| // SPDX-FileCopyrightText: © 2021 Matthias Andreas Benkard <code@mail.matthias.benkard.de> |
| // |
| // SPDX-License-Identifier: LGPL-3.0-or-later |
| |
| package eu.mulk.quarkus.googlecloud.jsonlogging; |
| |
| import java.io.PrintWriter; |
| import java.io.StringWriter; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.ServiceLoader; |
| import java.util.ServiceLoader.Provider; |
| import java.util.logging.Level; |
| import java.util.stream.Collectors; |
| import org.jboss.logmanager.ExtFormatter; |
| import org.jboss.logmanager.ExtLogRecord; |
| |
| /** |
| * Formats log records as JSON for consumption by Google Cloud Logging. |
| * |
| * <p>Meant to be used in containers running on Google Kubernetes Engine (GKE). |
| * |
| * @see LogEntry |
| */ |
| public class Formatter extends ExtFormatter { |
| |
| private static final String TRACE_LEVEL = "TRACE"; |
| private static final String DEBUG_LEVEL = "DEBUG"; |
| private static final String INFO_LEVEL = "INFO"; |
| private static final String WARNING_LEVEL = "WARNING"; |
| private static final String ERROR_LEVEL = "ERROR"; |
| |
| private static final String ERROR_EVENT_TYPE = |
| "type.googleapis.com/google.devtools.clouderrorreporting.v1beta1.ReportedErrorEvent"; |
| |
| private final List<StructuredParameterProvider> parameterProviders; |
| private final List<LabelProvider> labelProviders; |
| |
| /** |
| * Constructs a {@link Formatter} with custom configuration. |
| * |
| * <p><strong>Note:</strong> This constructor does not automatically discover providers using the |
| * {@link ServiceLoader} mechanism. See {@link #load} for this case use. |
| * |
| * @param parameterProviders the {@link StructuredParameterProvider}s to apply to each log entry. |
| * @param labelProviders the {@link LabelProvider}s to apply to each log entry. |
| */ |
| public Formatter( |
| Collection<StructuredParameterProvider> parameterProviders, |
| Collection<LabelProvider> labelProviders) { |
| this.parameterProviders = List.copyOf(parameterProviders); |
| this.labelProviders = List.copyOf(labelProviders); |
| } |
| |
| /** |
| * Constructs a {@link Formatter} with parameter and label providers supplied by {@link |
| * ServiceLoader}. |
| * |
| * <p>In addition to the providers supplied as parameters, this factory method loads all {@link |
| * StructuredParameterProvider}s and {@link LabelProvider}s found through the {@link |
| * ServiceLoader} mechanism. |
| * |
| * @param parameterProviders the {@link StructuredParameterProvider}s to apply to each log entry. |
| * @param labelProviders the {@link LabelProvider}s to apply to each log entry. |
| * @return a new formatter. |
| */ |
| public static Formatter load( |
| Collection<StructuredParameterProvider> parameterProviders, |
| Collection<LabelProvider> labelProviders) { |
| parameterProviders = new ArrayList<>(parameterProviders); |
| parameterProviders.addAll(loadStructuredParameterProviders()); |
| |
| labelProviders = new ArrayList<>(labelProviders); |
| labelProviders.addAll(loadLabelProviders()); |
| |
| return new Formatter(parameterProviders, labelProviders); |
| } |
| |
| private static List<StructuredParameterProvider> loadStructuredParameterProviders() { |
| return ServiceLoader.load(StructuredParameterProvider.class, Formatter.class.getClassLoader()) |
| .stream() |
| .map(Provider::get) |
| .collect(Collectors.toList()); |
| } |
| |
| private static List<LabelProvider> loadLabelProviders() { |
| return ServiceLoader.load(LabelProvider.class, Formatter.class.getClassLoader()).stream() |
| .map(Provider::get) |
| .collect(Collectors.toList()); |
| } |
| |
| @Override |
| public String format(ExtLogRecord logRecord) { |
