Support query parameters in metrics embeds

https://gitlab.com/gitlab-org/gitlab-ce/issues/62971

Adds support for embedding specific charts from the
metrics dashboard. Expected parameters are dashboard,
title, group, and y_label.

changelogs/unreleased/enable-specific-embeds.yml

+---
+title: Enable embedding of specific metrics charts in GFM
+merge_request: 31304
+author:
+type: added

lib/banzai/filter/inline_metrics_filter.rb

@@ -15,17 +15,6 @@ module Banzai
         )
       end
 
-      # Endpoint FE should hit to collect the appropriate
-      # chart information
-      def metrics_dashboard_url(params)
-        Gitlab::Metrics::Dashboard::Url.build_dashboard_url(
-          params['namespace'],
-          params['project'],
-          params['environment'],
-          embedded: true
-        )
-      end
-
       # Search params for selecting metrics links. A few
       # simple checks is enough to boost performance without
       # the cost of doing a full regex match.
@@ -38,6 +27,28 @@ module Banzai
       def link_pattern
         Gitlab::Metrics::Dashboard::Url.regex
       end
+
+      private
+
+      # Endpoint FE should hit to collect the appropriate
+      # chart information
+      def metrics_dashboard_url(params)
+        Gitlab::Metrics::Dashboard::Url.build_dashboard_url(
+          params['namespace'],
+          params['project'],
+          params['environment'],
+          embedded: true,
+          **query_params(params['url'])
+        )
+      end
+
+      # Parses query params out from full url string into hash.
+      #
+      # Ex) 'https://<root>/<project>/<environment>/metrics?title=Title&group=Group'
+      #       --> { title: 'Title', group: 'Group' }
+      def query_params(url)
+        Gitlab::Metrics::Dashboard::Url.parse_query(url)
+      end
     end
   end
 end

lib/gitlab/metrics/dashboard/url.rb

@@ -21,14 +21,26 @@ module Gitlab
                 \/(?<environment>\d+)
                 \/metrics
                 (?<query>
-                  \?[a-z0-9_=-]+
-                  (&[a-z0-9_=-]+)*
+                  \?[a-zA-Z0-9%.()+_=-]+
+                  (&[a-zA-Z0-9%.()+_=-]+)*
                 )?
                 (?<anchor>\#[a-z0-9_-]+)?
               )
             }x
           end
 
+          # Parses query params out from full url string into hash.
+          #
+          # Ex) 'https://<root>/<project>/<environment>/metrics?title=Title&group=Group'
+          #       --> { title: 'Title', group: 'Group' }
+          def parse_query(url)
+            query_string = URI.parse(url).query.to_s
+
+            CGI.parse(query_string)
+              .transform_values { |value| value.first }
+              .symbolize_keys
+          end
+
           # Builds a metrics dashboard url based on the passed in arguments
           def build_dashboard_url(*args)
             Gitlab::Routing.url_helpers.metrics_dashboard_namespace_project_environment_url(*args)

spec/features/markdown/metrics_spec.rb

@@ -26,13 +26,31 @@ describe 'Metrics rendering', :js, :use_clean_rails_memory_store_caching do
     restore_host
   end
 
-  context 'with deployments and related deployable present' do
-    it 'shows embedded metrics' do
+  it 'shows embedded metrics' do
+    visit project_issue_path(project, issue)
+
+    expect(page).to have_css('div.prometheus-graph')
+    expect(page).to have_text('Memory Usage (Total)')
+    expect(page).to have_text('Core Usage (Total)')
+  end
+
+  context 'when dashboard params are in included the url' do
+    let(:metrics_url) { metrics_project_environment_url(project, environment, **chart_params) }
+
+    let(:chart_params) do
+      {
+        group: 'System metrics (Kubernetes)',
+        title: 'Memory Usage (Pod average)',
+        y_label: 'Memory Used per Pod (MB)'
+      }
+    end
+
+    it 'shows embedded metrics for the specifiec chart' do
       visit project_issue_path(project, issue)
 
