Add loggers for requests and responses

Author: debuglevel

README.md

@@ -38,4 +38,9 @@ The JSON object looks like this as of version 0.0.12:
     "vmVersion":"25.131-b11",
     "compilerName":"HotSpot 64-Bit Tiered Compilers"
 }
-```
+```
+
+## Build and Publish
+Developer's notes on how to publish this artifact on bintray via PowerShell:
+* ensure to increment version in `gradle.build`
+* `$env:BINTRAY_USER = "debuglevel"; $env:BINTRAY_API_KEY = "SUPER_SECRET"; ./gradlew bintrayUpload`

build.gradle

@@ -28,7 +28,7 @@ compileTestKotlin {
 }
 
 group 'de.debuglevel.sparkmicroserviceutils'
-version '0.0.20'
+version '0.0.21'
 
 sourceCompatibility = 1.8
 

src/main/kotlin/de/debuglevel/microservices/utils/logging/RequestLogger.kt

@@ -0,0 +1,60 @@
+package de.debuglevel.microservices.utils.logging
+
+import mu.KotlinLogging
+import spark.Request
+import spark.Response
+import java.nio.charset.Charset
+import java.time.LocalDateTime
+
+private val logger = KotlinLogging.logger {}
+
+fun buildRequestLog(request: Request): String {
+    val accept = request.headers("accept") ?: "<UNKNOWN>"
+
+    return "Handling ${request.protocol()} ${request.requestMethod()} ${request.url()} from ${request.ip()} accepting $accept ..."
+}
+
+fun buildResponseLog(request: Request, response: Response): String {
+    val raw = response.raw()
+
+    val accept = request.headers("accept") ?: "<UNKNOWN>"
+    val statuscode = raw.status
+    val contentType = raw.getHeader("content-type") ?: "<UNKNOWN>"
+
+    request.raw()
+
+    val size = try {
+        response.body().toByteArray(Charset.forName(raw.characterEncoding)).size.toString() + " bytes"
+    } catch (e: Exception) {
+        "unknown bytes"
+    }
+
+    return "Handled ${request.protocol()} ${request.requestMethod()} ${request.url()} from ${request.ip()} accepting $accept with status $statuscode content-type $contentType size $size..."
+}
+
+fun buildCommongLogFormat(request: Request, response: Response): String {
+    val raw = response.raw()
+
+    val size = try {
+        response.body().toByteArray(Charset.forName(raw.characterEncoding)).size.toString()
+    } catch (e: Exception) {
+        "-"
+    }
+
+    // Common Log Format requires strftime format "%d/%b/%Y:%H:%M:%S %z" resulting in stupid "[10/Oct/2000:13:55:36 -0700]". Using ISO instead for now.
+    val datetime = "[${LocalDateTime.now()}]"
+
+    val ip = request.ip()
+    val useridentifier = "-"
+    val userid = "-"
+    val requestline = "\"${request.requestMethod()} ${request.url()} ${request.protocol()}\""
+    val statuscode = raw.status
+
+    // add accept header as additional column
+    val accept = request.headers("accept") ?: "-"
+
+    // add returned content type as additional column
+    val contentType = raw.getHeader("content-type") ?: "-"
+
+    return "$ip $useridentifier $userid $datetime $requestline $statuscode $size $accept $contentType"
+}