Fix broken detection of mvnd home on alpine linux (fixes #849) (#848)

* Fix for musl dynamic loader
* Add caching for mvnd.home and java.home
* Add IT for alpine linux

integration-tests/pom.xml

@@ -94,6 +94,18 @@
       <artifactId>commons-compress</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.testcontainers</groupId>
+      <artifactId>testcontainers</artifactId>
+      <version>1.18.1</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.testcontainers</groupId>
+      <artifactId>junit-jupiter</artifactId>
+      <version>1.18.1</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

integration-tests/src/test/java/org/mvndaemon/mvnd/it/AlpineLinuxNativeIT.java

@@ -0,0 +1,70 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.mvndaemon.mvnd.it;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestInstance;
+import org.junit.jupiter.api.condition.DisabledOnOs;
+import org.junit.jupiter.api.condition.OS;
+import org.testcontainers.containers.GenericContainer;
+import org.testcontainers.images.builder.ImageFromDockerfile;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+@Testcontainers(disabledWithoutDocker = true)
+public class AlpineLinuxNativeIT {
+
+    private ImageFromDockerfile image;
+    private String mvndHome;
+
+    @BeforeAll
+    void createImage() {
+        image = new ImageFromDockerfile()
+                .withDockerfileFromBuilder(builder -> builder.from("bellsoft/liberica-openjdk-alpine-musl:latest")
+                        .run("apk add gcompat")
+                        .build());
+        mvndHome = System.getProperty("mvnd.home");
+        if (mvndHome == null) {
+            throw new IllegalStateException("System property mnvd.home is undefined");
+        }
+    }
+
+    @Test
+    @DisabledOnOs(OS.WINDOWS)
+    void testAlpineJvm() throws Exception {
+        String logs;
+        try (GenericContainer<?> alpine = new GenericContainer<>(image)
+                .withFileSystemBind(mvndHome, "/mvnd")
+                .withCommand(isNative() ? "/mvnd/bin/mvnd" : "/mvnd/bin/mvnd.sh", "-v")) {
+            alpine.start();
+            while (alpine.isRunning()) {
+                Thread.sleep(100);
+            }
+            logs = alpine.getLogs();
+        }
+        assertTrue(logs.contains("Apache Maven Daemon"), logs);
+    }
+
+    protected boolean isNative() {
+        return true;
+    }
+}

integration-tests/src/test/java/org/mvndaemon/mvnd/it/AlpineLinuxTest.java

@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.mvndaemon.mvnd.it;
+
+import org.junit.jupiter.api.TestInstance;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+@Testcontainers(disabledWithoutDocker = true)
+public class AlpineLinuxTest extends AlpineLinuxNativeIT {
+
+    @Override
+    protected boolean isNative() {
+        return false;
+    }
+}