Add Regexp Targeting

CHANGELOG.md

@@ -4,6 +4,12 @@ Inspired by [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 Note: this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.20.0] - Unreleased
+### Added
+- Added regular expressions capabilities to targeting. See [README.md](README.md#Regexp-Targeting) for usage examples.
+### Fixed
+- Use `Pysch.safe_load_file` over `Pysch.load_file` with `Regexp` as only permitted class.
+
 ## [0.19.0] - 2021-07-09
 ### Fixed
 - Fixed a bug where accessing a setting that is a `Hash` defined across multiple file entries

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    process_settings (0.19.0)
+    process_settings (0.20.0.pre.2)
       activesupport (>= 4.2, < 7)
       json
       listen (~> 3.0)
@@ -26,11 +26,11 @@ GEM
     concurrent-ruby (1.1.7)
     diff-lcs (1.3)
     docile (1.4.0)
-    ffi (1.15.3)
+    ffi (1.15.5)
     i18n (1.8.5)
       concurrent-ruby (~> 1.0)
-    json (2.1.0)
-    listen (3.5.1)
+    json (2.6.1)
+    listen (3.7.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     method_source (0.9.0)
@@ -45,7 +45,7 @@ GEM
     psych (3.3.2)
     rainbow (3.0.0)
     rake (12.3.3)
-    rb-fsevent (0.11.0)
+    rb-fsevent (0.11.1)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     rspec (3.8.0)

