Github user nickwallen commented on a diff in the pull request:
https://github.com/apache/metron/pull/884#discussion_r158654855
--- Diff:
metron-stellar/stellar-common/src/main/java/org/apache/metron/stellar/common/shell/cli/StellarShell.java
---
@@ -0,0 +1,409 @@
+/*
+ *
+ * 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.metron.stellar.common.shell.cli;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.google.common.base.Splitter;
+import com.google.common.collect.Iterables;
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.CommandLineParser;
+import org.apache.commons.cli.HelpFormatter;
+import org.apache.commons.cli.Option;
+import org.apache.commons.cli.Options;
+import org.apache.commons.cli.PosixParser;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.log4j.PropertyConfigurator;
+import org.apache.metron.stellar.common.shell.DefaultStellarAutoCompleter;
+import org.apache.metron.stellar.common.shell.DefaultStellarShellExecutor;
+import org.apache.metron.stellar.common.shell.StellarAutoCompleter;
+import org.apache.metron.stellar.common.shell.StellarShellExecutor;
+import org.apache.metron.stellar.common.shell.StellarShellResult;
+import org.apache.metron.stellar.common.utils.ConversionUtils;
+import org.apache.metron.stellar.common.utils.JSONUtils;
+import org.jboss.aesh.complete.CompleteOperation;
+import org.jboss.aesh.complete.Completion;
+import org.jboss.aesh.console.AeshConsoleCallback;
+import org.jboss.aesh.console.Console;
+import org.jboss.aesh.console.ConsoleOperation;
+import org.jboss.aesh.console.Prompt;
+import org.jboss.aesh.console.settings.SettingsBuilder;
+import org.jboss.aesh.terminal.CharacterType;
+import org.jboss.aesh.terminal.Color;
+import org.jboss.aesh.terminal.TerminalCharacter;
+import org.jboss.aesh.terminal.TerminalColor;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Properties;
+
+import static org.apache.metron.stellar.dsl.Context.Capabilities.CONSOLE;
+import static
org.apache.metron.stellar.dsl.Context.Capabilities.GLOBAL_CONFIG;
+import static
org.apache.metron.stellar.dsl.Context.Capabilities.SHELL_VARIABLES;
+
+/**
+ * A REPL environment for Stellar.
+ *
+ * Useful for debugging Stellar expressions.
+ */
+public class StellarShell extends AeshConsoleCallback implements
Completion {
+
+ private static final String WELCOME = "Stellar, Go!\n" +
+ "Functions are loading lazily in the background and will be
unavailable until loaded fully.";
+
+ private List<TerminalCharacter> EXPRESSION_PROMPT = new
ArrayList<TerminalCharacter>()
+ {{
+ add(new TerminalCharacter('[', new TerminalColor(Color.RED,
Color.DEFAULT)));
+ add(new TerminalCharacter('S', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.BOLD));
+ add(new TerminalCharacter('t', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.BOLD));
+ add(new TerminalCharacter('e', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.BOLD));
+ add(new TerminalCharacter('l', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.BOLD));
+ add(new TerminalCharacter('l', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.BOLD));
+ add(new TerminalCharacter('a', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.BOLD));
+ add(new TerminalCharacter('r', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.BOLD));
+ add(new TerminalCharacter(']', new TerminalColor(Color.RED,
Color.DEFAULT)));
+ add(new TerminalCharacter('>', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.UNDERLINE));
+ add(new TerminalCharacter('>', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.UNDERLINE));
+ add(new TerminalCharacter('>', new TerminalColor(Color.GREEN,
Color.DEFAULT), CharacterType.UNDERLINE));
+ add(new TerminalCharacter(' ', new TerminalColor(Color.DEFAULT,
Color.DEFAULT)));
+ }};
+
+ public static final String ERROR_PROMPT = "[!] ";
+ public static final String STELLAR_PROPERTIES_FILENAME =
"stellar.properties";
+
+ /**
+ * Executes Stellar expressions for the shell environment.
+ */
+ private StellarShellExecutor executor;
+
+ /**
+ * The Aesh shell console.
+ */
+ private Console console;
+
+ /**
+ * Provides auto-complete functionality.
+ */
+ private StellarAutoCompleter autoCompleter;
+
+ /**
+ * Execute the Stellar REPL.
