From d51b306731c367818be4b9e7bc1869c109376b61 Mon Sep 17 00:00:00 2001
From: Pierre Villard <pierre.villard.fr@gmail.com>
Date: Mon, 18 Nov 2024 17:58:42 +0100
Subject: [PATCH] NIFI-14005  Add processor GetFileResource processor

This closes #9519

Signed-off-by: Lucas Ottersbach <ottersbach@apache.org>
---
 .../processors/standard/GetFileResource.java  | 150 ++++++++++++++++++
 .../org.apache.nifi.processor.Processor       |   1 +
 .../standard/TestGetFileResource.java         |  59 +++++++
 3 files changed, 210 insertions(+)
 create mode 100644 nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/GetFileResource.java
 create mode 100644 nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/test/java/org/apache/nifi/processors/standard/TestGetFileResource.java

diff --git a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/GetFileResource.java b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/GetFileResource.java
new file mode 100644
index 0000000000..e04029621e
--- /dev/null
+++ b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/GetFileResource.java
@@ -0,0 +1,150 @@
+/*
+ * 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.apache.nifi.processors.standard;
+
+import org.apache.nifi.annotation.behavior.DynamicProperty;
+import org.apache.nifi.annotation.behavior.InputRequirement;
+import org.apache.nifi.annotation.behavior.InputRequirement.Requirement;
+import org.apache.nifi.annotation.behavior.Restricted;
+import org.apache.nifi.annotation.behavior.Restriction;
+import org.apache.nifi.annotation.behavior.WritesAttribute;
+import org.apache.nifi.annotation.behavior.WritesAttributes;
+import org.apache.nifi.annotation.configuration.DefaultSchedule;
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.components.RequiredPermission;
+import org.apache.nifi.components.resource.ResourceCardinality;
+import org.apache.nifi.components.resource.ResourceType;
+import org.apache.nifi.expression.AttributeExpression;
+import org.apache.nifi.expression.ExpressionLanguageScope;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.flowfile.attributes.CoreAttributes;
+import org.apache.nifi.processor.AbstractProcessor;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.processor.util.StandardValidators;
+import org.apache.nifi.scheduling.SchedulingStrategy;
+import org.apache.nifi.stream.io.StreamUtils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+@Tags({ "test", "file", "generate", "load" })
+@InputRequirement(Requirement.INPUT_FORBIDDEN)
+@CapabilityDescription("""
+        This processor creates FlowFiles with the content of the configured File Resource. GetFileResource
+        is useful for load testing, configuration, and simulation.
+        """)
+@DynamicProperty(
+        name = "Generated FlowFile attribute name", value = "Generated FlowFile attribute value", expressionLanguageScope = ExpressionLanguageScope.ENVIRONMENT,
+        description = "Specifies an attribute on generated FlowFiles defined by the Dynamic Property's key and value."
+)
+@WritesAttributes(
+    {
+            @WritesAttribute(attribute = "mime.type", description = "Sets the MIME type of the output if the 'MIME Type' property is set"),
+            @WritesAttribute(attribute = "Dynamic property key", description = "Value for the corresponding dynamic property, if any is set")
+    }
+)
+@DefaultSchedule(strategy = SchedulingStrategy.TIMER_DRIVEN, period = "1 min")
+@Restricted(
+        restrictions = {
+                @Restriction(requiredPermission = RequiredPermission.READ_FILESYSTEM, explanation = "Provides operator the ability to read from any file that NiFi has access to."),
+                @Restriction(requiredPermission = RequiredPermission.REFERENCE_REMOTE_RESOURCES, explanation = "File Resource can reference resources over HTTP/HTTPS")
+        }
+)
+public class GetFileResource extends AbstractProcessor {
+
+    public static final PropertyDescriptor FILE_RESOURCE = new PropertyDescriptor.Builder()
+            .name("File Resource")
+            .description("Location of the File Resource (Local File or URL). This file will be used as content of the generated FlowFiles.")
+            .required(true)
+            .identifiesExternalResource(ResourceCardinality.SINGLE, ResourceType.FILE, ResourceType.URL)
+            .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+            .build();
+    public static final PropertyDescriptor MIME_TYPE = new PropertyDescriptor.Builder()
+            .name("MIME Type")
+            .description("Specifies the value to set for the [mime.type] attribute.")
+            .required(false)
+            .addValidator(StandardValidators.NON_EMPTY_VALIDATOR)
+            .build();
+
+    private static final List<PropertyDescriptor> PROPERTIES = List.of(FILE_RESOURCE, MIME_TYPE);
+
+    public static final Relationship SUCCESS = new Relationship.Builder()
+            .name("success")
+            .build();
+
+    private static final Set<Relationship> RELATIONSHIPS = Set.of(SUCCESS);
+
+    @Override
+    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+        return PROPERTIES;
+    }
+
+    @Override
+    protected PropertyDescriptor getSupportedDynamicPropertyDescriptor(final String propertyDescriptorName) {