       expect(page).to have_css('div.prometheus-graph')
-      expect(page).to have_text('Memory Usage (Total)')
-      expect(page).to have_text('Core Usage (Total)')
+      expect(page).to have_text(chart_params[:title])
+      expect(page).to have_text(chart_params[:y_label])
     end
   end
 

spec/lib/banzai/filter/inline_metrics_filter_spec.rb

@@ -12,7 +12,7 @@ describe Banzai::Filter::InlineMetricsFilter do
     let(:url) { 'https://foo.com' }
 
     it 'leaves regular non-metrics links unchanged' do
-      expect(doc.to_s).to eq input
+      expect(doc.to_s).to eq(input)
     end
   end
 
@@ -21,7 +21,7 @@ describe Banzai::Filter::InlineMetricsFilter do
     let(:url) { urls.metrics_namespace_project_environment_url(*params) }
 
     it 'leaves the original link unchanged' do
-      expect(doc.at_css('a').to_s).to eq input
+      expect(doc.at_css('a').to_s).to eq(input)
     end
 
     it 'appends a metrics charts placeholder with dashboard url after metrics links' do
@@ -29,7 +29,7 @@ describe Banzai::Filter::InlineMetricsFilter do
       expect(node).to be_present
 
       dashboard_url = urls.metrics_dashboard_namespace_project_environment_url(*params, embedded: true)
-      expect(node.attribute('data-dashboard-url').to_s).to eq dashboard_url
+      expect(node.attribute('data-dashboard-url').to_s).to eq(dashboard_url)
     end
 
     context 'when the metrics dashboard link is part of a paragraph' do
@@ -37,9 +37,34 @@ describe Banzai::Filter::InlineMetricsFilter do
       let(:input) { %(<p>#{paragraph}</p>) }
 
       it 'appends the charts placeholder after the enclosing paragraph' do
-        expect(doc.at_css('p').to_s).to include paragraph
+        expect(doc.at_css('p').to_s).to include(paragraph)
         expect(doc.at_css('.js-render-metrics')).to be_present
       end
     end
+
+    context 'with dashboard params specified' do
+      let(:params) do
+        [
+          'foo',
+          'bar',
+          12,
+          {
+            embedded: true,
+            dashboard: 'config/prometheus/common_metrics.yml',
+            group: 'System metrics (Kubernetes)',
+            title: 'Core Usage (Pod Average)',
+            y_label: 'Cores per Pod'
+          }
+        ]
+      end
+
+      it 'appends a metrics charts placeholder with dashboard url after metrics links' do
+        node = doc.at_css('.js-render-metrics')
+        expect(node).to be_present
+
+        dashboard_url = urls.metrics_dashboard_namespace_project_environment_url(*params)
+        expect(node.attribute('data-dashboard-url').to_s).to eq(dashboard_url)
+      end
+    end
   end
 end

spec/lib/gitlab/metrics/dashboard/url_spec.rb

@@ -9,14 +9,22 @@ describe Gitlab::Metrics::Dashboard::Url do
     end
 
     it 'matches a metrics dashboard link with named params' do
-      url = Gitlab::Routing.url_helpers.metrics_namespace_project_environment_url('foo', 'bar', 1, start: 123345456, anchor: 'title')
+      url = Gitlab::Routing.url_helpers.metrics_namespace_project_environment_url(
+        'foo',
+        'bar',
+        1,
+        start: '2019-08-02T05:43:09.000Z',
+        dashboard: 'config/prometheus/common_metrics.yml',
+        group: 'awesome group',
+        anchor: 'title'
+      )
 
       expected_params = {
         'url' => url,
         'namespace' => 'foo',
         'project' => 'bar',
         'environment' => '1',
-        'query' => '?start=123345456',
+        'query' => '?dashboard=config%2Fprometheus%2Fcommon_metrics.yml&group=awesome+group&start=2019-08-02T05%3A43%3A09.000Z',
         'anchor' => '#title'
       }