Add Logging:

* JSON format for the stdout in production environment in order to capture it while running on Docker/Kubernetes
* Readable format for the stdout in test environment in order to easily debug issues

Author: JavierCane

.gitignore

@@ -5,3 +5,5 @@ build/
 # Ignore Gradle GUI config
 gradle-app.setting
 
+var/log/*
+!var/log/.gitkeep

build.gradle

@@ -8,8 +8,11 @@ repositories {
 }
 
 dependencies {
-    testCompile('org.junit.jupiter:junit-jupiter-api:5.5.1')
-    testRuntimeOnly('org.junit.jupiter:junit-jupiter-engine:5.5.1')
+    implementation 'org.apache.logging.log4j:log4j-core:2.12.1'
+    implementation 'com.vlkan.log4j2:log4j2-logstash-layout:0.19'
+
+    testCompile 'org.junit.jupiter:junit-jupiter-api:5.5.1'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.5.1'
 }
 
 test {

src/main/resources/log4j2.properties

@@ -0,0 +1,34 @@
+name = CodelyTvJavaBasicSkeleton
+property.filename = logs
+appenders = console, file
+
+status = warn
+
+appender.console.name = CONSOLE
+appender.console.type = CONSOLE
+appender.console.target = SYSTEM_OUT
+
+appender.console.logstash.type = LogstashLayout
+appender.console.logstash.dateTimeFormatPattern = yyyy-MM-dd'T'HH:mm:ss.SSSZZZ
+appender.console.logstash.eventTemplateUri = classpath:LogstashJsonEventLayoutV1.json
+appender.console.logstash.prettyPrintEnabled = true
+appender.console.logstash.stackTraceEnabled = true
+
+appender.file.type = File
+appender.file.name = LOGFILE
+appender.file.fileName=var/log/java-basic-skeleton.log
+appender.file.logstash.type=LogstashLayout
+appender.file.logstash.dateTimeFormatPattern = yyyy-MM-dd'T'HH:mm:ss.SSSZZZ
+appender.file.logstash.eventTemplateUri = classpath:LogstashJsonEventLayoutV1.json
+appender.file.logstash.prettyPrintEnabled = false
+appender.file.logstash.stackTraceEnabled = true
+
+loggers = file
+logger.file.name = tv.codely.java_basic_skeleton
+logger.file.level = info
+logger.file.appenderRefs = file
+logger.file.appenderRef.file.ref = LOGFILE
+
+rootLogger.level = info
+rootLogger.appenderRefs = stdout
+rootLogger.appenderRef.stdout.ref = CONSOLE

src/test/java/tv/codely/java_basic_skeleton/GreeterShould.java

@@ -2,6 +2,8 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.junit.jupiter.api.Test;
 
 public class GreeterShould {
@@ -12,4 +14,11 @@ void greet_with_a_hello_message_to_the_name_it_receives() {
 		assertEquals("Hello Jhon", greeter.greet("Jhon"));
 	}
 
+	@Test
+	void save_logs_to_the_file() {
+		Logger logger = LogManager.getLogger(GreeterShould.class);
+		RuntimeException error = new RuntimeException("exceptioooon");
+		logger.error("Hello error world!", error);
+	}
+
 }

src/test/resources/log4j2.properties

@@ -0,0 +1,33 @@
+name = CodelyTvJavaBasicSkeleton
+property.filename = logs
+appenders = console, file
+
+status = warn
+
+appender.console.name = CONSOLE
+appender.console.type = CONSOLE
+appender.console.target = SYSTEM_OUT
+
+appender.console.layout.type = PatternLayout
+appender.console.layout.pattern = [%level] [%date{HH:mm:ss.SSS}] [%class{0}#%method:%line] %message \(%mdc\) %n%throwable
+appender.console.filter.threshold.type = ThresholdFilter
+appender.console.filter.threshold.level = info
+
+appender.file.type = File
+appender.file.name = LOGFILE
+appender.file.fileName=var/log/java-basic-skeleton-test.log
+appender.file.logstash.type=LogstashLayout
+appender.file.logstash.dateTimeFormatPattern = yyyy-MM-dd'T'HH:mm:ss.SSSZZZ
+appender.file.logstash.eventTemplateUri = classpath:LogstashJsonEventLayoutV1.json
+appender.file.logstash.prettyPrintEnabled = false
+appender.file.logstash.stackTraceEnabled = true
+
+loggers = file
+logger.file.name = tv.codely.java_basic_skeleton
+logger.file.level = info
+logger.file.appenderRefs = file
+logger.file.appenderRef.file.ref = LOGFILE
+
+rootLogger.level = info
+rootLogger.appenderRefs = stdout
+rootLogger.appenderRef.stdout.ref = CONSOLE