Add solr monitor

Gemfile

@@ -24,5 +24,6 @@ gem 'sidekiq', '>= 3.0'
 gem 'spork'
 gem 'sqlite3', '~> 1.3'
 gem 'timecop'
+gem 'webmock'
 
 gemspec

README.md

@@ -176,6 +176,7 @@ The following services are currently supported:
 * Sidekiq
 * Resque
 * Delayed Job
+* Solr
 
 ## Configuration
 
@@ -312,6 +313,10 @@ Please note that `url` or `connection` can't be used at the same time.
 
 * `queue_size`: the size (maximum) of a queue which is considered unhealthy (the default is 100).
 
+### Solr
+
+* `url`: the URL used to connect to your Solr instance - must be a string. You can also use `url` to explicitly configure authentication (e.g., `'https://user:[email protected]:8983/'`)
+
 ### Adding a Custom Provider
 
 It's also possible to add custom health check providers suited for your needs (of course, it's highly appreciated and encouraged if you'd contribute useful providers to the project).

gemfiles/rails_6.1.gemfile

@@ -27,5 +27,6 @@ gem 'sidekiq', '>= 3.0'
 gem 'spork'
 gem 'sqlite3', '~> 1.3'
 gem 'timecop'
+gem 'webmock'
 
 gemspec path: '../'

gemfiles/rails_7.1_.gemfile

@@ -27,5 +27,6 @@ gem 'sidekiq', '>= 3.0'
 gem 'spork'
 gem 'sqlite3', '~> 1.3'
 gem 'timecop'
+gem 'webmock'
 
 gemspec path: '../'

lib/health_monitor/configuration.rb

@@ -2,7 +2,7 @@
 
 module HealthMonitor
   class Configuration
-    PROVIDERS = %i[cache database delayed_job redis resque sidekiq].freeze
+    PROVIDERS = %i[cache database delayed_job redis resque sidekiq solr].freeze
 
     attr_accessor :basic_auth_credentials,
                   :environment_variables,

lib/health_monitor/providers/solr.rb

@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+require 'health_monitor/providers/base'
+
+module HealthMonitor
+  module Providers
+    class SolrException < StandardError; end
+
+    class Solr < Base
+      class Configuration < Base::Configuration
+        DEFAULT_URL = nil
+        attr_accessor :url
+
+        def initialize(provider)
+          super(provider)
+
+          @url = DEFAULT_URL
+        end
+      end
+
+      def check!
+        check_solr_connection!
+      rescue Exception => e
+        raise SolrException.new(e.message)
+      end
+
+      private
+
+      def configuration_class
+        ::HealthMonitor::Providers::Solr::Configuration
+      end
+
+      def check_solr_connection!
+        json = JSON.parse(solr_response.body)
+        raise "The solr has an invalid status #{status_uri}" if json['responseHeader']['status'] != 0
+      end
+
+      def status_uri
+        @status_uri ||= begin
+          uri = URI(configuration.url)
+          uri.path = '/solr/admin/cores'
+          uri.query = 'action=STATUS'
+          uri
+        end
+      end
+
+      def solr_request
+        @solr_request ||= begin
+          req = Net::HTTP::Get.new(status_uri)
+          req.basic_auth(status_uri.user, status_uri.password) if status_uri.user && status_uri.password
+          req
+        end
+      end
+
+      def solr_response
+        Net::HTTP.start(status_uri.hostname, status_uri.port) { |http| http.request(solr_request) }
+      end
+    end
+  end
+end

