Add Elastic APM integration.

https://www.elastic.co/guide/en/apm/agent/ruby/4.x/introduction.html

Gemfile

@@ -56,6 +56,7 @@ gem "rbtrace"
 gem "good_job"
 gem "crass"
 gem "public_suffix"
+gem "elastic-apm"
 
 group :development do
   gem 'rubocop', require: false

Gemfile.lock

@@ -166,6 +166,9 @@ GEM
       railties (>= 3.2)
     e2mmap (0.1.0)
     ed25519 (1.3.0)
+    elastic-apm (4.5.0)
+      concurrent-ruby (~> 1.0)
+      http (>= 3.0)
     erubi (1.10.0)
     et-orbi (1.2.7)
       tzinfo
@@ -535,6 +538,7 @@ DEPENDENCIES
   dotenv-rails
   dtext_rb!
   ed25519
+  elastic-apm
   factory_bot
   ffaker
   ffi

app/logical/danbooru_logger.rb

@@ -42,10 +42,10 @@ class DanbooruLogger
   # @param session the Rails session
   # @param user [User] the current user
   def self.add_session_attributes(request, session, user)
-    add_attributes("request", { path: request.path })
+    #add_attributes("request", { path: request.path })
-    add_attributes("request.headers", header_params(request))
+    #add_attributes("request.headers", header_params(request))
-    add_attributes("request.params", request_params(request))
+    add_attributes("param", request_params(request))
-    add_attributes("session.params", session_params(session))
+    add_attributes("session", session_params(session))
     add_attributes("user", user_params(request, user))
   end
 
@@ -70,10 +70,10 @@ class DanbooruLogger
       id: user&.id,
       name: user&.name,
       level: user&.level_string,
-      ip: request.remote_ip,
+      #ip: request.remote_ip,
-      country: CurrentUser.country,
+      #country: CurrentUser.country,
-      safe_mode: CurrentUser.safe_mode?,
+      #safe_mode: CurrentUser.safe_mode?,
-      bot: UserAgent.new(request.headers["HTTP_USER_AGENT"]).is_bot?,
+      #bot: UserAgent.new(request.headers["HTTP_USER_AGENT"]).is_bot?,
     }
   end
 
@@ -86,12 +86,18 @@ class DanbooruLogger
   private_class_method
 
   def self.log_attributes(attributes)
+    attributes.each do |key, value|
+      ElasticAPM.set_label(key, value)
+    end
   end
 
   def self.log_exception(exception, expected: false, custom_params: {})
+    ElasticAPM.report(exception, handled: expected)
   end
 
   def self.log_event(level, message: nil, **params)
+    ElasticAPM.set_custom_context(params)
+    ElasticAPM.report_message(message)
   end
 
   # flatten_hash({ foo: { bar: { baz: 42 } } })

app/logical/session_loader.rb

@@ -117,7 +117,7 @@ class SessionLoader
   def authenticate_basic_auth
     credentials = ::Base64.decode64(request.authorization.split(' ', 2).last || '')
     login, api_key = credentials.split(/:/, 2)
-    DanbooruLogger.add_attributes("request.params", login: login)
+    DanbooruLogger.add_attributes("param", login: login)
     authenticate_api_key(login, api_key)
   end
 

config/danbooru_default_config.rb

@@ -547,6 +547,13 @@ module Danbooru
       # "redis://localhost:6379"
     end
 
+    # Optional. The URL of the Elastic APM server. Used for application performance monitoring.
+    #
+    # https://www.elastic.co/observability/application-performance-monitoring
+    def elastic_apm_server_url
+      # "http://localhost:8200"
+    end
+
     # True if the Winter Sale is active.
     def is_promotion?
       false

config/initializers/00_elastic_apm.rb

@@ -0,0 +1,10 @@
+if Danbooru.config.elastic_apm_server_url.present?
+  require "elastic_apm"
+
+  # https://www.elastic.co/guide/en/apm/agent/ruby/4.x/api.html#api-agent-start
+  # https://www.elastic.co/guide/en/apm/agent/ruby/4.x/configuration.html
+  ElasticAPM::Rails.start(
+    server_url: Danbooru.config.elastic_apm_server_url,
+    service_name: "Danbooru",
+  )
+end