rake db:create throws “database does not exist” error with postgresql

Question

I\'m using rails 4.1.5 with postgresql 9.1 under Debian 7, and I\'m not able to create a database in my development environment. When I run

bin/rake db:create


        

Answer 1

I see two issues, as is04 pointed out you probably need at least a username value in your database.yml.

You also need to create the postgres role:

su - postgres
create role direct-dev with createdb login password 'password1'

Answer 2

Here is my Dockerfile for the rails project. Take a look at this part:

CMD mkdir -p tmp/pids && \
    bundle exec rake db:create && \
    bundle exec rails db:migrate && \
    bundle exec rake db:seed && \
    bundle exec puma -C config/puma.rb

Bundler 2.1.4, ruby 2.7.2, rails 6.0.3 compatible. Docker compose part:

server:
    container_name: server
    build:
      context: Server
      dockerfile: Dockerfile
      args:
        ENV: 'development'
    restart: unless-stopped
    depends_on:
      - db
    env_file:
      - ./Server/.env
    ports:
      - '9090:3000'
    volumes:
      - ./Server:/app
      - ./Server/Docker/usr/.gemrc:/root/.gemrc
    networks:
      - app-network

FROM ruby:2.7.2-alpine3.12

# env and arg variables setup
ARG APP_HOME='/app'
ARG ENV
ENV RAILS_ENV=$ENV \
    RACK_ENV=$ENV \
    RAILS_ROOT=$APP_HOME

# timezone setup
RUN apk add --update tzdata && \
    cp /usr/share/zoneinfo/Europe/London /etc/localtime && \
    echo "Europe/London" > /etc/timezone

# building in tmp dir
WORKDIR /tmp
ADD Gemfile ./

#install dependencies (bundler 2.1.4, ruby 2.7.2, rails 6.0.3 compatible) 
RUN apk add --update --virtual runtime-deps postgresql-client nodejs libffi-dev readline sqlite xz && \
    apk add --virtual build-deps build-base openssl postgresql-dev libc-dev linux-headers libxml2-dev libxslt-dev readline-dev && \
    gem install bundler -v 2.1.4 && \
    bundle install --jobs=4 && \
    apk del build-deps

# /app
WORKDIR $APP_HOME

# create dbs if no such, migrate, seed, start
CMD mkdir -p tmp/pids && \
    bundle exec rake db:create && \
    bundle exec rails db:migrate && \
    bundle exec rake db:seed && \
    bundle exec puma -C config/puma.rb

Answer 3

I had the same problem and in my case, I had used Answer.column_name in a validation in the Answer model itself. Because test database was already created on my local so RAILS_ENV=test rails db:create was working fine on local, but giving the same error in CI/CD pipeline

It was due to the reason that Rails load all the files inside app/ directory before running db:create command, and at that time as no database is there Answer.column_names failed.

I used something like this:

  validates_uniqueness_of :content, scope: (Answer.column_names - %w[id created_at updated_at]).map(&:to_sym), message: 'Duplicate answer'

which is wrong. Then I changed to:

DUPLICATE_ANSWER_SCOPE = %i[content question_id session_id]
validates_uniqueness_of :content, scope: DUPLICATE_ANSWER_SCOPE, message: 'Duplicate answer'

Answer 4

Rails 4.1 ships with spring preloader, and

New Rails 4.1 applications will ship with "springified" binstubs. This means that bin/rails and bin/rake will automatically take advantage of preloaded spring environments.

which means that the "springified" bin/rake will attempt to preload the app, which in turn will attempt to run the initilizers resulting in the problem you're seeing.

To fix / work around this you want to run the initial setup rake tasks without spring. One way to achieve that is to run it with bundler instead:

bundle exec rake db:create