Update for rails 7.0.X and handle postgres password

db.rake

# apt install postgresql-client
# apt-get -y install bash-completion wget
# wget --no-check-certificate --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add -
# echo "deb http://apt.postgresql.org/pub/repos/apt/ `lsb_release -cs`-pgdg main" | sudo tee /etc/apt/sources.list.d/pgdg.list
# apt-get update
# apt-get -y install postgresql-client-12

namespace :db do

    desc "Dumps the database to backups"
    task :dump => :environment do

        dump_fmt = 'p'      # 'c' or 'p', 't', 'd'
        dump_sfx = suffix_for_format dump_fmt
        backup_dir = backup_directory true
        cmd = nil
        with_config do |app, host, db, user, passw|
            file_name = Time.now.strftime("%Y%m%d%H%M%S") + "_" + db + '.' + dump_sfx
            # puts "app = #{app}"
            # puts "host = #{host}"
            # puts "db = #{db}"
            # puts "user = #{user}"
            # puts "Password = #{passw}"
            cmd = "PGPASSWORD=#{passw}  pg_dump -F #{dump_fmt} -v -U #{user} -h #{host} -d #{db} -f #{backup_dir}/#{file_name}"
        end
        puts cmd
        exec cmd
    end

    desc "Show the existing database backups"
    task :list => :environment do
        backup_dir = backup_directory
        puts "#{backup_dir}"
        exec "/bin/ls -lt #{backup_dir}"
    end

    desc "Restores the database from a backup using PATTERN"
    task :restore, [:pat] => :environment do |task,args|
        if args.pat.present?
            cmd = nil
            with_config do |app, host, db, user, passwd|
                backup_dir = backup_directory
                files = Dir.glob("#{backup_dir}/*#{args.pat}*")
                case files.size
                when 0
                  puts "No backups found for the pattern '#{args.pat}'"
                when 1
                  file = files.first
                  fmt = format_for_file file
                  if fmt.nil?
                    puts "No recognized dump file suffix: #{file}"
                  else
                    cmd = "pg_restore -F #{fmt} -v -c -C #{file}"
                  end
                else
                  puts "Too many files match the pattern '#{args.pat}':"
                  puts ' ' + files.join("\n ")
                  puts "Try a more specific pattern"
                end
            end
            unless cmd.nil?
              Rake::Task["db:drop"].invoke
              Rake::Task["db:create"].invoke
              puts cmd
              exec cmd
            end
        else
            puts 'Please pass a pattern to the task'
        end
    end

    private

    def suffix_for_format suffix
        case suffix
        when 'c' then 'dump'
        when 'p' then 'sql'
        when 't' then 'tar'
        when 'd' then 'dir'
        else nil
        end
    end

    def format_for_file file
        case file
        when /\.dump$/ then 'c'
        when /\.sql$/  then 'p'
        when /\.dir$/  then 'd'
        when /\.tar$/  then 't'
        else nil
        end
    end

    def backup_directory create=false
        backup_dir = "#{Rails.root}/db/backups"
        if create and not Dir.exists?(backup_dir)
          puts "Creating #{backup_dir} .."
          Dir.mkdir(backup_dir)
        end
        backup_dir
    end

    def with_config
        yield Rails.application.class.module_parent_name.underscore,
          ActiveRecord::Base.connection_db_config.host,
          ActiveRecord::Base.connection_db_config.database,
          ActiveRecord::Base.connection_db_config.configuration_hash[:username],
          ActiveRecord::Base.connection_db_config.configuration_hash[:password]
    end

end

usage.sh

# Place the db.rake file in RAILS_ROOT/lib/tasks which will add the new tasks to the list of tasks.
# See the available tasks with `rails -T` or `rake -T` from the RAILS_ROOT directory

# dump the development db
rake db:dump

# dump the production db
RAILS_ENV=production rake db:dump

# dump the production db & restore it to the development db
RAILS_ENV=production rake db:dump
rake db:restore

# note: config/database.yml is used for database configuration,
#       but you will be prompted for the database user's password

version that worked for me

namespace :db do

  desc "Dumps the database to backups"
  task :dump => :environment do

    dump_fmt = 'c'
    dump_sfx = suffix_for_format dump_fmt
    backup_dir = backup_directory true
    cmd = nil
    with_config do |app, host, db, user, passw|
      file_name = Time.now.strftime("%Y%m%d%H%M%S") + "_" + db + '.' + dump_sfx
      cmd = "PGPASSWORD=#{passw}  pg_dump -F #{dump_fmt} -v -U #{user} -h #{host} -d #{db} -f #{backup_dir}/#{file_name}"
    end
    puts cmd
    exec cmd
  end

  desc "Show the existing database backups"
  task :list => :environment do
    backup_dir = backup_directory
    puts "#{backup_dir}"
    exec "/bin/ls -lt #{backup_dir}"
  end

  desc "Restores the database from a backup using PATTERN"
  task :restore, [:pat] => :environment do |task,args|
    if args.pat.present?
      cmd = nil
      with_config do |app, host, db, user, passwd|
        backup_dir = backup_directory
        files = Dir.glob("#{backup_dir}/*#{args.pat}*")
        case files.size
        when 0
          puts "No backups found for the pattern '#{args.pat}'"
        when 1
          file = files.first
          fmt = format_for_file file
          if fmt.nil?
            puts "No recognized dump file suffix: #{file}"
          else
            cmd = "pg_restore -F c -v -U #{user} -d #{db} #{file}"
          end
        else
          puts "Too many files match the pattern '#{args.pat}':"
          puts ' ' + files.join("\n ")
          puts "Try a more specific pattern"
        end
      end
      unless cmd.nil?
        Rake::Task["db:drop"].invoke
        Rake::Task["db:create"].invoke
        puts cmd
        exec cmd
      end
    else
      puts 'Please pass a pattern to the task'
    end
  end

  private

  def suffix_for_format suffix
    case suffix
    when 'c' then 'psql'
    when 'p' then 'sql'
    when 't' then 'tar'
    when 'd' then 'dir'
    else nil
    end
  end

  def format_for_file file
    case file
    when /\.psql$/ then 'c'
    when /\.sql$/  then 'p'
    when /\.dir$/  then 'd'
    when /\.tar$/  then 't'
    else nil
    end
  end

  def backup_directory create=false
    backup_dir = "#{Rails.root}/db/backups"
    if create and not Dir.exist?(backup_dir)
      puts "Creating #{backup_dir} .."
      Dir.mkdir(backup_dir)
    end
    backup_dir
  end

  def with_config
    yield Rails.application.class.module_parent_name.underscore,
      ActiveRecord::Base.connection_db_config.host,
      ActiveRecord::Base.connection_db_config.database,
      ActiveRecord::Base.connection_db_config.configuration_hash[:username],
      ActiveRecord::Base.connection_db_config.configuration_hash[:password]
  end
end