1 files changed, 166 insertions, 0 deletions
diff --git a/spec/initializers/validate_database_config_spec.rb b/spec/initializers/validate_database_config_spec.rb
new file mode 100644
index 00000000000..99e4a4b36ee
--- /dev/null
+++ b/spec/initializers/validate_database_config_spec.rb
@@ -0,0 +1,166 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'validate database config' do
+  include RakeHelpers
+  include StubENV
+
+  let(:rails_configuration) { Rails::Application::Configuration.new(Rails.root) }
+  let(:ar_configurations) { ActiveRecord::DatabaseConfigurations.new(rails_configuration.database_configuration) }
+
+  subject do
+    load Rails.root.join('config/initializers/validate_database_config.rb')
+  end
+
+  before do
+    # The `AS::ConfigurationFile` calls `read` in `def initialize`
+    # thus we cannot use `expect_next_instance_of`
+    # rubocop:disable RSpec/AnyInstanceOf
+    expect_any_instance_of(ActiveSupport::ConfigurationFile)
+      .to receive(:read).with(Rails.root.join('config/database.yml')).and_return(database_yml)
+    # rubocop:enable RSpec/AnyInstanceOf
+
+    allow(Rails.application).to receive(:config).and_return(rails_configuration)
+    allow(ActiveRecord::Base).to receive(:configurations).and_return(ar_configurations)
+  end
+
+  shared_examples 'with SKIP_DATABASE_CONFIG_VALIDATION=true' do
+    before do
+      stub_env('SKIP_DATABASE_CONFIG_VALIDATION', 'true')
+    end
+
+    it 'does not raise exception' do
+      expect { subject }.not_to raise_error
+    end
+  end
+
+  context 'when config/database.yml is valid' do
+    context 'uses legacy syntax' do
+      let(:database_yml) do
+        <<-EOS
+          production:
+            adapter: postgresql
+            encoding: unicode
+            database: gitlabhq_production
+            username: git
+            password: "secure password"
+            host: localhost
+        EOS
+      end
+
+      it 'validates configuration with a warning' do
+        expect(main_object).to receive(:warn).with /uses a deprecated syntax for/
+
+        expect { subject }.not_to raise_error
+      end
+
+      it_behaves_like 'with SKIP_DATABASE_CONFIG_VALIDATION=true'
+    end
+
+    context 'uses new syntax' do
+      let(:database_yml) do
+        <<-EOS
+          production:
+            main:
+              adapter: postgresql
+              encoding: unicode
+              database: gitlabhq_production
+              username: git
+              password: "secure password"
+              host: localhost
+        EOS
+      end
+
+      it 'validates configuration without errors and warnings' do
+        expect(main_object).not_to receive(:warn)
+
+        expect { subject }.not_to raise_error
+      end
+    end
+  end
+
+  context 'when config/database.yml is invalid' do
+    context 'uses unknown connection name' do
+      let(:database_yml) do
+        <<-EOS
+          production:
+            main:
+              adapter: postgresql
+              encoding: unicode
+              database: gitlabhq_production
+              username: git
+              password: "secure password"
+              host: localhost
+
+            another:
+              adapter: postgresql
+              encoding: unicode
+              database: gitlabhq_production
+              username: git
+              password: "secure password"
+              host: localhost
+        EOS
+      end
+
+      it 'raises exception' do
+        expect { subject }.to raise_error /This installation of GitLab uses unsupported database names/
+      end
+
+      it_behaves_like 'with SKIP_DATABASE_CONFIG_VALIDATION=true'
+    end
+
+    context 'uses replica configuration' do
+      let(:database_yml) do
+        <<-EOS
+          production:
+            main:
+              adapter: postgresql
+              encoding: unicode
+              database: gitlabhq_production
+              username: git
+              password: "secure password"
+              host: localhost
+              replica: true
+        EOS
+      end
+
+      it 'raises exception' do
+        expect { subject }.to raise_error /with 'replica: true' parameter in/
+      end
+
+      it_behaves_like 'with SKIP_DATABASE_CONFIG_VALIDATION=true'
+    end
+
+    context 'main is not a first entry' do
+      let(:database_yml) do
+        <<-EOS
+          production:
+            ci:
+              adapter: postgresql
+              encoding: unicode
+              database: gitlabhq_production_ci
+              username: git
+              password: "secure password"
+              host: localhost
+              replica: true
+
+            main:
+              adapter: postgresql
+              encoding: unicode
+              database: gitlabhq_production
+              username: git
+              password: "secure password"
+              host: localhost
+              replica: true
+        EOS
+      end
+
+      it 'raises exception' do
+        expect { subject }.to raise_error /The `main:` database needs to be defined as a first configuration item/
+      end
+
+      it_behaves_like 'with SKIP_DATABASE_CONFIG_VALIDATION=true'
+    end
+  end
+end