Import common metrics into database.

This MR backports PrometheusMetric model to CE
and adds: common, identifier to figure out what kind of metric is used.

1 files changed, 119 insertions, 0 deletions

diff --git a/spec/db/importers/common_metrics_importer_spec.rb b/spec/db/importers/common_metrics_importer_spec.rb
new file mode 100644
index 00000000000..81eba6377c3
--- /dev/null
+++ b/spec/db/importers/common_metrics_importer_spec.rb
@@ -0,0 +1,119 @@
+require 'rails_helper'
+require Rails.root.join("db", "importers", "common_metrics_importer.rb")
+
+describe Importers::PrometheusMetric do
+  it 'group enum equals ::PrometheusMetric' do
+    expect(described_class.groups).to eq(::PrometheusMetric.groups)
+  end
+
+  it 'GROUP_TITLES equals ::PrometheusMetric' do
+    expect(described_class::GROUP_TITLES).to eq(::PrometheusMetric::GROUP_TITLES)
+  end
+end
+
+describe Importers::CommonMetricsImporter do
+  subject { described_class.new }
+
+  context "does import common_metrics.yml" do
+    let(:groups) { subject.content }
+    let(:metrics) { groups.map { |group| group['metrics'] }.flatten }
+    let(:queries) { metrics.map { |group| group['queries'] }.flatten }
+    let(:query_ids) { queries.map { |query| query['id'] } }
+
+    before do
+      subject.execute
+    end
+
+    it "has the same amount of groups" do
+      expect(PrometheusMetric.common.group(:group).count.count).to eq(groups.count)
+    end
+
+    it "has the same amount of metrics" do
+      expect(PrometheusMetric.common.group(:group, :title).count.count).to eq(metrics.count)
+    end
+
+    it "has the same amount of queries" do
+      expect(PrometheusMetric.common.count).to eq(queries.count)
+    end
+
+    it "does not have duplicate IDs" do
+      expect(query_ids).to eq(query_ids.uniq)
+    end
+
+    it "imports all IDs" do
+      expect(PrometheusMetric.common.pluck(:identifier)).to eq(query_ids)
+    end
+  end
+
+  context 'does import properly all fields' do
+    let(:query_identifier) { 'response-metric' }
+    let(:group) do
+      {
+        group: 'Response metrics (NGINX Ingress)',
+        metrics: [{
+          title: "Throughput",
+          y_label: "Requests / Sec",
+          queries: [{
+            id: query_identifier,
+            query_range: 'my-query',
+            unit: 'my-unit',
+            label: 'status code'
+          }]
+        }]
+      }
+    end
+
+    before do
+      expect(subject).to receive(:content) { [group.deep_stringify_keys] }
+    end
+
+    shared_examples 'stores metric' do
+      let(:metric) { PrometheusMetric.find_by(identifier: query_identifier) }
+
+      it 'with all data' do
+        expect(metric.group).to eq('nginx_ingress')
+        expect(metric.title).to eq('Throughput')
+        expect(metric.y_label).to eq('Requests / Sec')
+        expect(metric.unit).to eq('my-unit')
+        expect(metric.legend).to eq('status code')
+        expect(metric.query).to eq('my-query')
+      end
+    end
+
+    context 'if ID is missing' do
+      let(:query_identifier) { }
+
+      it 'raises exception' do
+        expect { subject.execute }.to raise_error(described_class::MissingQueryId)
+      end
+    end
+
+    context 'for existing common metric with different ID' do
+      let!(:existing_metric) { create(:prometheus_metric, :common, identifier: 'my-existing-metric') }
+
+      before do
+        subject.execute
+      end
+
+      it_behaves_like 'stores metric' do
+        it 'and existing metric is not changed' do
+          expect(metric).not_to eq(existing_metric)
+        end
+      end
+    end
+
+    context 'when metric with ID exists ' do
+      let!(:existing_metric) { create(:prometheus_metric, :common, identifier: 'response-metric') }
+
+      before do
+        subject.execute
+      end
+
+      it_behaves_like 'stores metric' do
+        it 'and existing metric is changed' do
+          expect(metric).to eq(existing_metric)
+        end
+      end
+    end
+  end
+end
\ No newline at end of file