Merge pull request #86 from psu-libraries/healthchecks

version and solr checks

Gemfile

@@ -20,6 +20,7 @@ gem 'importmap-rails'
 gem 'jbuilder'
 gem 'jquery-rails'
 gem 'mysql2'
+gem 'okcomputer'
 gem 'puma', '~> 5.0'
 gem 'rails', '~> 7.0.3'
 gem 'redis', '~> 4.0'
@@ -44,6 +45,7 @@ group :test do
   gem 'rspec-rails'
   gem 'selenium-webdriver'
   gem 'webdrivers'
+  gem 'webmock'
 end
 
 group :development, :test do

Gemfile.lock

@@ -117,6 +117,8 @@ GEM
     coderay (1.1.3)
     colorize (0.8.1)
     concurrent-ruby (1.1.10)
+    crack (0.4.5)
+      rexml
     crass (1.0.6)
     deprecation (1.1.0)
       activesupport
@@ -242,6 +244,7 @@ GEM
       builder (>= 3.1.0)
       faraday (< 3)
       faraday-follow_redirects (>= 0.3.0, < 2)
+    okcomputer (1.18.4)
     orm_adapter (0.5.0)
     ostruct (0.5.5)
     parallel (1.22.1)
@@ -419,6 +422,10 @@ GEM
       nokogiri (~> 1.6)
       rubyzip (>= 1.3.0)
       selenium-webdriver (~> 4.0)
+    webmock (3.14.0)
+      addressable (>= 2.8.0)
+      crack (>= 0.3.2)
+      hashdiff (>= 0.4.0, < 2.0.0)
     websocket (1.2.9)
     websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
@@ -451,6 +458,7 @@ DEPENDENCIES
   jquery-rails
   mysql2
   niftany (>= 0.10)
+  okcomputer
   pry-byebug
   puma (~> 5.0)
   rails (~> 7.0.3)
@@ -469,6 +477,7 @@ DEPENDENCIES
   tzinfo-data
   web-console
   webdrivers
+  webmock
 
 RUBY VERSION
    ruby 3.1.2p20

config/application.rb

@@ -12,6 +12,7 @@ module EtdaExplore
   class Application < Rails::Application
     require 'etda_explore/solr_config'
     require 'overrides/resumption_token'
+    require 'healthchecks'
 
     config.solr = EtdaExplore::SolrConfig.new
 

config/initializers/okcomputer.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+OkComputer.mount_at = false
+
+OkComputer::Registry.register(
+  'version',
+  HealthChecks::VersionCheck.new
+)
+
+OkComputer::Registry.register(
+  'solr',
+  HealthChecks::SolrCheck.new
+)
+
+OkComputer.make_optional %w(version)

config/routes.rb

@@ -6,6 +6,8 @@
   concern :searchable, Blacklight::Routes::Searchable.new
   concern :oai_provider, BlacklightOaiProvider::Routes.new
 
+  mount OkComputer::Engine, at: '/health'
+
   authenticate :user do
     get '/login', to: 'application#login', as: :login
   end

lib/healthchecks.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+module Healthchecks
+  require 'healthchecks/version_check'
+  require 'healthchecks/solr_check'
+end

lib/healthchecks/solr_check.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module HealthChecks
+  class SolrCheck < OkComputer::Check
+    def check
+      solr = RSolr.connect(url: Rails.configuration.solr.query_url)
+      resp = solr.get('admin/ping')
+      status = resp&.dig('status')
+      zk_connected = resp&.dig('responseHeader')&.dig('zkConnected')
+      @message = Hash.new
+      @message['zkConnected'] = zk_connected
+      @message['status'] = status
+      mark_message(@message)
+      mark_failure unless status == 'OK'
+      mark_failure unless zk_connected == true
+    end
+  end
+end

lib/healthchecks/version_check.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+module HealthChecks
+  class VersionCheck < OkComputer::Check
+    def check
+      version = ENV.fetch('APP_VERSION', 'unknown')
+      mark_message version.to_s
+    end
+  end
+end

spec/lib/healthchecks/solr_check_spec.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe HealthChecks::SolrCheck do
+  describe '#check' do
+    before(:all) do
+      WebMock.disable_net_connect!
+    end
+
+    after(:all) do
+      WebMock.enable_net_connect!
+    end
+
+    context 'when we can connect to solr' do
+      before do
+        stub_request(:get, /admin\/ping/)
+          .to_return(status: 200, body: {
+            responseHeader: {
+              zkConnected: true
+            },
+            status: 'OK'
+          }.to_json)
+      end
+
+      it 'returns no failure' do
+        hc = described_class.new
+        hc.check
+        expect(hc.failure_occurred).to be_nil
+      end
+    end
+
+    context 'when zk is not connected' do
+      before do
+        stub_request(:get, /admin\/ping/)
+          .to_return(status: 200, body: {
+            responseHeader: {
+              zkConnected: false
+            },
+            status: 'OK'
+          }.to_json)
+      end
+
+      it 'returns a failure' do
+        hc = described_class.new
+        hc.check
+        expect(hc.failure_occurred).to be true
+      end
+    end
+  end
+end

spec/lib/healthchecks/version_check_spec.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe HealthChecks::VersionCheck do
+  describe '#check' do
+    context 'when version' do
+      before do
+        ENV['APP_VERSION'] = '3'
+      end
+
+      it 'returns no failure' do
+        hc = described_class.new
+        hc.check
+        expect(hc.failure_occurred).to be_nil
+      end
+
+      it 'writes a message' do
+        hc = described_class.new
+        hc.check
+        expect(hc.message).to eq('3')
+      end
+    end
+
+    context 'when no version' do
+      before do
+        ENV['APP_VERSION'] = nil
+      end
+
+      it 'writes unknown' do
+        hc = described_class.new
+        hc.check
+        expect(hc.message).to eq('unknown')
+      end
+    end
+  end
+end

spec/spec_helper.rb

@@ -1,7 +1,9 @@
 # frozen_string_literal: true
 
 require 'simplecov'
+require 'webmock/rspec'
 SimpleCov.start
+WebMock.allow_net_connect!
 
 # This file was generated by the `rails generate rspec:install` command. Conventionally, all
 # specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.