Initial checkin: Quarkus Google Cloud JSON Logging.
Change-Id: I264211f56c2bed4002ecdb6ead8a5321ada855fd
diff --git a/runtime/src/main/java/eu/mulk/quarkus/observability/googlecloud/jsonlogging/GoogleCloudLoggingFormatter.java b/runtime/src/main/java/eu/mulk/quarkus/observability/googlecloud/jsonlogging/GoogleCloudLoggingFormatter.java
new file mode 100644
index 0000000..a44e8b5
--- /dev/null
+++ b/runtime/src/main/java/eu/mulk/quarkus/observability/googlecloud/jsonlogging/GoogleCloudLoggingFormatter.java
@@ -0,0 +1,115 @@
+package eu.mulk.quarkus.observability.googlecloud.jsonlogging;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.HashMap;
+import java.util.logging.Level;
+import javax.json.bind.Jsonb;
+import javax.json.bind.JsonbException;
+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 GoogleCloudLogEntry
+ */
+class GoogleCloudLoggingFormatter 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 Jsonb jsonb;
+
+ GoogleCloudLoggingFormatter(Jsonb jsonb) {
+ this.jsonb = jsonb;
+ }
+
+ @Override
+ public String format(ExtLogRecord logRecord) {
+ var message = formatMessageWithStackTrace(logRecord);
+
+ var parameters = new HashMap<String, Object>();
+ var labels = new HashMap<String, String>();
+ if (logRecord.getParameters() != null) {
+ for (var parameter : logRecord.getParameters()) {
+ if (parameter instanceof KeyValueParameter kvparam) {
+ parameters.put(kvparam.key(), kvparam.value());
+ } else if (parameter instanceof Label label) {
+ labels.put(label.key(), label.value());
+ }
+ }
+ }
+
+ var mdc = logRecord.getMdcCopy();
+ var ndc = logRecord.getNdc();
+
+ var sourceLocation =
+ new GoogleCloudLogEntry.SourceLocation(
+ logRecord.getSourceFileName(), String.valueOf(logRecord.getSourceLineNumber()), String.format("%s.%s", logRecord.getSourceClassName(), logRecord.getSourceMethodName()));
+
+ var entry =
+ new GoogleCloudLogEntry(
+ message,
+ severityOf(logRecord.getLevel()),
+ new GoogleCloudLogEntry.Timestamp(logRecord.getInstant()),
+ null,
+ null,
+ sourceLocation,
+ labels.isEmpty() ? null : labels,
+ parameters.isEmpty() ? null : parameters,
+ mdc.isEmpty() ? null : mdc,
+ ndc.isEmpty() ? null : ndc,
+ logRecord.getLevel().intValue() >= 1000 ? ERROR_EVENT_TYPE : null);
+
+ try {
+ return jsonb.toJson(entry) + "\n";
+ } catch (JsonbException e) {
+ e.printStackTrace();
+ return message + "\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;
+ }
+ }
+}