+        return new PropertyDescriptor.Builder()
+                .name(propertyDescriptorName)
+                .required(false)
+                .description("Specifies an attribute on generated FlowFiles defined by the Dynamic Property's key and value.")
+                .addValidator(StandardValidators.createAttributeExpressionLanguageValidator(AttributeExpression.ResultType.STRING, true))
+                .addValidator(StandardValidators.ATTRIBUTE_KEY_PROPERTY_NAME_VALIDATOR)
+                .expressionLanguageSupported(ExpressionLanguageScope.ENVIRONMENT)
+                .dynamic(true)
+                .build();
+    }
+
+    @Override
+    public Set<Relationship> getRelationships() {
+        return RELATIONSHIPS;
+    }
+
+    @Override
+    public void onTrigger(final ProcessContext context, final ProcessSession session) {
+        final Map<PropertyDescriptor, String> processorProperties = context.getProperties();
+        final Map<String, String> generatedAttributes = new HashMap<String, String>();
+        for (final Map.Entry<PropertyDescriptor, String> entry : processorProperties.entrySet()) {
+            final PropertyDescriptor property = entry.getKey();
+            if (property.isDynamic()) {
+                final String dynamicValue = context.getProperty(property).evaluateAttributeExpressions().getValue();
+                generatedAttributes.put(property.getName(), dynamicValue);
+            }
+        }
+
+        if (context.getProperty(MIME_TYPE).isSet()) {
+            generatedAttributes.put(CoreAttributes.MIME_TYPE.key(), context.getProperty(MIME_TYPE).getValue());
+        }
+
+        FlowFile flowFile = session.create();
+
+        try (final InputStream inputStream = context.getProperty(FILE_RESOURCE).asResource().read()) {
+            flowFile = session.write(flowFile, out -> StreamUtils.copy(inputStream, out));
+        } catch (IOException e) {
+            getLogger().error("Could not create FlowFile from Resource [{}]", context.getProperty(FILE_RESOURCE).getValue(), e);
+        }
+
+        flowFile = session.putAllAttributes(flowFile, generatedAttributes);
+        session.getProvenanceReporter().create(flowFile);
+        session.transfer(flowFile, SUCCESS);
+    }
+}
diff --git a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/resources/META-INF/services/org.apache.nifi.processor.Processor b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/resources/META-INF/services/org.apache.nifi.processor.Processor
index e547adbba1..6d74dc3669 100644
--- a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/resources/META-INF/services/org.apache.nifi.processor.Processor
+++ b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/resources/META-INF/services/org.apache.nifi.processor.Processor
@@ -52,6 +52,7 @@ org.apache.nifi.processors.standard.GenerateRecord
 org.apache.nifi.processors.standard.GenerateFlowFile
 org.apache.nifi.processors.standard.GenerateTableFetch
 org.apache.nifi.processors.standard.GetFile
+org.apache.nifi.processors.standard.GetFileResource
 org.apache.nifi.processors.standard.GetFTP
 org.apache.nifi.processors.standard.GetSFTP
 org.apache.nifi.processors.standard.HandleHttpRequest
diff --git a/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/test/java/org/apache/nifi/processors/standard/TestGetFileResource.java b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/test/java/org/apache/nifi/processors/standard/TestGetFileResource.java
new file mode 100644
index 0000000000..574946a2ac
--- /dev/null
+++ b/nifi-extension-bundles/nifi-standard-bundle/nifi-standard-processors/src/test/java/org/apache/nifi/processors/standard/TestGetFileResource.java
@@ -0,0 +1,59 @@
+/*
+ * 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.apache.nifi.processors.standard;
+
+import org.apache.nifi.flowfile.attributes.CoreAttributes;
+import org.apache.nifi.util.MockFlowFile;
+import org.apache.nifi.util.TestRunner;
+import org.apache.nifi.util.TestRunners;
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Unit tests for the GetFileResource processor.
+ */
+public class TestGetFileResource {
+
+    @Test
+    public void testInvalidConfiguration() {
+        final TestRunner runner = TestRunners.newTestRunner(new GetFileResource());
+        runner.setProperty(GetFileResource.FILE_RESOURCE, "");
+        runner.assertNotValid();
+    }
+
+    @Test
+    public void testGetFileResource() throws IOException {
+        final String filePath = "src/test/resources/TestCountText/jabberwocky.txt";
+        final TestRunner runner = TestRunners.newTestRunner(new GetFileResource());
+
+        runner.setProperty(GetFileResource.FILE_RESOURCE, filePath);
+        runner.setProperty(GetFileResource.MIME_TYPE, "text/plain");
+        runner.setProperty("foo", "foo");
+        runner.assertValid();
+
+        runner.run();
+
+        runner.assertTransferCount(GenerateFlowFile.SUCCESS, 1);
+        final MockFlowFile ff = runner.getFlowFilesForRelationship(GenerateFlowFile.SUCCESS).get(0);
+        ff.assertContentEquals(new File(filePath));
+        ff.assertAttributeEquals("foo", "foo");
+        ff.assertAttributeEquals(CoreAttributes.MIME_TYPE.key(), "text/plain");
+    }
+
+}
\ No newline at end of file