From 392ac363129279991be3f494a493c0b6d55a6ebb Mon Sep 17 00:00:00 2001
From: Denis Knauf <d.knauf@nfotex.com>
Date: Sun, 9 May 2021 14:39:21 +0200
Subject: [PATCH] Splitting Registry for action and process-statistics and
 clean up repositry.

config.yml was only an example, so name it as config.yml.example and
ignore any config.yml, that checkout could be used as local
project-directory without conflicts.

DnsblCollector will have singleton-behaviour like process configs and an
own Registry.  Config was loaded every request, yet.
There was one Registry, which was reused for every request.  Now every
request will use his own Registry.

Requests will get the content of both Registries.
---
 .gitignore                       |  5 ++
 config.ru                        |  8 ++-
 config.yml => config.yml.example |  3 +-
 dnsbl_exporter.rb                | 88 ++++++++++++++++++++------------
 4 files changed, 68 insertions(+), 36 deletions(-)
 create mode 100644 .gitignore
 rename config.yml => config.yml.example (96%)

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6e8bbf4
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+*.sw[pomnqrst]
+*.gem
+
+config.yml
+Gemfile.lock
diff --git a/config.ru b/config.ru
index 13d7500..1b244c3 100644
--- a/config.ru
+++ b/config.ru
@@ -1,6 +1,9 @@
+# vim: set noet sw=2 ts=2 sts=2:
 require 'rack'
-require './dnsbl_exporter'
+require_relative 'dnsbl_exporter'
+require 'yaml'
 
+DnsblCollector.load_config './config.yml'
 
 run lambda {|env|
   begin
@@ -16,7 +19,8 @@ run lambda {|env|
         end
       collector.collect target
       [200, {"Content-Type" => "text/plain"}, [
-        Prometheus::Client::Formats::Text.marshal( collector.prometheus)
+        Prometheus::Client::Formats::Text.marshal( collector.registry),
+        Prometheus::Client::Formats::Text.marshal( DnsblCollector.registry),
       ]]
     else
       [404, {"Content-Type" => "text/plain"}, ["Not found.\nYou want to try /metrics?\n"]]
diff --git a/config.yml b/config.yml.example
similarity index 96%
rename from config.yml
rename to config.yml.example
index 6be99f2..0c7b31a 100644
--- a/config.yml
+++ b/config.yml.example
@@ -1,7 +1,7 @@
 # vim: set et sw=2 ts=2 sts=2:
 ---
 resolver:
-  nameservers: 8.8.8.8
+  nameservers: '::1'
 blacklists:
 - all.s5h.net
 - b.barracudacentral.org
@@ -17,7 +17,6 @@ blacklists:
 - dnsbl-1.uceprotect.net
 - dnsbl-2.uceprotect.net
 - dnsbl-3.uceprotect.net
-- dnsbl.anticaptcha.net
 - dnsbl.dronebl.org
 - dnsbl.inps.de
 - dnsbl.sorbs.net
diff --git a/dnsbl_exporter.rb b/dnsbl_exporter.rb
index fba6bf5..31a7cf8 100644
--- a/dnsbl_exporter.rb
+++ b/dnsbl_exporter.rb
@@ -1,52 +1,76 @@
+# vim: set noet sw=2 ts=2 sts=2:
 require 'prometheus/client'
 require 'prometheus/client/formats/text'
 require 'net/dns'
-require 'yaml'
+require 'ostruct'
 
-class	DnsblCollector
-	attr_reader :lists, :prometheus, :configfile, :resolver, :metrics
+class DnsblCollector
+	class <<self
+		attr_reader :blacklists, :resolver, :registry
 
