AmazonEc2InstanceDataPropertySourceTest.java

/*
 * Copyright 2013-2014 the original author or authors.
 *
 * 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 org.springframework.cloud.aws.core.env.ec2;

import com.amazonaws.SDKGlobalConfiguration;
import com.amazonaws.util.EC2MetadataUtils;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;
import org.springframework.util.SocketUtils;

import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.net.InetSocketAddress;
import java.util.HashMap;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNull;

/**
 * @author Agim Emruli
 */
public class AmazonEc2InstanceDataPropertySourceTest {

    private static final int HTTP_SERVER_TEST_PORT = SocketUtils.findAvailableTcpPort();

    @SuppressWarnings("StaticNonFinalField")
    private static HttpServer httpServer;

    @Test
    public void getProperty_userDataWithDefaultFormatting_ReturnsUserDataKeys() throws Exception {
        //Arrange
        httpServer.createContext("/latest/user-data/", new StringWritingHttpHandler("keyA:valueA;keyB:valueB".getBytes("UTF-8")));

        //Act
        AmazonEc2InstanceDataPropertySource amazonEc2InstanceDataPropertySource = new AmazonEc2InstanceDataPropertySource("test");

        //Assert
        assertEquals("valueA", amazonEc2InstanceDataPropertySource.getProperty("keyA"));
        assertEquals("valueB", amazonEc2InstanceDataPropertySource.getProperty("keyB"));

        httpServer.removeContext("/latest/user-data/");
    }

    @Test
    public void getProperty_userDataWithCustomFormatting_ReturnsUserDataKeys() throws Exception {
        //Arrange
        httpServer.createContext("/latest/user-data/", new StringWritingHttpHandler("keyA=valueD,keyB=valueE".getBytes("UTF-8")));

        //Act
        AmazonEc2InstanceDataPropertySource amazonEc2InstanceDataPropertySource = new AmazonEc2InstanceDataPropertySource("test");

        amazonEc2InstanceDataPropertySource.setUserDataAttributeSeparator(",");
        amazonEc2InstanceDataPropertySource.setUserDataValueSeparator("=");

        //Assert
        assertEquals("valueD", amazonEc2InstanceDataPropertySource.getProperty("keyA"));
        assertEquals("valueE", amazonEc2InstanceDataPropertySource.getProperty("keyB"));

        httpServer.removeContext("/latest/user-data/");
    }

    @Test
    public void getProperty_knownAttribute_returnsAttributeValue() throws Exception {
        //Arrange
        httpServer.createContext("/latest/meta-data/instance-id", new StringWritingHttpHandler("i1234567".getBytes("UTF-8")));

        //Act
        AmazonEc2InstanceDataPropertySource amazonEc2InstanceDataPropertySource = new AmazonEc2InstanceDataPropertySource("test");

        //Assert
        assertEquals("i1234567", amazonEc2InstanceDataPropertySource.getProperty("instance-id"));

        httpServer.removeContext("/latest/meta-data/instance-id");
    }

    @Test
    public void getProperty_knownAttributeWithSubAttribute_returnsAttributeValue() throws Exception {
        //Arrange
        httpServer.createContext("/latest/meta-data/services/domain", new StringWritingHttpHandler("amazonaws.com".getBytes("UTF-8")));

        //Act
        AmazonEc2InstanceDataPropertySource amazonEc2InstanceDataPropertySource = new AmazonEc2InstanceDataPropertySource("test");

        //Assert
        assertEquals("amazonaws.com", amazonEc2InstanceDataPropertySource.getProperty("services/domain"));

        httpServer.removeContext("/latest/meta-data/services/domain");
    }

    @Test
    public void getProperty_unknownAttribute_returnsNull() throws Exception {
        //Arrange
        httpServer.createContext("/latest/meta-data/instance-id", new StringWritingHttpHandler("i1234567".getBytes("UTF-8")));

        //Act
        AmazonEc2InstanceDataPropertySource amazonEc2InstanceDataPropertySource = new AmazonEc2InstanceDataPropertySource("test");

        //Assert
        assertNull(amazonEc2InstanceDataPropertySource.getProperty("non-existing-attribute"));

        httpServer.removeContext("/latest/meta-data/instance-id");
    }

    @After
    public void clearMetadataCache() throws Exception {
        Field metadataCacheField = EC2MetadataUtils.class.getDeclaredField("cache");
        metadataCacheField.setAccessible(true);
        metadataCacheField.set(null, new HashMap<String, String>());
    }

    @BeforeClass
    public static void setupHttpServer() throws Exception {
        InetSocketAddress address = new InetSocketAddress(HTTP_SERVER_TEST_PORT);
        httpServer = HttpServer.create(address, -1);
        httpServer.start();
        overwriteMetadataEndpointUrl("http://" + address.getHostName() + ":" + address.getPort());
    }

    @AfterClass
    public static void shutdownHttpServer() throws Exception {
        if (httpServer != null) {
            httpServer.stop(10);
        }
        resetMetadataEndpointUrlOverwrite();
    }

    private static void overwriteMetadataEndpointUrl(String localMetadataServiceEndpointUrl) {
        System.setProperty(SDKGlobalConfiguration.EC2_METADATA_SERVICE_OVERRIDE_SYSTEM_PROPERTY, localMetadataServiceEndpointUrl);
    }

    private static void resetMetadataEndpointUrlOverwrite() {
        System.clearProperty(SDKGlobalConfiguration.EC2_METADATA_SERVICE_OVERRIDE_SYSTEM_PROPERTY);
    }

    private static class StringWritingHttpHandler implements HttpHandler {

        private final byte[] content;

        private StringWritingHttpHandler(byte[] content) {
            this.content = content;
        }

        @Override
        public void handle(HttpExchange httpExchange) throws IOException {
            httpExchange.sendResponseHeaders(200, this.content.length);
            OutputStream responseBody = httpExchange.getResponseBody();
            responseBody.write(this.content);
            responseBody.flush();
            responseBody.close();
        }
    }
}