Add latest changes from gitlab-org/gitlab@master

1 files changed, 48 insertions, 7 deletions

diff --git a/app/services/prometheus/proxy_variable_substitution_service.rb b/app/services/prometheus/proxy_variable_substitution_service.rb
index ca56292e9d6..b34afaf80b8 100644
--- a/app/services/prometheus/proxy_variable_substitution_service.rb
+++ b/app/services/prometheus/proxy_variable_substitution_service.rb
@@ -4,7 +4,10 @@ module Prometheus
   class ProxyVariableSubstitutionService < BaseService
     include Stepable
 
-    steps :add_params_to_result, :substitute_ruby_variables
+    steps :validate_variables,
+      :add_params_to_result,
+      :substitute_ruby_variables,
+      :substitute_liquid_variables
 
     def initialize(environment, params = {})
       @environment, @params = environment, params.deep_dup
@@ -16,24 +19,45 @@ module Prometheus
 
     private
 
+    def validate_variables(_result)
+      return success unless variables
+
+      unless variables.is_a?(Array) && variables.size.even?
+        return error(_('Optional parameter "variables" must be an array of keys and values. Ex: [key1, value1, key2, value2]'))
+      end
+
+      success
+    end
+
     def add_params_to_result(result)
       result[:params] = params
 
       success(result)
     end
 
+    def substitute_liquid_variables(result)
+      return success(result) unless query(result)
+
+      result[:params][:query] =
+        TemplateEngines::LiquidService.new(query(result)).render(full_context)
+
+      success(result)
+    rescue TemplateEngines::LiquidService::RenderError => e
+      error(e.message)
+    end
+
     def substitute_ruby_variables(result)
-      return success(result) unless query
+      return success(result) unless query(result)
 
       # The % operator doesn't replace variables if the hash contains string
       # keys.
-      result[:params][:query] = query % predefined_context.symbolize_keys
+      result[:params][:query] = query(result) % predefined_context.symbolize_keys
 
       success(result)
     rescue TypeError, ArgumentError => exception
       log_error(exception.message)
-      Gitlab::ErrorTracking.track_exception(exception, extra: {
-        template_string: query,
+      Gitlab::ErrorTracking.track_exception(exception, {
+        template_string: query(result),
         variables: predefined_context
       })
 
@@ -44,8 +68,25 @@ module Prometheus
       @predefined_context ||= Gitlab::Prometheus::QueryVariables.call(@environment)
     end
 
-    def query
-      params[:query]
+    def full_context
+      @full_context ||= predefined_context.reverse_merge(variables_hash)
+    end
+
+    def variables
+      params[:variables]
+    end
+
+    def variables_hash
+      # .each_slice(2) converts ['key1', 'value1', 'key2', 'value2'] into
+      # [['key1', 'value1'], ['key2', 'value2']] which is then converted into
+      # a hash by to_h: {'key1' => 'value1', 'key2' => 'value2'}
+      # to_h will raise an ArgumentError if the number of elements in the original
+      # array is not even.
+      variables&.each_slice(2).to_h
+    end
+
+    def query(result)
+      result[:params][:query]
     end
   end
 end