NIFI-145: Initial commit of bootstrap module

.gitignore

@@ -1,6 +1,7 @@
 target
 .project
 .settings
+.classpath
 nbactions.xml
 .DS_Store
 

nifi-bootstrap/pom.xml

@@ -0,0 +1,18 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<parent>
+		<groupId>org.apache.nifi</groupId>
+		<artifactId>nifi-parent</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+	</parent>
+
+	<artifactId>nifi-bootstrap</artifactId>
+	<packaging>jar</packaging>
+
+	<name>nifi-bootstrap</name>
+
+	<dependencies>
+	</dependencies>
+</project>

nifi-bootstrap/src/main/java/org/apache/nifi/bootstrap/RunNiFi.java

@@ -0,0 +1,176 @@
+package org.apache.nifi.bootstrap;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FilenameFilter;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+
+
+/**
+ * Bootstrap class to run Apache NiFi.
+ * 
+ * This class looks for the bootstrap.conf file by looking in the following places (in order):
+ * <ol>
+ * 	<li>First argument to the program</li>
+ *  <li>Java System Property named {@code org.apache.nifi.bootstrap.config.file}</li>
+ *  <li>${NIFI_HOME}/./conf/bootstrap.conf, where ${NIFI_HOME} references an environment variable {@code NIFI_HOME}</li>
+ *  <li>./conf/bootstrap.conf, where {@code .} represents the working directory.
+ * </ol>
+ *
+ * If the {@code bootstrap.conf} file cannot be found, throws a {@code FileNotFoundException].
+ */
+public class RunNiFi {
+	public static final String DEFAULT_CONFIG_FILE = "./conf/boostrap.conf";
+	public static final String DEFAULT_NIFI_PROPS_FILE = "./conf/nifi.properties";
+
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	public static void main(final String[] args) throws IOException, InterruptedException {
+		final ProcessBuilder builder = new ProcessBuilder();
+
+		String configFilename = (args.length > 0) ? args[0] : System.getProperty("org.apache.nifi.boostrap.config.file");
+
+		if ( configFilename == null ) {
+			final String nifiHome = System.getenv("NIFI_HOME");
+			if ( nifiHome != null ) {
+				final File nifiHomeFile = new File(nifiHome.trim());
+				final File configFile = new File(nifiHomeFile, DEFAULT_CONFIG_FILE);
+				configFilename = configFile.getAbsolutePath();
+			}
+		}
+
+		if ( configFilename == null ) {
+			configFilename = DEFAULT_CONFIG_FILE;
+		}
+
+		final File configFile = new File(configFilename);
+		if ( !configFile.exists() ) {
+			throw new FileNotFoundException(DEFAULT_CONFIG_FILE);
+		}
+
+		final Properties properties = new Properties();
+		try (final FileInputStream fis = new FileInputStream(configFile)) {
+			properties.load(fis);
+		}
+
+		final Map<String, String> props = new HashMap<>();
+		props.putAll( (Map) properties );
+
+		final String specifiedWorkingDir = props.get("working.dir");
+		if ( specifiedWorkingDir != null ) {
+			builder.directory(new File(specifiedWorkingDir));
+		}
+
+		final File workingDir = builder.directory();
+
+		final String libFilename = replaceNull(props.get("lib.dir"), "./lib").trim();
+		File libDir = getFile(libFilename, workingDir);
+
+		final String confFilename = replaceNull(props.get("conf.dir"), "./conf").trim();
+		File confDir = getFile(confFilename, workingDir);
+
+		String nifiPropsFilename = props.get("props.file");
+		if ( nifiPropsFilename == null ) {
+			if ( confDir.exists() ) {
+				nifiPropsFilename = new File(confDir, "nifi.properties").getAbsolutePath();
+			} else {
+				nifiPropsFilename = DEFAULT_CONFIG_FILE;
+			}
+		}
+
+		nifiPropsFilename = nifiPropsFilename.trim();
+
+		final List<String> javaAdditionalArgs = new ArrayList<>();
+		for ( final Map.Entry<String, String> entry : props.entrySet() ) {
+			final String key = entry.getKey();
+			final String value = entry.getValue();
+
+			if ( key.startsWith("java.arg") ) {
+				javaAdditionalArgs.add(value);
+			}
+		}
+
+		final File[] libFiles = libDir.listFiles(new FilenameFilter() {
+			@Override
+			public boolean accept(final File dir, final String filename) {
+				return filename.toLowerCase().endsWith(".jar");
+			}
+		});
+
+		if ( libFiles == null || libFiles.length == 0 ) {
+			throw new RuntimeException("Could not find lib directory at " + libDir.getAbsolutePath());
+		}
+
+		final File[] confFiles = confDir.listFiles();
+		if ( confFiles == null || confFiles.length == 0 ) {
+			throw new RuntimeException("Could not find conf directory at " + confDir.getAbsolutePath());
+		}
+
+		final Path workingDirPath = workingDir.toPath();
+		final List<String> cpFiles = new ArrayList<>(confFiles.length + libFiles.length);
+		cpFiles.add(confDir.getAbsolutePath());
+		for ( final File file : libFiles ) {
+			final Path path = workingDirPath.relativize(file.toPath());
+			final String cpPath = path.toString();
+			cpFiles.add(cpPath);
+		}
+
+		final StringBuilder classPathBuilder = new StringBuilder();
+		for (int i=0; i < cpFiles.size(); i++) {
+			final String filename = cpFiles.get(i);
+			classPathBuilder.append(filename);
+			if ( i < cpFiles.size() - 1 ) {
+				classPathBuilder.append(File.pathSeparatorChar);
+			}
+		}
+
+		final String classPath = classPathBuilder.toString();
+		String javaCmd = props.get("java");
+		if ( javaCmd == null ) {
+			javaCmd = "java";
+		}
+
+		final List<String> cmd = new ArrayList<>();
+		cmd.add(javaCmd);
+		cmd.add("-classpath");
+		cmd.add(classPath);
+		cmd.addAll(javaAdditionalArgs);
+		cmd.add("-Dnifi.properties.file.path=" + nifiPropsFilename);
+		cmd.add("org.apache.nifi.NiFi");
+
+		builder.command(cmd).inheritIO();
+
+		final StringBuilder cmdBuilder = new StringBuilder();
+		for ( final String s : cmd ) {
+			cmdBuilder.append(s).append(" ");
+		}
+		System.out.println("Starting Apache NiFi...");
+		System.out.println("Working Directory: " + workingDir.getAbsolutePath());
+		System.out.println("Command: " + cmdBuilder.toString());
+
+		final Process proc = builder.start();
+		Runtime.getRuntime().addShutdownHook(new ShutdownHook(proc));
+		final int statusCode = proc.waitFor();
+		System.out.println("Apache NiFi exited with Status Code " + statusCode);
+	}
+
+
+	private static File getFile(final String filename, final File workingDir) {
+		File libDir = new File(filename);
+		if ( !libDir.isAbsolute() ) {
+			libDir = new File(workingDir, filename);
+		}
+
+		return libDir;
+	}
+
+	private static String replaceNull(final String value, final String replacement) {
+		return (value == null) ? replacement : value;
+	}
+}

nifi-bootstrap/src/main/java/org/apache/nifi/bootstrap/ShutdownHook.java

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+package org.apache.nifi.bootstrap;
+
+public class ShutdownHook extends Thread {
+	private final Process nifiProcess;
+
+	public ShutdownHook(final Process nifiProcess) {
+		this.nifiProcess = nifiProcess;
+	}
+
+	@Override
+	public void run() {
+		nifiProcess.destroy();
+	}
+}