever default Gitlab uses.
.gitlab-ci.yml
services:
- postgres:9.6
variables:
POSTGRES_DB: galapagos_test
POSTGRES_USER: runner
POSTGRES_PASSWORD: ""
before_script:
# System
- apt-get update -qq
# Ruby
- ruby -v
- which ruby
# Gems
- 'echo ''gem: --no-ri --no-rdoc'' > ~/.gemrc'
- gem install bundler
- bundle install --without production --jobs $(nproc) "${FLAGS[#]}"
# App
- RAILS_ENV=test bundle exec rake db:create
- RAILS_ENV=test bundle exec rake db:migrate
rspec:
script:
- bundle exec rspec
database.yml
My Rails app database.yml is configured to use the same postgres database, username, and password specified above
development: &default
adapter: postgresql
database: galapagos_development
encoding: utf8
host: localhost
min_messages: warning
pool: 2
timeout: 5000
test:
<<: *default
database: galapagos_test
user: runner
password: ""
The Error
When the build runs it keeps failing the rake task with
$ RAILS_ENV=test bundle exec rake db:create
could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
Couldn't create database for {"adapter"=>"postgresql", "database"=>"galapagos_test", "encoding"=>"utf8", "host"=>"localhost", "min_messages"=>"warning", "pool"=>2, "timeout"=>5000, "user"=>"runner", "password"=>""}
rake aborted!
PG::ConnectionBad: could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
/usr/local/bundle/gems/pg-0.20.0/lib/pg.rb:56:in `initialize'
/usr/local/bundle/gems/pg-0.20.0/lib/pg.rb:56:in `new'
/usr/local/bundle/gems/pg-0.20.0/lib/pg.rb:56:in `connect'
Clearly the postgres service is installed (the build logs indicate that 9.6 is installed) but the psql server isn't started.
How can I start the postgres service?
I tried 2 "common" solutions I've seen posted, but they both produce errors as well.
$ /etc/init.d/postgresql restart
/bin/bash: line 69: /etc/init.d/postgresql: No such file or directory
ERROR: Job failed: exit code 1
$ service postgresql start
postgresql: unrecognized service
ERROR: Job failed: exit code 1

Answer 1

Change host: localhost to host: postgres in your database.yml.
A service is another container that is not accessible locally. So you have to access it by it's hostname - the name of the service by default. You could set an optional alias for a service if necessary documentation