+ */
+ public static void main(String[] args) throws Exception {
+ StellarShell shell = new StellarShell(args);
+ shell.run();
+ }
+
+ /**
+ * Create a Stellar REPL.
+ * @param args The commmand-line arguments.
+ */
+ public StellarShell(String[] args) throws Exception {
+
+ // define valid command-line options
+ CommandLineParser parser = new PosixParser();
+ Options options = defineCommandLineOptions();
+ CommandLine commandLine = parser.parse(options, args);
+
+ // print help
+ if(commandLine.hasOption("h")) {
+ HelpFormatter formatter = new HelpFormatter();
+ formatter.printHelp("stellar", options);
+ System.exit(0);
+ }
+
+ // validate the command line options
+ try {
+ StellarShellOptionsValidator.validateOptions(commandLine);
+
+ } catch(IllegalArgumentException e){
+ System.err.println(e.getMessage());
+ System.exit(1);
+ }
+
+ // setup logging, if specified
+ if(commandLine.hasOption("l")) {
+ PropertyConfigurator.configure(commandLine.getOptionValue("l"));
+ }
+
+ console = createConsole(commandLine);
+ autoCompleter = new DefaultStellarAutoCompleter();
+ executor = createExecutor(commandLine, console,
getStellarProperties(commandLine), autoCompleter);
+
+ loadVariables(commandLine, executor);
+ console.setPrompt(new Prompt(EXPRESSION_PROMPT));
+ console.addCompletion(this);
+ console.setConsoleCallback(this);
+ }
+
+ /**
+ * @return The valid command line options.
+ */
+ private Options defineCommandLineOptions() {
+ Options options = new Options();
+ options.addOption(
+ "z",
+ "zookeeper",
+ true,
+ "Zookeeper URL fragment in the form
[HOSTNAME|IPADDRESS]:PORT");
+ options.addOption(
+ "v",
+ "variables",
+ true,
+ "File containing a JSON Map of variables");
+ options.addOption(
+ "irc",
+ "inputrc",
+ true,
+ "File containing the inputrc if not the default ~/.inputrc");
+ options.addOption(
+ "na",
+ "no_ansi",
+ false,
+ "Make the input prompt not use ANSI colors.");
+ options.addOption(
+ "h",
+ "help",
+ false,
+ "Print help");
+ options.addOption(
+ "p",
+ "properties",
+ true,
+ "File containing Stellar properties");
+ Option log4j = new Option(
+ "l",
+ "log4j",
+ true,
+ "The log4j properties file to load");
+ log4j.setArgName("FILE");
+ log4j.setRequired(false);
+ options.addOption(log4j);
+
+ return options;
+ }
+
+ /**
+ * Loads any variables defined in an external file.
+ * @param commandLine The command line arguments.
+ * @param executor The stellar executor.
+ * @throws IOException
+ */
+ private static void loadVariables(
+ CommandLine commandLine,
+ StellarShellExecutor executor) throws IOException {
+
+ if(commandLine.hasOption("v")) {
+
+ // load variables defined in a file
+ String variablePath = commandLine.getOptionValue("v");
+ Map<String, Object> variables = JSONUtils.INSTANCE.load(
+ new File(variablePath),
+ new TypeReference<Map<String, Object>>() {});
+
+ // for each variable...
+ for(Map.Entry<String, Object> kv : variables.entrySet()) {
+ String variable = kv.getKey();
+ Object value = kv.getValue();
+
+ // define the variable - no expression available
+ executor.assign(variable, value, Optional.empty());
+ }
+ }
+ }
+
+ /**
+ * Creates the Stellar execution environment.
+ * @param commandLine The command line arguments.
+ * @param console The console which drives the REPL.
+ * @param properties Stellar properties.