-	def initialize prometheus: nil, configfile: nil
-		@configfile = configfile || 'config.yml'
-		@prometheus = prometheus || Prometheus::Client.registry
-		%i[dnsbl_listed dnsbl_query_error].each {|m| @prometheus.unregister m }
-		@metrics = {
-			dnsbl_listed: @prometheus.gauge( :dnsbl_listed, 'IP listed currently on Blacklist'),
-			dnsbl_query_error: @prometheus.counter( :dnsbl_query_error, 'Errors while query for blacklist'),
-		}
-		load_config
+		def load_config file = nil
+			config = YAML.load_file file || './config.yml'
+			self.blacklists = config['blacklists']
+			self.resolver = config['resolver']
+		end
+
+		def blacklists= lists
+			@blacklists =
+				lists.map do |bl|
+					case bl
+					when String then {blacklist: bl}
+					when Hash then bl
+					else raise ConfigError, "Unexpected Element in blacklists: #{bl}"
+					end
+				end
+		end
+
+		def resolver= resolver_cnf
+			@resolver =
+				case resolver_cnf
+				when Net::DNS::Resolver then resolver_cnf
+				when Hash then Net::DNS::Resolver.new resolver_cnf
+				else
+					raise ConfigError, "DnsblCollector.resolver= expects a Net::DNS::Resolver or a resolver-config as Hash"
+				end
+		end
+
+		def registry= registry
+			@registry = registry
+			@registry.counter :dnsbl_query_error_count, docstring: 'Errors while query for blacklist', labels: %i[blacklist target]
+			@registry.counter :dnsbl_query_blacklist_duration_sum, docstring: 'Total duration for querieng this blacklist', labels: %i[blacklist]
+			@registry.counter :dnsbl_query_blacklist_count, docstring: 'Total count of queries this blacklist', labels: %i[blacklist]
+		end
 	end
 
-	def load_config
-		config = YAML.load_file @configfile
-		@resolver = config['resolver']
-		@lists =
-			config['blacklists'].map do |bl|
-				case bl
-				when String then {blacklist: bl}
-				when Hash then bl
-				else raise ConfigError, "Unexpected Element in blacklists: #{bl}"
-				end
-			end
+	self.registry = Prometheus::Client::Registry.new
+
+	attr_reader :lists, :registry, :configfile, :resolver, :metrics
+
+	def initialize registry: nil
+		@registry = registry || Prometheus::Client::Registry.new
+		@registry.gauge :dnsbl_listed, docstring: 'IP listed currently on Blacklist', labels: %i[blacklist target]
+		@metrics = OpenStruct.new @registry.instance_variable_get( :@metrics).merge( self.class.registry.instance_variable_get( :@metrics))
 	end
 
 	def collect ip
 		prefix = ip.send :_reverse
 		ip = ip.to_s
-		dns = Net::DNS::Resolver.new @resolver
-		todo = @lists.sort{|_|rand}
-		durs = {}
+		todo = self.class.blacklists.sort{|_|rand}
+		resolver = self.class.resolver
 		10.times.map do
 			Thread.new do
-				while bl = @lists.pop
-					b = Time.now
+				while bl = todo.pop
+					name, b = bl[:blacklist], Time.now
 					begin
-						r = dns.search( "#{prefix}.#{bl[:blacklist]}", Net::DNS::A).answer.empty?
-						@metrics[:dnsbl_listed].set( {blacklist: bl[:blacklist], target: ip}, r ? 0 : 1)
+						r = resolver.search( "#{prefix}.#{name}", Net::DNS::A).answer.empty?
+						@metrics.dnsbl_listed.set r ? 0 : 1, labels: {blacklist: name, target: ip}
 					rescue Net::DNS::Resolver::NoResponseError
-						@metrics[:dnsbl_query_error].increment( {blacklist: bl[:blacklist], target: ip})
+						@metrics.dnsbl_query_error_count.increment labels: {blacklist: name, target: ip}
 					end
-					durs[bl[:blacklist]] = Time.now-b
+					dur = Time.now-b
+					@metrics.dnsbl_query_blacklist_duration_sum.increment by: dur, labels: {blacklist: name}
+					@metrics.dnsbl_query_blacklist_count.increment labels: {blacklist: name}
 				end
 			end
 		end.each &:join