Provide shorthand to blocklist an IP

CHANGELOG.md

@@ -5,6 +5,7 @@ All notable changes to this project will be documented in this file.
 
 ### Added
 
+- Shorthand for blocking IP addresses `Rack::Attack.blocklist_ip("1.2.3.4")`
 - Throw helpful error message when using `allow2ban` but cache store is misconfigured ([#315](https://github.com/kickstarter/rack-attack/issues/315))
 - Throw helpful error message when using `fail2ban` but cache store is misconfigured ([#315](https://github.com/kickstarter/rack-attack/issues/315))
 

lib/rack/attack.rb

@@ -37,6 +37,12 @@ class Rack::Attack
       self.blocklists[name] = Blocklist.new(name, block)
     end
 
+    def blocklist_ip(ip)
+      @ip_blocklists ||= []
+      ip_blocklist_proc = lambda { |request| request.ip == ip }
+      @ip_blocklists << Blocklist.new(nil, ip_blocklist_proc)
+    end
+
     def blacklist(name, &block)
       warn "[DEPRECATION] 'Rack::Attack.blacklist' is deprecated.  Please use 'blocklist' instead."
       blocklist(name, &block)
@@ -77,9 +83,8 @@ class Rack::Attack
     end
 
     def blocklisted?(req)
-      blocklists.any? do |name, blocklist|
-        blocklist[req]
-      end
+      ip_blocklists.any? { |blocklist| blocklist.match?(req) } ||
+        blocklists.any? { |_name, blocklist| blocklist.match?(req) }
     end
 
     def blacklisted?(req)
@@ -109,6 +114,7 @@ class Rack::Attack
 
     def clear!
       @safelists, @blocklists, @throttles, @tracks = {}, {}, {}, {}
+      @ip_blocklists = []
     end
 
     def blacklisted_response=(res)
@@ -121,6 +127,11 @@ class Rack::Attack
       blocklisted_response
     end
 
+    private
+
+    def ip_blocklists
+      @ip_blocklists ||= []
+    end
   end
 
   # Set defaults

lib/rack/attack/check.rb

@@ -17,6 +17,7 @@ module Rack
         }
       end
 
+      alias_method :match?, :[]
     end
   end
 end

spec/acceptance/blocking_ip_spec.rb

@@ -0,0 +1,38 @@
+require_relative "../spec_helper"
+
+describe "Blocking an IP" do
+  before do
+    Rack::Attack.blocklist_ip("1.2.3.4")
+  end
+
+  it "forbids request if IP matches" do
+    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+
+    assert_equal 403, last_response.status
+  end
+
+  it "succeeds if IP doesn't match" do
+    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+
+    assert_equal 200, last_response.status
+  end
+
+  it "notifies when the request is blocked" do
+    notified = false
+    notification_type = nil
+
+    ActiveSupport::Notifications.subscribe("rack.attack") do |_name, _start, _finish, _id, request|
+      notified = true
+      notification_type = request.env["rack.attack.match_type"]
+    end
+
+    get "/", {}, "REMOTE_ADDR" => "5.6.7.8"
+
+    refute notified
+
+    get "/", {}, "REMOTE_ADDR" => "1.2.3.4"
+
+    assert notified
+    assert_equal :blocklist, notification_type
+  end
+end