| var message = formatMessageWithStackTrace(logRecord); |
| |
| List<StructuredParameter> parameters = new ArrayList<>(); |
| Map<String, String> labels = new HashMap<>(); |
| |
| var providerContext = new ProviderContext(logRecord); |
| |
| for (var parameterProvider : parameterProviders) { |
| var parameter = parameterProvider.getParameter(providerContext); |
| if (parameter != null) { |
| parameters.add(parameter); |
| } |
| } |
| |
| for (var labelProvider : labelProviders) { |
| var providedLabels = labelProvider.getLabels(providerContext); |
| if (providedLabels != null) { |
| for (var label : providedLabels) { |
| labels.put(label.key(), label.value()); |
| } |
| } |
| } |
| |
| if (logRecord.getParameters() != null) { |
| for (var parameter : logRecord.getParameters()) { |
| if (parameter instanceof StructuredParameter) { |
| parameters.add((StructuredParameter) parameter); |
| } else if (parameter instanceof Label) { |
| var label = (Label) parameter; |
| labels.put(label.key(), label.value()); |
| } |
| } |
| } |
| |
| var mdc = logRecord.getMdcCopy(); |
| var ndc = logRecord.getNdc(); |
| |
| var sourceLocation = |
| new LogEntry.SourceLocation( |
| logRecord.getSourceFileName(), |
| String.valueOf(logRecord.getSourceLineNumber()), |
| String.format( |
| "%s.%s", logRecord.getSourceClassName(), logRecord.getSourceMethodName())); |
| |
| var entry = |
| new LogEntry( |
| message, |
| severityOf(logRecord.getLevel()), |
| new LogEntry.Timestamp(logRecord.getInstant()), |
| null, |
| null, |
| sourceLocation, |
| labels, |
| parameters, |
| mdc, |
| ndc, |
| logRecord.getLevel().intValue() >= 1000 ? ERROR_EVENT_TYPE : null); |
| |
| return entry.json().build().toString() + "\n"; |
| } |
| |
| /** |
| * Formats the log message corresponding to {@code logRecord} including a stack trace of the |
| * {@link ExtLogRecord#getThrown()} exception if any. |
| */ |
| private String formatMessageWithStackTrace(ExtLogRecord logRecord) { |
| var messageStringWriter = new StringWriter(); |
| var messagePrintWriter = new PrintWriter(messageStringWriter); |
| messagePrintWriter.append(this.formatMessage(logRecord)); |
| |
| if (logRecord.getThrown() != null) { |
| messagePrintWriter.println(); |
| logRecord.getThrown().printStackTrace(messagePrintWriter); |
| } |
| |
| messagePrintWriter.close(); |
| return messageStringWriter.toString(); |
| } |
| |
| /** Computes the Google Cloud Logging severity corresponding to a given {@link Level}. */ |
| private static String severityOf(Level level) { |
| if (level.intValue() < 500) { |
| return TRACE_LEVEL; |
| } else if (level.intValue() < 700) { |
| return DEBUG_LEVEL; |
| } else if (level.intValue() < 900) { |
| return INFO_LEVEL; |
| } else if (level.intValue() < 1000) { |
| return WARNING_LEVEL; |
| } else { |
| return ERROR_LEVEL; |
| } |
| } |
| |
| /** |
| * An implementation of {@link LabelProvider.Context} and {@link |
| * StructuredParameterProvider.Context}. |
| */ |
| private static class ProviderContext |
| implements LabelProvider.Context, StructuredParameterProvider.Context { |
| |
| private final String loggerName; |
| private final long sequenceNumber; |
| private final String threadName; |
| |
| private ProviderContext(ExtLogRecord logRecord) { |
| loggerName = logRecord.getLoggerName(); |
| sequenceNumber = logRecord.getSequenceNumber(); |
| threadName = logRecord.getThreadName(); |
| } |
| |
| @Override |
| public String loggerName() { |
| return loggerName; |
| } |
| |
| @Override |
| public long sequenceNumber() { |
| return sequenceNumber; |
| } |
| |
| @Override |
| public String threadName() { |
| return threadName; |
| } |
| } |
| } |