improve logging

.env.example

@@ -1,3 +1,6 @@
+SPRING_ACTIVE_PROFILE=container
+SPRING_LOG_LEVEL=INFO
+
 DB_URL=localhost:5432
 DB_NAME=demo
 DB_SCHEMA=public

build.gradle.kts

@@ -27,6 +27,7 @@ dependencies {
 	implementation("com.fasterxml.jackson.module:jackson-module-kotlin:2.15.4")
 	implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.15.4")
 	implementation("io.github.optimumcode:json-schema-validator:0.2.3")
+	implementation("net.logstash.logback:logstash-logback-encoder:8.0")
 	implementation("org.flywaydb:flyway-core:9.22.3")
 	implementation("org.jetbrains.kotlin:kotlin-reflect:2.0.20")
 	implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.3")

docker-compose.yml

@@ -6,6 +6,8 @@ services:
       dockerfile: Dockerfile
       context: .
     environment:
+      SPRING_LOG_LEVEL: $SPRING_LOG_LEVEL
+      SPRING_ACTIVE_PROFILE: $SPRING_ACTIVE_PROFILE
       DB_URL: $DB_URL
       DB_NAME: $DB_NAME
       DB_SCHEMA: $DB_SCHEMA

src/main/kotlin/com/example/demo/services/database/product/ProductServiceImpl.kt

@@ -5,6 +5,8 @@ import com.example.demo.providers.ProductRepository
 import com.example.demo.services.database.exceptions.AlreadyDeletedException
 import com.example.demo.services.database.product.exceptions.ProductNotFoundException
 import com.example.demo.services.kafka.Producer
+import com.example.demo.utils.LoggerDelegate
+import net.logstash.logback.marker.Markers
 import org.springframework.data.domain.Page
 import org.springframework.data.domain.Pageable
 import java.time.OffsetDateTime
@@ -15,7 +17,15 @@ class ProductServiceImpl(
     private val productRepository: ProductRepository,
     private val producer: Producer,
 ): ProductService {
+    private val logger by LoggerDelegate()
+
     override fun findByGuid(guid: UUID): Product? = productRepository.findByGuid(guid)
+        .also {
+            logger.debug(
+                Markers.appendEntries(mapOf("guid" to guid, "idResult" to it?.id)),
+                "find product by guid",
+            )
+        }
 
     override fun findAll(pageable: Pageable): Page<Product> = productRepository.findAll(pageable)
 

src/main/kotlin/com/example/demo/utils/Logger.kt

@@ -0,0 +1,24 @@
+package com.example.demo.utils
+
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+import kotlin.reflect.full.companionObject
+
+/**
+ * usage: `private val logger by LoggerDelegate()`
+ */
+class LoggerDelegate<in R : Any> : ReadOnlyProperty<R, Logger> {
+    override fun getValue(thisRef: R, property: KProperty<*>)
+            = getLogger(getClassForLogging(thisRef.javaClass))
+
+    private fun <T : Any> getClassForLogging(javaClass: Class<T>): Class<*> {
+        return javaClass.enclosingClass?.takeIf {
+            it.kotlin.companionObject?.java == javaClass
+        } ?: javaClass
+    }
+}
+
+
+fun getLogger(forClass: Class<*>): Logger = LoggerFactory.getLogger(forClass)

src/main/resources/application.yml

@@ -14,6 +14,12 @@ spring:
     locations: classpath:db/migration/structure, classpath:db/migration/data # the location where flyway should look for migration scripts
     validate-on-migrate: true
     default-schema: ${DB_SCHEMA:public}
+  profiles:
+    active: ${SPRING_ACTIVE_PROFILE:default}
+
+logging:
+  level:
+    root: ${SPRING_LOG_LEVEL:INFO}
 
 kafka:
   bootstrap-servers: ${KAFKA_SERVERS:localhost:9095}

src/main/resources/logback-spring.xml

@@ -0,0 +1,15 @@
+<configuration>
+    <springProfile name="default">
+        <include resource="org/springframework/boot/logging/logback/base.xml" />
+    </springProfile>
+
+    <springProfile name="container">
+        <appender name="jsonConsoleAppender" class="ch.qos.logback.core.ConsoleAppender">
+            <encoder class="net.logstash.logback.encoder.LogstashEncoder" />
+        </appender>
+
+        <root level="INFO">
+            <appender-ref ref="jsonConsoleAppender" />
+        </root>
+    </springProfile>
+</configuration>