(MAINT) Add optional API Request Logging

This was partially an exercise to use middleware, but also to enable
basic logging for the API by logging all the API calls to the logger.

lib/vmpooler.rb

@@ -84,6 +84,7 @@ module Vmpooler
     parsed_config[:config]['experimental_features'] = ENV['EXPERIMENTAL_FEATURES'] if ENV['EXPERIMENTAL_FEATURES']
     parsed_config[:config]['purge_unconfigured_folders'] = ENV['PURGE_UNCONFIGURED_FOLDERS'] if ENV['PURGE_UNCONFIGURED_FOLDERS']
     parsed_config[:config]['usage_stats'] = ENV['USAGE_STATS'] if ENV['USAGE_STATS']
+    parsed_config[:config]['request_logger'] = ENV['REQUEST_LOGGER'] if ENV['REQUEST_LOGGER']
 
     parsed_config[:redis] = parsed_config[:redis] || {}
     parsed_config[:redis]['server'] = ENV['REDIS_SERVER'] || parsed_config[:redis]['server'] || 'localhost'

lib/vmpooler/api.rb

@@ -9,7 +9,7 @@ module Vmpooler
     # Load dashboard components
     require 'vmpooler/dashboard'
 
-    def self.execute(torun, config, redis, metrics)
+    def self.execute(torun, config, redis, metrics, logger)
       self.settings.set :config, config
       self.settings.set :redis, redis unless redis.nil?
       self.settings.set :metrics, metrics
@@ -43,6 +43,9 @@ module Vmpooler
       end
 
       if torun.include? :api
+        # Enable API request logging only if required
+        use Vmpooler::API::RequestLogger, logger: logger if config[:config]['request_logger']
+
         use Vmpooler::Dashboard
         use Vmpooler::API::Dashboard
         use Vmpooler::API::Reroute

lib/vmpooler/api/request_logger.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Vmpooler
+  class API
+    class RequestLogger
+      attr_reader :app
+
+      def initialize(app, options = {})
+        @app = app
+        @logger = options[:logger]
+      end
+
+      def call(env)
+        status, headers, body = @app.call(env)
+        @logger.log('s', "[ ] API: Method: #{env['REQUEST_METHOD']}, Status: #{status}, Path: #{env['PATH_INFO']}, Body: #{body}")
+        [status, headers, body]
+      end
+    end
+  end
+end

lib/vmpooler/metrics/promstats/collector_middleware.rb

@@ -6,9 +6,10 @@
 #
 # The code was also failing Rubocop on PR check, so have addressed all the offenses.
 #
-# The method strip_ids_from_path has been adapted to add a match for hostnames in paths
-# to replace with a single ":hostname" string to avoid proliferation of stat lines for
-# each new vm hostname deleted, modified or otherwise queried.
+# The method strip_hostnames_from_path (originally strip_ids_from_path) has been adapted
+# to add a match for hostnames in paths # to replace with a single ":hostname" string to
+# avoid # proliferation of stat lines for # each new vm hostname deleted, modified or
+# otherwise queried.
 
 require 'benchmark'
 require 'prometheus/client'
@@ -91,12 +92,12 @@ module Vmpooler
           counter_labels = {
             code: code,
             method: env['REQUEST_METHOD'].downcase,
-            path: strip_ids_from_path(env['PATH_INFO'])
+            path: strip_hostnames_from_path(env['PATH_INFO'])
           }
 
           duration_labels = {
             method: env['REQUEST_METHOD'].downcase,
-            path: strip_ids_from_path(env['PATH_INFO'])
+            path: strip_hostnames_from_path(env['PATH_INFO'])
           }
 
           @requests.increment(labels: counter_labels)
@@ -105,10 +106,11 @@ module Vmpooler
           nil
         end
 
-        def strip_ids_from_path(path)
+        def strip_hostnames_from_path(path)
           # Custom for /vm path - so we just collect aggrate stats for all usage along this one
           # path. Custom counters are then added more specific endpoints in v1.rb
           # Since we aren't parsing UID/GIDs as in the original example, these are removed.
+          # Similarly, request IDs are also stripped from the /ondemand path.
           path
             .gsub(%r{/vm/.+$}, '/vm')
             .gsub(%r{/ondemand/.+$}, '/ondemand')