README.md

@@ -164,6 +164,14 @@ target:
 ```
 This will be applied in any process that has (`service_name == "frontend"` OR `service_name == "auth"`) AND `datacenter == "AWS-US-EAST-1"`.
 
+### Regexp Targeting
+To provide a regular expression for targeting, use the ruby regex keyword `!ruby/regexp` followed by your regular expression. For example:
+```
+target:
+  service_name: !ruby/regexp /frontend-\d/
+```
+This will be applied in any process that has `service_name` that has `frontend-` followed with a number. As an example this will match `"frontend-1"`
+
 ### Precedence
 The settings YAML files are always combined in alphabetical order by file path. Later settings take precedence over the earlier ones.
 

lib/process_settings/target.rb

@@ -38,6 +38,12 @@ def with_static_context(target_value, static_context_hash)
           with_static_context_hash(target_value, static_context_hash)
         when true, false
           !target_value == !static_context_hash
+        when Regexp
+          if static_context_hash.is_a?(String)
+            static_context_hash.match?(target_value)
+          else
+            static_context_hash == target_value
+          end
         else
           target_value == static_context_hash
         end
@@ -90,6 +96,12 @@ def target_key_matches?(target_value, context_hash)
           end
         when true, false
           target_value
+        when Regexp
+          if context_hash.is_a?(String)
+            context_hash.match?(target_value)
+          else
+            context_hash == target_value
+          end
         else
           target_value == context_hash
         end

lib/process_settings/targeted_settings.rb

@@ -73,7 +73,7 @@ def from_array(settings_array, only_meta: false)
       end
 
       def from_file(file_path, only_meta: false)
-        json_doc = Psych.load_file(file_path)
+        json_doc = Psych.safe_load_file(file_path, permitted_classes: [Regexp])
         from_array(json_doc, only_meta: only_meta)
       end
     end

lib/process_settings/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module ProcessSettings
-  VERSION = '0.19.0'
+  VERSION = '0.20.0.pre.2'
 end

spec/bin/combine_process_settings_spec.rb

@@ -32,6 +32,11 @@
             max_recording_seconds: 600
             answer_odds: 100
             status_change_min_days:
+      - filename: regex_target.yml
+        target:
+          service: !ruby/regexp /frontend/
+        settings:
+          test_setting: 100
       - filename: stop_incoming_requests.yml
         target:
           region: east

spec/fixtures/production/combined_process_settings-20.yml

@@ -0,0 +1,47 @@
+---
+#
+# Don't edit this file directly! It was generated by combine_process_settings from the files in staging/settings/.
+#
+- filename: honeypot.yml
+  settings:
+    honeypot:
+      max_recording_seconds: 600
+      answer_odds: 100
+      status_change_min_days:
+- filename: regex_target.yml
+  target:
+    service: !ruby/regexp /frontend/
+  settings:
+    test_setting: 100
+- filename: telecom/log_level.yml
+  target:
+    app: telecom
+  settings:
+    logging:
+      level: debug
+- filename: telecom/stop_incoming_requests.yml
+  target:
+    app: telecom
+    region: west
+  settings:
+    incoming_requests: 0
+- filename: telecom/debug_sip_private_caller_id.yml
+  target:
+    app: telecom
+    region: west
+    caller_id:
+    - "+18053334444"
+    - "+12755554321"
+    - "+18052223344"
+  settings:
+    log_stream:
+      sip: caller_id_privacy
+- filename: cca/tech-1234_call_counts_drift_investigation.yml
+  target:
+    app: ccn
+  settings:
+    call_counts:
+      complete_sync_seconds: 60
+- meta:
+    version: 20
+    END: true

spec/fixtures/production/settings/regex_target.yml

@@ -0,0 +1,5 @@
+---
+target:
+  service: !ruby/regexp /frontend/
+settings:
+  test_setting: 100

spec/lib/process_settings/target_spec.rb

@@ -134,6 +134,81 @@
       expect(process_target.target_key_matches?(context_hash)).to be_truthy
       expect(process_target.target_key_matches?({})).to be_falsey
     end
+
+    describe "for regex matching" do
+      subject { process_target.target_key_matches?(context_hash) }
+      let(:process_target) { described_class.new(target_hash) }
+      let(:context_hash) do
+        {
+          'service' => service,
+          'region'  => 'east',
+          'cdr'     => { 'caller' => '+18056807000' }
+        }
+      end
+
+      context "with target value is a regular expression" do
+        let(:target_hash) { { 'service' => /telecom/ } }
+
+        context "when context hash value matches" do
+          let(:service) { 'telecom-1' }
+
+          it { is_expected.to be_truthy }
+        end
+
+        context "with an empty context hash" do
+          let(:context_hash) { {} }
+          it { is_expected.to be_falsey }
+        end
+
+        context "with a non-matching context value" do
+          let(:service) { 'tele' }
+          it { is_expected.to be_falsey }
+        end
+      end
+
+      context "when target value is a regex as a string" do
+        let(:target_hash) { { 'service' => '/telecom/' } }
+
+        context "when context hash value has the string but not the slash" do
+          let(:service) { 'telecom' }
+
+          it { is_expected.to be_falsey }
+        end
+
+        context "when context hash value exactly matches the string target value" do
+          let(:service) { '/telecom/' }
+          it { is_expected.to be_truthy }
+        end
+      end
+
+      context "when target value is valid and also has embedded slashes" do
+        let(:target_hash) { { 'service' => /tmp\/dir\/log/ } }
+
+        context "when context hash value matches the target" do
+          let(:service) { 'tmp/dir/log/service-log.txt' }
+          it { is_expected.to be_truthy }
+        end
+
+        context "when context hash only has whats between the embedded slashes" do
+          let(:service) { 'dir' }
+          it { is_expected.to be_falsey }
+        end
+      end
+
+      context "when context hash and target hash don't match keys" do
+        let(:context_hash) do
+          {
+            'service' => { 'name' => service },
+            'region'  => 'east',
+            'cdr'     => { 'caller' => '+18056807000' }
+          }
+        end
+        let(:target_hash) { { 'service' => /telecom/ } }
+        let(:service) { 'telecom-1' }
+
+        it { is_expected.to be_falsey }
+      end
+    end
   end
 
   describe "#with_static_context" do
@@ -333,6 +408,81 @@
         it { should eq(target_hash) }
       end
     end
+
+    describe "for regex matching" do
+      subject { process_target.with_static_context(context_hash).json_doc }
+      let(:process_target) { described_class.new(target_hash) }
+      let(:context_hash) do
+        {
+          'service' => service,
+          'region'  => 'east',
+          'cdr'     => { 'caller' => '+18056807000' }
+        }
+      end
+
+      context "with target value is a regular expression" do
+        let(:target_hash) { { 'service' => /telecom/ } }
+
+        context "when context hash value matches" do
+          let(:service) { 'telecom-1' }
+
+          it { is_expected.to be_truthy }
+        end
+
+        context "with an empty context hash" do
+          let(:context_hash) { {} }
+          it { is_expected.to eq(target_hash) }
+        end
+
+        context "with a non-matching context value" do
+          let(:service) { 'tele' }
+          it { is_expected.to be_falsey }
+        end
+      end
+
+      context "when target value is a regex as a string" do
+        let(:target_hash) { { 'service' => '/telecom/' } }
+
+        context "when context hash value has the string but not the slash" do
+          let(:service) { 'telecom' }
+
+          it { is_expected.to be_falsey }
+        end
+
+        context "when context hash value exactly matches the string target value" do
+          let(:service) { '/telecom/' }
+          it { is_expected.to be_truthy }
+        end
+      end
+
+      context "when target value is valid and also has embedded slashes" do
+        let(:target_hash) { { 'service' => /tmp\/dir\/log/ } }
+
+        context "when context hash value matches the target" do
+          let(:service) { 'tmp/dir/log/service-log.txt' }
+          it { is_expected.to be_truthy }
+        end
+
+        context "when context hash only has whats between the embedded slashes" do
+          let(:service) { 'dir' }
+          it { is_expected.to be_falsey }
+        end
+      end
+
+      context "when context hash and target hash don't match keys" do
+        let(:context_hash) do
+          {
+            'service' => { 'name' => service },
+            'region'  => 'east',
+            'cdr'     => { 'caller' => '+18056807000' }
+          }
+        end
+        let(:target_hash) { { 'service' => /telecom/ } }
+        let(:service) { 'telecom-1' }
+
+        it { is_expected.to be_falsey }
+      end
+    end
   end
 
   describe "class methods" do

spec/lib/process_settings/targeted_settings_spec.rb

@@ -78,6 +78,21 @@
     end
   end
 
+  context "with ruby's special regular expression keyword" do
+    let(:file_path) { File.expand_path("../../fixtures/production/combined_process_settings-20.yml", __dir__) }
+
+    describe ".from_file" do
+      it "reads from yaml file and properly converts the special keyword and expression in the file into a ruby Regexp object" do
+        targeted_settings = described_class.from_file(file_path)
+
+        regex_target_setting = targeted_settings.targeted_settings_array[1]
+        expect(regex_target_setting.filename).to eq("regex_target.yml")
+        expect(regex_target_setting.target.json_doc).to eq({ "service" => /frontend/ })
+        expect(regex_target_setting.settings.json_doc).to eq({ "test_setting" => 100 })
+      end
+    end
+  end
+
   describe ".from_array" do
     it "delegates" do
       target_and_settings = described_class.from_array(TARGETED_SETTINGS)