spec/lib/health_monitor/providers/solr_spec.rb

@@ -0,0 +1,121 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe HealthMonitor::Providers::Solr do
+  subject { described_class.new }
+
+  context 'with defaults' do
+    it { expect(subject.configuration.name).to eq('Solr') }
+    it { expect(subject.configuration.url).to eq(HealthMonitor::Providers::Solr::Configuration::DEFAULT_URL) }
+  end
+
+  describe '#name' do
+    it { expect(subject.name).to eq('Solr') }
+  end
+
+  describe '#check!' do
+    let(:solr_url_config) { 'http://www.example-solr.com:8983' }
+
+    before do
+      subject.request = test_request
+      subject.configure do |config|
+        config.url = solr_url_config
+      end
+      Providers.stub_solr
+    end
+
+    context 'with a standard connection' do
+      it 'checks against the configured solr url' do
+        subject.check!
+        expect(Providers.stub_solr).to have_been_requested
+      end
+
+      it 'succesfully checks' do
+        expect {
+          subject.check!
+        }.not_to raise_error
+      end
+
+      context 'when failing' do
+        before do
+          Providers.stub_solr_failure
+        end
+
+        it 'fails check!' do
+          expect {
+            subject.check!
+          }.to raise_error(HealthMonitor::Providers::SolrException)
+        end
+
+        it 'checks against the configured solr url' do
+          expect {
+            subject.check!
+          }.to raise_error(HealthMonitor::Providers::SolrException)
+          expect(Providers.stub_solr_failure).to have_been_requested
+        end
+      end
+    end
+
+    context 'with a configured url that includes a path' do
+      let(:solr_url_config) { 'http://www.example-solr.com:8983/solr/blacklight-core-development' }
+
+      it 'checks against the configured solr url' do
+        subject.check!
+        expect(Providers.stub_solr).to have_been_requested
+      end
+    end
+
+    context 'with a connection with authentication' do
+      let(:solr_url_config) { 'http://solr:SolrRocks@localhost:8888' }
+
+      before { Providers.stub_solr_with_auth }
+
+      it 'checks against the configured solr url' do
+        subject.check!
+        expect(Providers.stub_solr_with_auth).to have_been_requested
+      end
+
+      it 'succesfully checks' do
+        expect {
+          subject.check!
+        }.not_to raise_error
+      end
+
+      context 'when failing' do
+        before do
+          Providers.stub_solr_failure_with_auth
+        end
+
+        it 'fails check!' do
+          expect {
+            subject.check!
+          }.to raise_error(HealthMonitor::Providers::SolrException)
+        end
+
+        it 'checks against the configured solr url' do
+          expect {
+            subject.check!
+          }.to raise_error(HealthMonitor::Providers::SolrException)
+          expect(Providers.stub_solr_failure_with_auth).to have_been_requested
+        end
+      end
+    end
+  end
+
+  describe '#configure' do
+    before do
+      subject.configure
+    end
+
+    let(:url) { 'solr://user:[email protected]:8983/' }
+
+    it 'url can be configured' do
+      expect {
+        subject.configure do |config|
+          config.url = url
+        end
+      }.to change { subject.configuration.url }.to(url)
+    end
+  end
+end

spec/spec_helper.rb

@@ -17,6 +17,7 @@
   require 'timecop'
   require 'mock_redis'
   require 'sidekiq/testing'
+  require 'webmock/rspec'
 
   Dir[File.expand_path('../lib/**/*.rb', __dir__)].sort.each { |f| require f }
   Dir[File.expand_path('support/**/*.rb', __dir__)].sort.each { |f| require f }

spec/support/providers.rb

@@ -90,4 +90,28 @@ def stub_sidekiq_over_retry_limit_failure
     allow(retry_set).to receive(:select).and_return([item: { retry_count: retry_count }])
     allow(Sidekiq::RetrySet).to receive(:new).and_return(retry_set)
   end
+
+  def stub_solr
+    WebMock.stub_request(:get, 'http://www.example-solr.com:8983/solr/admin/cores?action=STATUS').to_return(
+      body: { responseHeader: { status: 0 } }.to_json, headers: { 'Content-Type' => 'text/json' }
+    )
+  end
+
+  def stub_solr_failure
+    WebMock.stub_request(:get, 'http://www.example-solr.com:8983/solr/admin/cores?action=STATUS').to_return(
+      body: { responseHeader: { status: 500 } }.to_json, headers: { 'Content-Type' => 'text/json' }
+    )
+  end
+
+  def stub_solr_with_auth
+    WebMock.stub_request(:get, 'http://localhost:8888/solr/admin/cores?action=STATUS')
+           .with(headers: { 'Authorization' => 'Basic c29scjpTb2xyUm9ja3M=', 'Host' => 'localhost:8888' })
+           .to_return(body: { responseHeader: { status: 0 } }.to_json, headers: { 'Content-Type' => 'text/json' })
+  end
+
+  def stub_solr_failure_with_auth
+    WebMock.stub_request(:get, 'http://localhost:8888/solr/admin/cores?action=STATUS')
+           .with(headers: { 'Authorization' => 'Basic c29scjpTb2xyUm9ja3M=', 'Host' => 'localhost:8888' })
+           .to_return(body: { responseHeader: { status: 500 } }.to_json, headers: { 'Content-Type' => 'text/json' })
+  end
 end