Removing "leftovers" from the plugin template.

There were some `Rename*` files/classes, this commit is removing them.
However, this step was not straightforward.

TL;DR I had the keep the integration test in `test` folder and disabled
the testingConvention task. I also had to change test testPluginInstalled
a bit because the name of the plugin does no seem to be consistent and
in some cases it equals to a class name (upstream ticket will be opened).

Closes #190

Signed-off-by: Lukáš Vlček <[email protected]>

README.md

@@ -239,13 +239,15 @@ If you have doubts about the system requirements, please check the [CI.yml](.git
 
 ## Testing
 
-Project contains [integration tests](src/yamlRestTest/resources/rest-api-spec) implemented using
+Project contains:
+- [integration tests](src/yamlRestTest/resources/rest-api-spec) implemented using
 [rest layer](https://github.com/opensearch-project/OpenSearch/blob/main/TESTING.md#testing-the-rest-layer)
-framework.
+framework
+- [internal cluster tests](src/test)
 
 Complete test suite is run using:
 ```
-./gradlew clean assemble check
+./gradlew clean check
 ```
 
 To run individual integration rest test file use:

build.gradle

@@ -122,7 +122,7 @@ task integTest(type: RestIntegTestTask) {
 tasks.named("check").configure { dependsOn(integTest) }
 
 // Temporary disable task :testingConventions
-//testingConventions.enabled = false
+testingConventions.enabled = false
 
 testClusters.all {
     numberOfNodes = 2

src/test/java/org/opensearch/plugin/prometheus/PrometheusPluginIT.java

@@ -17,32 +17,56 @@
 package org.opensearch.plugin.prometheus;
 
 import com.carrotsearch.randomizedtesting.annotations.ThreadLeakScope;
+import org.apache.http.Header;
 import org.apache.http.util.EntityUtils;
+import org.opensearch.action.admin.cluster.node.info.NodeInfo;
+import org.opensearch.action.admin.cluster.node.info.NodesInfoResponse;
+import org.opensearch.action.admin.cluster.node.info.PluginsAndModules;
 import org.opensearch.client.Request;
 import org.opensearch.client.Response;
+import org.opensearch.client.RestClient;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.test.OpenSearchIntegTestCase;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
-
-import static org.hamcrest.Matchers.containsString;
 
 @ThreadLeakScope(ThreadLeakScope.Scope.NONE)
-@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE)
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.SUITE, numDataNodes = 2, numClientNodes = 0, supportsDedicatedMasters = false)
 public class PrometheusPluginIT extends OpenSearchIntegTestCase {
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return Collections.singletonList(RenamePlugin.class);
+        return Arrays.asList(PrometheusExporterPlugin.class);
     }
 
-    public void testPluginInstalled() throws IOException {
-        Response response = createRestClient().performRequest(new Request("GET", "/_cat/plugins"));
-        String body = EntityUtils.toString(response.getEntity());
+    /**
+     * Plugin must be installed on every cluster node.
+     */
+    public void testPluginInstalled() {
+        NodesInfoResponse response = client().admin().cluster().prepareNodesInfo().clear().all().get();
+        assertEquals(0, response.failures().size());
+        assertFalse(response.getNodes().isEmpty());
+        for (NodeInfo ni : response.getNodes()) {
+            assertNotNull(ni.getInfo(PluginsAndModules.class));
+            assertEquals(
+                    1,
+                    ni.getInfo(PluginsAndModules.class).getPluginInfos().stream().filter(
+                            pluginInfo -> pluginInfo.getClassname().endsWith("PrometheusExporterPlugin")
+                    ).count()
+            );
+        }
+    }
 
-        logger.info("response body: {}", body);
-        org.hamcrest.MatcherAssert.assertThat(body, containsString("prometheus-exporter"));
+    public void testPrometheusClientResponse() throws IOException {
+        RestClient rc = getRestClient();
+        logClusterState();
+        Response response = rc.performRequest(new Request("GET", "_prometheus/metrics"));
+        assertEquals(200, response.getStatusLine().getStatusCode());
+        assertEquals("text/plain; charset=UTF-8", response.getEntity().getContentType().getValue());
+        String body = EntityUtils.toString(response.getEntity(), StandardCharsets.UTF_8);
+        assertTrue(body.startsWith("# HELP"));
     }
 }