Add a global rate limit for report generation

app/controllers/hledger/reports_controller.rb

@@ -11,6 +11,7 @@ module ::Hledger
     before_action :ensure_enabled
     before_action :find_topic
     before_action :enforce_rate_limit
+    before_action :enforce_global_rate_limit
 
     def show
       report_type = params[:report_type].to_s
@@ -87,6 +88,13 @@ module ::Hledger
       ).performed!
     end
 
+    def enforce_global_rate_limit
+      max = SiteSetting.hledger_global_rate_limit_per_minute.to_i
+      return if max <= 0
+
+      RateLimiter.new(nil, "hledger-reports-global", max, 60, global: true).performed!
+    end
+
     def parse_date(value)
       return nil if value.blank?
 

config/locales/server.en.yml

@@ -6,6 +6,7 @@ en:
     hledger_timeout_seconds: "Maximum number of seconds an hledger command may run"
     hledger_max_output_bytes: "Maximum number of bytes captured from hledger output"
     hledger_memory_limit_mb: "Maximum memory in megabytes the hledger process may use; set to 0 to disable the limit"
+    hledger_global_rate_limit_per_minute: "Maximum number of hledger reports that may be generated per minute across all users; set to 0 to disable the limit"
   hledger:
     errors:
       unsupported_report: "Unsupported report type."

config/settings.yml

@@ -13,3 +13,6 @@ hledger:
   hledger_memory_limit_mb:
     default: 256
     min: 0
+  hledger_global_rate_limit_per_minute:
+    default: 120
+    min: 0

spec/requests/hledger/reports_spec.rb

@@ -175,4 +175,20 @@ RSpec.describe Hledger::ReportsController do
 
     expect(response.status).to eq(404)
   end
+
+  it "enforces the global rate limit" do
+    RateLimiter.enable
+    RateLimiter.clear_all_global!
+    SiteSetting.hledger_global_rate_limit_per_minute = 1
+
+    get_report("accounts")
+    expect(response.status).to eq(200)
+
+    get_report("accounts")
+    expect(response.status).to eq(429)
+  ensure
+    RateLimiter.disable
+    RateLimiter.clear_all_global!
+    SiteSetting.hledger_global_rate_limit_per_minute = 120
+  end
 end