+ */
+ private StellarShellExecutor createExecutor(
+ CommandLine commandLine,
+ Console console,
+ Properties properties,
+ StellarAutoCompleter autoCompleter) throws Exception {
+
+ Optional<String> zookeeperUrl = Optional.empty();
+ if(commandLine.hasOption("z")) {
+ zookeeperUrl = Optional.of(commandLine.getOptionValue("z"));
+ }
+
+ StellarShellExecutor executor = new
DefaultStellarShellExecutor(properties, zookeeperUrl);
+
+ // the CONSOLE capability is only available with the Aesh-driven REPL
+ executor.getContext().addCapability(CONSOLE, () -> console);
+
+ // allows some Stellar functions to access Stellar internals; should
probably use %magics instead
+ executor.getContext().addCapability(SHELL_VARIABLES, () ->
executor.getState());
+
+ // register the auto-completer to be notified when needed
+ executor.addSpecialListener((magic) ->
autoCompleter.addCandidateFunction(magic.getCommand()));
+ executor.addFunctionListener((fn) ->
autoCompleter.addCandidateFunction(fn.getName()));
+ executor.addVariableListener((name, val) ->
autoCompleter.addCandidateVariable(name));
+
+ executor.init();
+ return executor;
+ }
+
+ /**
+ * Creates the REPL's console.
+ * @param commandLine The command line options.
+ */
+ private Console createConsole(CommandLine commandLine) {
+
+ // console settings
+ boolean useAnsi = !commandLine.hasOption("na");
+ SettingsBuilder settings = new SettingsBuilder().enableAlias(true)
+ .enableMan(true)
+ .ansi(useAnsi)
+ .parseOperators(false)
+
.inputStream(PausableInput.INSTANCE);
+
+ if(commandLine.hasOption("irc")) {
+ settings = settings.inputrc(new
File(commandLine.getOptionValue("irc")));
+ }
+
+ return new Console(settings.create());
+ }
+
+ /**
+ * Retrieves the Stellar properties. The properties are either loaded
from a file in
+ * the classpath or a set of defaults are used.
+ */
+ private Properties getStellarProperties(CommandLine commandLine) throws
IOException {
+ Properties properties = new Properties();
+
+ if (commandLine.hasOption("p")) {
+ // attempt to load properties from a file specified on the
command-line
+ try (InputStream in = new
FileInputStream(commandLine.getOptionValue("p"))) {
+ if(in != null) {
+ properties.load(in);
+ }
+ }
+
+ } else {
+ // otherwise attempt to load properties from the classpath
+ try (InputStream in =
getClass().getClassLoader().getResourceAsStream(STELLAR_PROPERTIES_FILENAME)) {
+ if(in != null) {
+ properties.load(in);
+ }
+ }
+ }
+
+ return properties;
+ }
+
+ /**
+ * Handles the main loop for the REPL.
+ */
+ public void run() {
+ // welcome message
+ writeLine(WELCOME);
+
+ // print the globals if we got 'em
+ executor.getContext()
+ .getCapability(GLOBAL_CONFIG, false)
+ .ifPresent(conf -> writeLine(conf.toString()));
+
+ console.start();
+ }
+
+ /**
+ * Quits the console.
+ */
+ private void handleQuit() {
+ try {
+ console.stop();
+ } catch (Throwable e) {
+ e.printStackTrace();
+ }
+ }
+
+ private void writeLine(String out) {
+ console.getShell().out().println(out);
+ }
+
+ @Override
+ public int execute(ConsoleOperation output) throws InterruptedException {
+
+ // grab the expression
+ String expression = output.getBuffer().trim();
+ if(StringUtils.isNotBlank(expression) ) {
+
+ // execute the expression
+ StellarShellResult result = executor.execute(expression);
+
+ if(result.isSuccess()) {
+ result.getValue().ifPresent(v ->
writeLine(ConversionUtils.convert(v, String.class)));
+
+ } else if (result.isError()) {
+ result.getException().ifPresent(e -> writeLine(ERROR_PROMPT +
e.getMessage()));
+ result.getException().ifPresent(e -> e.printStackTrace());
+
+ } else if(result.isTerminate()) {
+ handleQuit();
+
+ } else {
+ throw new IllegalStateException("An execution result is neither a
success nor a failure. Please file a bug report.");
+ }
+ }
+
+ return 0;
+ }
+
+ /**
+ * Performs auto-completion for the shell.
+ * @param completeOperation The auto-complete operation.
+ */
+ @Override
+ public void complete(CompleteOperation completeOperation) {
+ String buffer = completeOperation.getBuffer();
--- End diff --
Ties our generic autocompleter to the autocomplete interface required by
Aesh.
---
