Merge pull request #1203 from pulibrary/health_endpoint

Add Health Endpoint

Gemfile

@@ -4,6 +4,7 @@ source "https://rubygems.org"
 
 gem "autoprefixer-rails"
 gem "ddtrace", "~> 0.54"
+gem "health-monitor-rails"
 gem "jquery-rails"
 gem "lograge"
 gem "logstash-event"
@@ -39,6 +40,7 @@ end
 
 group :test do
   gem "axe-core-rspec"
+  gem "webmock"
 end
 
 gem "blacklight", "7.31.0"

Gemfile.lock

@@ -148,6 +148,8 @@ GEM
       deep_merge (~> 1.2, >= 1.2.1)
       dry-validation (~> 1.0, >= 1.0.0)
     connection_pool (2.4.1)
+    crack (0.4.5)
+      rexml
     crass (1.0.6)
     database_cleaner (2.0.1)
       database_cleaner-active_record (~> 2.0.0)
@@ -320,6 +322,8 @@ GEM
       tilt (>= 1.2)
     hashdiff (1.0.1)
     hashie (5.0.0)
+    health-monitor-rails (11.3.0)
+      railties (>= 6.1)
     honeybadger (5.0.0)
     httpclient (2.8.3)
     i18n (1.14.1)
@@ -642,6 +646,10 @@ GEM
       nokogiri (~> 1.6)
       rubyzip (>= 1.3.0)
       selenium-webdriver (~> 4.0, < 4.11)
+    webmock (3.19.1)
+      addressable (>= 2.8.0)
+      crack (>= 0.3.2)
+      hashdiff (>= 0.4.0, < 2.0.0)
     webrick (1.7.0)
     websocket (1.2.10)
     websocket-driver (0.7.6)
@@ -683,6 +691,7 @@ DEPENDENCIES
   geoblacklight (= 3.7.0)
   geoblacklight_sidecar_images
   google-cloud-storage (~> 1.11)
+  health-monitor-rails
   honeybadger
   jquery-rails
   lograge
@@ -718,7 +727,8 @@ DEPENDENCIES
   vite_rails
   web-console
   webdrivers
+  webmock
   whenever
 
 BUNDLED WITH
-   2.3.18
+   2.4.10

app/checks/solr_status.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+class SolrStatus < HealthMonitor::Providers::Base
+  def check!
+    uri = Blacklight.default_index.connection.uri
+    status_uri = URI(uri.to_s.gsub(uri.path, "/solr/admin/cores?action=STATUS"))
+    req = Net::HTTP::Get.new(status_uri)
+    req.basic_auth(uri.user, uri.password) if uri.user && uri.password
+    response = Net::HTTP.start(uri.hostname, uri.port) { |http| http.request(req) }
+    json = JSON.parse(response.body)
+    raise "The solr has an invalid status #{status_uri}" if json["responseHeader"]["status"] != 0
+  end
+end

config/initializers/health_monitor.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+Rails.application.config.after_initialize do
+  HealthMonitor.configure do |config|
+    config.cache
+    config.redis unless Rails.env.test?
+
+    config.add_custom_provider(SolrStatus)
+
+    # Make this health check available at /health
+    config.path = :health
+
+    config.error_callback = proc do |e|
+      Rails.logger.error "Health check failed with: #{e.message}"
+      Honeybadger.notify(e)
+    end
+  end
+end

config/routes.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 Rails.application.routes.draw do
+  mount HealthMonitor::Engine, at: "/"
   concern :range_searchable, BlacklightRangeLimit::Routes::RangeSearchable.new
   mount Blacklight::Engine => "/"
   mount BlacklightAdvancedSearch::Engine => "/"

spec/requests/health_check_spec.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+require "rails_helper"
+
+RSpec.describe "Health Check", type: :request do
+  describe "GET /health" do
+    it "has a health check" do
+      get "/health.json"
+      expect(response).to be_successful
+    end
+
+    it "errors when a service is down" do
+      allow(Blacklight.default_index.connection).to receive(:uri).and_return(URI("http://example.com/bla"))
+      stub_request(:get, "http://example.com/solr/admin/cores?action=STATUS").to_return(
+        body: { responseHeader: { status: 500 } }.to_json, headers: { "Content-Type" => "text/json" }
+      )
+
+      get "/health.json"
+
+      expect(response).not_to be_successful
+      expect(response.status).to eq 503
+      solr_response = JSON.parse(response.body)["results"].find { |x| x["name"] == "SolrStatus" }
+      expect(solr_response["message"]).to start_with "The solr has an invalid status"
+    end
+  end
+end

spec/spec_helper.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 ENV["RACK_ENV"] = "test"
+require "webmock/rspec"
 require "simplecov"
 require "capybara/rspec"
 require "capybara-screenshot/rspec"
@@ -32,3 +33,9 @@
     mocks.verify_partial_doubles = true
   end
 end
+
+WebMock.disable_net_connect!(allow_localhost: true,
+                             net_http_connect_on_start: true,
+                             allow: ["chromedriver.storage.googleapis.com", "googlechromelabs.github.io",
+                                     "storage.googleapis.com",
+                                     "edgedl.me.gvt1.com"])