Implemented FileSystemFreeSpaceHealthCheck

src/main/java/nl/knaw/dans/lib/util/healthcheck/FileSystemFreeSpaceHealthCheck.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2021 DANS - Data Archiving and Networked Services (info@dans.knaw.nl)
+ *
+ * Licensed 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 nl.knaw.dans.lib.util.healthcheck;
+
+import com.codahale.metrics.health.HealthCheck;
+import io.dropwizard.util.DataSize;
+import lombok.AllArgsConstructor;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+/**
+ * A health check that verifies that the file system containing the given path has at least the given margin of free space.
+ */
+@AllArgsConstructor
+public class FileSystemFreeSpaceHealthCheck extends HealthCheck {
+    private final Path path;
+    private final DataSize margin;
+
+    @Override
+    protected Result check() throws Exception {
+        long freeSpace = Files.getFileStore(path).getUsableSpace();
+        long requiredSpace = margin.toBytes();
+
+        if (freeSpace < requiredSpace) {
+            return Result.unhealthy(String.format(
+                "Free space on file system containing %s is %d bytes, which is less than the required margin of %d bytes.",
+                path, freeSpace, requiredSpace
+            ));
+        }
+        return Result.healthy(String.format(
+            "Free space on file system containing %s is %d bytes, which is above the required margin of %d bytes.",
+            path, freeSpace, requiredSpace
+        ));
+    }
+
+    @Override
+    public String toString() {
+        return "FileSystemFreeSpaceHealthCheck{" +
+            "path=" + path +
+            ", margin=" + margin +
+            '}';
+    }
+}

src/test/java/nl/knaw/dans/lib/util/healthcheck/FileSystemFreeSpaceHealthCheckTest.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2021 DANS - Data Archiving and Networked Services (info@dans.knaw.nl)
+ *
+ * Licensed 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 nl.knaw.dans.lib.util.healthcheck;
+
+import com.codahale.metrics.health.HealthCheck;
+import io.dropwizard.util.DataSize;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+import org.mockito.Mockito;
+
+import java.nio.file.FileStore;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+public class FileSystemFreeSpaceHealthCheckTest {
+
+    @Test
+    public void healthy_when_free_space_is_above_required_margin() throws Exception {
+        // Given
+        Path path = Path.of("/any/path");
+        DataSize margin = DataSize.megabytes(100); // 100 MB
+        FileStore fileStore = mock(FileStore.class);
+        when(fileStore.getUsableSpace()).thenReturn(DataSize.gigabytes(1).toBytes()); // 1 GB free
+
+        try (MockedStatic<Files> filesMock = Mockito.mockStatic(Files.class)) {
+            filesMock.when(() -> Files.getFileStore(path)).thenReturn(fileStore);
+
+            FileSystemFreeSpaceHealthCheck healthCheck = new FileSystemFreeSpaceHealthCheck(path, margin);
+
+            // When
+            HealthCheck.Result result = healthCheck.check();
+
+            // Then
+            assertThat(result.isHealthy()).isTrue();
+            assertThat(result.getMessage())
+                .contains("Free space on file system containing")
+                .contains("is ")
+                .contains("which is above the required margin");
+        }
+    }
+
+    @Test
+    public void unhealthy_when_free_space_is_below_required_margin() throws Exception {
+        // Given
+        Path path = Path.of("/any/path");
+        DataSize margin = DataSize.gigabytes(2); // 2 GB required
+        FileStore fileStore = mock(FileStore.class);
+        when(fileStore.getUsableSpace()).thenReturn(DataSize.megabytes(500).toBytes()); // 500 MB free
+
+        try (MockedStatic<Files> filesMock = Mockito.mockStatic(Files.class)) {
+            filesMock.when(() -> Files.getFileStore(path)).thenReturn(fileStore);
+
+            FileSystemFreeSpaceHealthCheck healthCheck = new FileSystemFreeSpaceHealthCheck(path, margin);
+
+            // When
+            HealthCheck.Result result = healthCheck.check();
+
+            // Then
+            assertThat(result.isHealthy()).isFalse();
+            assertThat(result.getMessage())
+                .contains("Free space on file system containing")
+                .contains("is ")
+                .contains("which is less than the required margin");
+        }
+    }
+}