Introduce JSON logging

Fixes quarkusio#1847

core/runtime/src/main/java/io/quarkus/runtime/logging/ConsoleConfig.java

@@ -36,6 +36,17 @@ public class ConsoleConfig {
     @ConfigItem(defaultValue = "%d{yyyy-MM-dd HH:mm:ss,SSS} %-5p [%c{3.}] (%t) %s%e%n")
     String format;
 
+    /**
+     * The type of output format to use.
+     */
+    @ConfigItem(defaultValue = "text")
+    FormatType formatType;
+
+    /**
+     * JSON format configuration.
+     */
+    JsonConfig json;
+
     /**
      * The console log level
      */

core/runtime/src/main/java/io/quarkus/runtime/logging/FormatType.java

@@ -0,0 +1,26 @@
+package io.quarkus.runtime.logging;
+
+/**
+ * The type of formatter to use.
+ */
+public enum FormatType {
+    /**
+     * Format in text for person-readability.
+     */
+    TEXT,
+    /**
+     * Format in JSON for machine-readability.
+     */
+    JSON,
+    ;
+
+    public static FormatType of(String str) {
+        if (str.equalsIgnoreCase("text")) {
+            return TEXT;
+        } else if (str.equalsIgnoreCase("json")) {
+            return JSON;
+        } else {
+            throw new IllegalArgumentException("Unrecognized value: " + str);
+        }
+    }
+}

core/runtime/src/main/java/io/quarkus/runtime/logging/JsonConfig.java

@@ -0,0 +1,16 @@
+package io.quarkus.runtime.logging;
+
+import io.quarkus.runtime.annotations.ConfigGroup;
+import io.quarkus.runtime.annotations.ConfigItem;
+
+/**
+ * JSON-specific logging configuration.
+ */
+@ConfigGroup
+public class JsonConfig {
+    /**
+     * Enable logging of call details (method name, class name, etc.) into the JSON output.
+     */
+    @ConfigItem
+    public boolean callDetails;
+}

core/runtime/src/main/java/io/quarkus/runtime/logging/LoggingSetupTemplate.java

@@ -6,6 +6,7 @@
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.logging.ErrorManager;
+import java.util.logging.Formatter;
 import java.util.logging.Handler;
 import java.util.logging.Level;
 
@@ -15,6 +16,7 @@
 import org.jboss.logmanager.Logger;
 import org.jboss.logmanager.errormanager.OnlyOnceErrorManager;
 import org.jboss.logmanager.formatters.ColorPatternFormatter;
+import org.jboss.logmanager.formatters.JsonFormatter;
 import org.jboss.logmanager.formatters.PatternFormatter;
 import org.jboss.logmanager.handlers.ConsoleHandler;
 import org.jboss.logmanager.handlers.FileHandler;
@@ -50,11 +52,20 @@ public void initializeLogging(LogConfig config) {
         }
         ArrayList<Handler> handlers = new ArrayList<>(2);
         if (config.console.enable) {
-            final PatternFormatter formatter;
-            if (config.console.color && System.console() != null) {
-                formatter = new ColorPatternFormatter(config.console.darken, config.console.format);
+            final Formatter formatter;
+            if (config.console.formatType == FormatType.JSON) {
+                JsonFormatter jsonFormatter = new JsonFormatter();
+                if (config.console.json.callDetails) {
+                    jsonFormatter.setPrintDetails(true);
+                }
+                formatter = jsonFormatter;
             } else {
-                formatter = new PatternFormatter(config.console.format);
+                assert config.console.formatType == FormatType.TEXT;
+                if (config.console.color && System.console() != null) {
+                    formatter = new ColorPatternFormatter(config.console.darken, config.console.format);
+                } else {
+                    formatter = new PatternFormatter(config.console.format);
+                }
             }
             final ConsoleHandler handler = new ConsoleHandler(formatter);
             handler.setLevel(config.console.level);

docs/src/main/asciidoc/logging-guide.adoc

@@ -21,9 +21,10 @@ Console logging is enabled by default.  To configure or disable it, the followin
 |===
 |Property Name|Default|Description
 |quarkus.log.console.enable|true|Determine whether console logging is enabled.
-|quarkus.log.console.format|%d{yyyy-MM-dd HH:mm:ss,SSS} %-5p [%c{3.}] (%t) %s%e%n|The format pattern to use for logging to the console; see <<format_string>>.
+|quarkus.log.console.format|%d{yyyy-MM-dd HH:mm:ss,SSS} %-5p [%c{3.}] (%t) %s%e%n|The format pattern to use for `text` logging to the console; see <<format_string>>.
+|quarkus.log.console.format-type|text|The type of formatter to use for the console; valid values are `text` or `json` (see <<json_config>>).
 |quarkus.log.console.level|INFO|The minimum log level to display to the console.
-|quarkus.log.console.color|true|Allow color rendering to be used on the console, if it is supported by the terminal.
+|quarkus.log.console.color|true|Allow color rendering to be used on the console in `text` mode, if it is supported by the terminal.
 |===
 
 === File configuration
@@ -39,6 +40,17 @@ Logging to a file is also supported but not enabled by default.  To configure or
 |quarkus.log.file.path|quarkus.log|The path of the log file.
 |===
 
+[id="json_config"]
+=== JSON configuration
+
+When outputting in JSON format, it is possible to configure additional properties.
+
+[cols="<m,<m,<2",options="header"]
+|===
+|Property Name|Default|Description
+|quarkus.log.console.json.call-details|false|Determine whether extra detail (class name, method name, source file, etc.) should be included in the log output.
+|===
+
 === Logging categories
 
 Logging is done on a per-category basis.  Each category can be independently configured.
@@ -130,6 +142,14 @@ quarkus.log.category."io.quarkus.smallrye.jwt".level=TRACE
 quarkus.log.category."io.undertow.request.security".level=TRACE
 ----
 
+.JSON Console Logging With Extended Call Details
+[source, properties]
+----
+quarkus.log.console.enable=true
+quarkus.log.console.format-type=json
+quarkus.log.console.json.call-details=true
+----
+
 == Supported Logging APIs
 
 Applications and components may use any of the following APIs for logging, and the logs will be merged: