From fb9a647f3248bffc4bf9c8375d5ad40da43575ab Mon Sep 17 00:00:00 2001
From: pricelees <priceelees@gmail.com>
Date: Sun, 27 Jul 2025 22:34:21 +0900
Subject: [PATCH] =?UTF-8?q?feat:=20=EC=A0=84=EC=97=AD=EC=9C=BC=EB=A1=9C=20?=
 =?UTF-8?q?=EC=93=B0=EC=9D=B4=EB=8A=94=20Masking=20Converter=20=EA=B5=AC?=
 =?UTF-8?q?=ED=98=84=20=EB=B0=8F=20logback=20default=20=EC=84=A4=EC=A0=95?=
 =?UTF-8?q?=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../log/RoomescapeLogMaskingConverter.kt      | 77 +++++++++++++++++++
 src/main/resources/logback-local.xml          |  5 +-
 src/main/resources/logback-spring.xml         |  4 +
 3 files changed, 85 insertions(+), 1 deletion(-)
 create mode 100644 src/main/kotlin/roomescape/common/log/RoomescapeLogMaskingConverter.kt

diff --git a/src/main/kotlin/roomescape/common/log/RoomescapeLogMaskingConverter.kt b/src/main/kotlin/roomescape/common/log/RoomescapeLogMaskingConverter.kt
new file mode 100644
index 00000000..cb12be26
--- /dev/null
+++ b/src/main/kotlin/roomescape/common/log/RoomescapeLogMaskingConverter.kt
@@ -0,0 +1,77 @@
+package roomescape.common.log
+
+import ch.qos.logback.classic.pattern.MessageConverter
+import ch.qos.logback.classic.spi.ILoggingEvent
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.node.ArrayNode
+import com.fasterxml.jackson.databind.node.ObjectNode
+import com.fasterxml.jackson.databind.node.TextNode
+import io.github.oshai.kotlinlogging.KLogger
+import io.github.oshai.kotlinlogging.KotlinLogging
+import roomescape.common.config.JacksonConfig
+
+private val SENSITIVE_KEYS = setOf("password", "accessToken")
+private val log: KLogger = KotlinLogging.logger {}
+
+class RoomescapeLogMaskingConverter(
+    private val objectMapper: ObjectMapper = JacksonConfig().objectMapper()
+) : MessageConverter() {
+
+    override fun convert(event: ILoggingEvent): String {
+        val message: String = event.formattedMessage
+        log.warn { "[RoomescapeLogMaskingConverter.convert] formattedMessage: $message" }
+
+        return if (isJsonString(message)) {
+            maskedJsonString(message)
+        } else {
+            maskedPlainMessage(message)
+        }
+    }
+
+    private fun isJsonString(message: String): Boolean {
+        val trimmed = message.trim()
+
+        return trimmed.startsWith("{") && trimmed.endsWith("}")
+    }
+
+    private fun maskedJsonString(body: String): String = objectMapper.readValue(body, JsonNode::class.java)
+        .apply { maskRecursive(this) }
+        .toString()
+
+    private fun maskedPlainMessage(message: String): String {
+        val keys: String = SENSITIVE_KEYS.joinToString("|")
+        val regex = Regex("(?i)($keys)(\\s*=\\s*)(\\S+)")
+
+        return regex.replace(message) { matchResult ->
+            val key = matchResult.groupValues[1]
+            val delimiter = matchResult.groupValues[2]
+
+            "${key}${delimiter}****"
+        }
+    }
+
+    private fun maskRecursive(node: JsonNode?) {
+        node?.forEachEntry { key, childNode ->
+            when {
+                childNode.isValueNode -> {
+                    if (key in SENSITIVE_KEYS) (node as ObjectNode).put(key, "****")
+                }
+
+                childNode.isObject -> maskRecursive(childNode)
+                childNode.isArray -> {
+                    val arrayNode = childNode as ArrayNode
+                    val originSize = arrayNode.size()
+                    if (originSize > 1) {
+                        val first = arrayNode.first()
+                        arrayNode.removeAll()
+                        arrayNode.add(first)
+                        arrayNode.add(TextNode("(...logged only first of $originSize elements)"))
+                    }
+
+                    arrayNode.forEach { maskRecursive(it) }
+                }
+            }
+        }
+    }
+}
diff --git a/src/main/resources/logback-local.xml b/src/main/resources/logback-local.xml
index 2465fb75..1e7a67ba 100644
--- a/src/main/resources/logback-local.xml
+++ b/src/main/resources/logback-local.xml
@@ -1,7 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <included>
+    <conversionRule conversionWord="maskedMessage"
+                    class="roomescape.common.log.RoomescapeLogMaskingConverter" />
+
     <property name="CONSOLE_LOG_PATTERN"
-              value="%d{yyyy-MM-dd HH:mm:ss.SSS} %highlight(%-5level) %green(${PID:- }) --- [%15.15thread] %cyan(%-40logger{36}) : %msg%n%throwable"/>
+              value="%d{yyyy-MM-dd HH:mm:ss.SSS} %highlight(%-5level) %green(${PID:- }) --- [%15.15thread] %cyan(%-40logger{36}) : %maskedMessage%n%throwable"/>
 
     <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
         <encoder>
diff --git a/src/main/resources/logback-spring.xml b/src/main/resources/logback-spring.xml
index 69dd0b75..d60c1c92 100644
--- a/src/main/resources/logback-spring.xml
+++ b/src/main/resources/logback-spring.xml
@@ -3,4 +3,8 @@
     <springProfile name="local">
         <include resource="logback-local.xml"/>
     </springProfile>
+
+    <springProfile name="default">
+        <include resource="logback-local.xml"/>
+    </springProfile>
 </configuration>
\ No newline at end of file