Don't pass JAVA_HOME environment variable to OpenSearch process (#15166)

The OpenSearch process should use its bundled JVM version.

data-node/src/test/java/org/graylog/datanode/management/CommandLineProcessTest.java

@@ -21,13 +21,16 @@ import com.github.rholder.retry.Retryer;
 import com.github.rholder.retry.RetryerBuilder;
 import com.github.rholder.retry.StopStrategies;
 import com.github.rholder.retry.WaitStrategies;
+import org.apache.commons.exec.CommandLine;
 import org.apache.commons.exec.ExecuteException;
 import org.assertj.core.api.Assertions;
+import org.graylog.datanode.ProcessProvidingExecutor;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.File;
 import java.io.IOException;
 import java.net.URISyntaxException;
 import java.net.URL;
@@ -37,6 +40,7 @@ import java.nio.file.attribute.PosixFilePermissions;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
@@ -89,7 +93,14 @@ class CommandLineProcessTest {
                 LOG.info("On process failed:", e);
             }
         };
-        final CommandLineProcess process = new CommandLineProcess(binPath, Collections.emptyList(), listener);
+        final TestExecutor testExecutor = new TestExecutor();
+        final CommandLineProcess process = new CommandLineProcess(
+                binPath,
+                Collections.emptyList(),
+                listener,
+                () -> testExecutor,
+                () -> Map.of("USER", "test", "JAVA_HOME", "/path/to/jre")
+        );
         process.start();
 
         waitTillLogsAreAvailable(stdout, 3);
@@ -106,6 +117,8 @@ class CommandLineProcessTest {
                 .hasSize(1)
                 .contains("This message goes to stderr");
 
+        Assertions.assertThat(testExecutor.getEnvironment())
+                .doesNotContainKey("JAVA_HOME");
     }
 
     private void waitTillLogsAreAvailable(List<String> logs, int expectedLinesCount) throws ExecutionException, RetryException {
@@ -155,4 +168,21 @@ class CommandLineProcessTest {
 
         Assertions.assertThat(exitCode).isEqualTo(143);
     }
+
+    /**
+     * Implementation that allows access to the environment argument.
+     */
+    private static class TestExecutor extends ProcessProvidingExecutor {
+        private Map<String, String> environment = Map.of();
+
+        @Override
+        protected Process launch(CommandLine command, Map<String, String> env, File dir) throws IOException {
+            this.environment = env;
+            return super.launch(command, env, dir);
+        }
+
+        public Map<String, String> getEnvironment() {
+            return environment;
+        }
+    }
 }