add license check as a criteria of connection check (logstash-plugins#1035)

This commit fixes post-register action when Elasticsearch status change from unhealthy to healthy
The connection is classified as alive when it passed `/` and `/_license` check

Fixed: logstash-plugins#1034

Author: kaisecheng

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 11.0.5
+ - Fixed running post-register action when Elasticsearch status change from unhealthy to healthy [#1035](https://github.com/logstash-plugins/logstash-output-elasticsearch/pull/1035)
+
 ## 11.0.4
  - [DOC] Clarify that `http_compression` applies to _requests_, and remove noise about _response_ decompression [#1000](https://github.com/logstash-plugins/logstash-output-elasticsearch/pull/1000)
 

lib/logstash/outputs/elasticsearch/http_client.rb

@@ -92,6 +92,10 @@ def maximum_seen_major_version
       @pool.maximum_seen_major_version
     end
 
+    def alive_urls_count
+      @pool.alive_urls_count
+    end
+
     def bulk(actions)
       @action_count ||= 0
       @action_count += actions.size

lib/logstash/plugin_mixins/elasticsearch/common.rb

@@ -128,8 +128,12 @@ def maximum_seen_major_version
       client.maximum_seen_major_version
     end
 
+    def alive_urls_count
+      client.alive_urls_count
+    end
+
     def successful_connection?
-      !!maximum_seen_major_version
+      !!maximum_seen_major_version && alive_urls_count > 0
     end
 
     # launch a thread that waits for an initial successful connection to the ES cluster to call the given block

logstash-output-elasticsearch.gemspec

@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name            = 'logstash-output-elasticsearch'
-  s.version         = '11.0.4'
+  s.version         = '11.0.5'
 
   s.licenses        = ['apache-2.0']
   s.summary         = "Stores logs in Elasticsearch"

spec/integration/outputs/no_es_on_startup_spec.rb

@@ -55,4 +55,18 @@
     expect(r).to have_hits(2)
   end
 
+  it 'should get cluster_uuid when Elasticsearch recovers from license check failure' do
+    allow_any_instance_of(LogStash::Outputs::ElasticSearch::HttpClient::Pool).to receive(:get_license).with(instance_of(LogStash::Util::SafeURI)).and_raise(::LogStash::Outputs::ElasticSearch::HttpClient::Pool::HostUnreachableError.new(StandardError.new, "big fail"))
+    subject.register
+    Thread.new do
+      sleep 4
+      allow_any_instance_of(LogStash::Outputs::ElasticSearch::HttpClient::Pool).to receive(:get_license).with(instance_of(LogStash::Util::SafeURI)).and_call_original
+    end
+    subject.multi_receive([event1, event2])
+    @es.indices.refresh
+    r = @es.search(index: 'logstash-*')
+    expect(r).to have_hits(2)
+    expect(subject.plugin_metadata.get(:cluster_uuid)).not_to be_empty
+    expect(subject.plugin_metadata.get(:cluster_uuid)).not_to eq("_na_")
+  end if ESHelper.es_version_satisfies?(">=7")
 end

spec/unit/outputs/elasticsearch_spec.rb

@@ -934,6 +934,7 @@
       allow(subject).to receive(:last_es_version).and_return es_version
       # make successful_connection? return true:
       allow(subject).to receive(:maximum_seen_major_version).and_return Integer(es_version.split('.').first)
+      allow(subject).to receive(:alive_urls_count).and_return Integer(1)
       allow(subject).to receive(:stop_after_successful_connection_thread)
     end
 

spec/unit/outputs/error_whitelist_spec.rb

@@ -12,6 +12,7 @@
   before :each do
     allow(subject.logger).to receive(:warn)
     allow(subject).to receive(:maximum_seen_major_version).and_return(0)
+    allow(subject).to receive(:alive_urls_count).and_return(1)
     allow(subject).to receive(:finish_register)
 
     subject.register