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.

5 files changed, 57 insertions, 5 deletions

diff --git a/changelogs/unreleased/enable-specific-embeds.yml b/changelogs/unreleased/enable-specific-embeds.yml
new file mode 100644
index 00000000000..f2e591621a8
--- /dev/null
+++ b/changelogs/unreleased/enable-specific-embeds.yml
@@ -0,0 +1,5 @@
+---
+title: Enable embedding of specific metrics charts in GFM
+merge_request: 31304
+author:
+type: added
diff --git a/lib/banzai/filter/inline_metrics_filter.rb b/lib/banzai/filter/inline_metrics_filter.rb
index 0120cc37d6f..29f526d3421 100644
--- a/lib/banzai/filter/inline_metrics_filter.rb
+++ b/lib/banzai/filter/inline_metrics_filter.rb
@@ -22,10 +22,25 @@ module Banzai
           params['namespace'],
           params['project'],
           params['environment'],
-          embedded: true
+          embedded: true,
+          **query_params(params)
         )
       end
 
+      # Parses query params out from full string into hash.
+      # If multiple values are given for a parameter, they
+      # will be captured in an array.
+      # Ex) '?title=Title&group=Group' --> { title: 'Title', group: Group }
+      def query_params(params)
+        return {} unless params['query']
+
+        CGI.parse(params['query'][1..-1]).map do |key, value|
+          target = value.length == 1 ? value.first : value
+
+          [key.to_sym, target]
+        end.to_h
+      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.
diff --git a/lib/gitlab/metrics/dashboard/url.rb b/lib/gitlab/metrics/dashboard/url.rb
index b197e7ca86b..83d0a1cdf49 100644
--- a/lib/gitlab/metrics/dashboard/url.rb
+++ b/lib/gitlab/metrics/dashboard/url.rb
@@ -21,8 +21,8 @@ module Gitlab
                 \/(?<environment>\d+)
                 \/metrics
                 (?<query>
-                  \?[a-z0-9_=-]+
-                  (&[a-z0-9_=-]+)*
+                  \?[%.+a-zA-Z0-9_=-]+
+                  (&[%.+a-zA-Z0-9_=-]+)*
                 )?
                 (?<anchor>\#[a-z0-9_-]+)?
               )
diff --git a/spec/lib/banzai/filter/inline_metrics_filter_spec.rb b/spec/lib/banzai/filter/inline_metrics_filter_spec.rb
index 772c94e3180..1dfec8118ff 100644
--- a/spec/lib/banzai/filter/inline_metrics_filter_spec.rb
+++ b/spec/lib/banzai/filter/inline_metrics_filter_spec.rb
@@ -51,5 +51,30 @@ describe Banzai::Filter::InlineMetricsFilter do
         end
       end
     end
+
+    context 'with dashboard params specified' do
+      let(:params) do
+        [
+          'foo',
+          'bar',
+          12,
+          {
+            embedded: true,
+            dashboard: 'config%2Fprometheus%2Fcommon_metrics.yml',
+            group: 'System+metrics+%28Kubernetes%29',
+            title: 'Core+Usage+%28Pod+Average%29',
+            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
diff --git a/spec/lib/gitlab/metrics/dashboard/url_spec.rb b/spec/lib/gitlab/metrics/dashboard/url_spec.rb
index 34bc6359414..edd11bf8023 100644
--- a/spec/lib/gitlab/metrics/dashboard/url_spec.rb
+++ b/spec/lib/gitlab/metrics/dashboard/url_spec.rb
@@ -9,14 +9,21 @@ 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: 123345456,
+        dashboard: 'config%2Fprometheus%2Fcommon_metrics.yml',
+        anchor: 'title'
+      )
 
       expected_params = {
         'url' => url,
         'namespace' => 'foo',
         'project' => 'bar',
         'environment' => '1',
-        'query' => '?start=123345456',
+        'query' => '?dashboard=config%252Fprometheus%252Fcommon_metrics.yml&start=123345456',
         'anchor' => '#title'
       }