Merge branch 'replace-khttp' into 'main'

Replace khttp

Closes #287

See merge request !313

theodolite/build.gradle

@@ -9,7 +9,6 @@ plugins {
 repositories {
     mavenCentral()
     mavenLocal()
-    jcenter()
 }
 
 dependencies {
@@ -26,7 +25,6 @@ dependencies {
     implementation 'org.slf4j:slf4j-simple:1.7.32'
     implementation 'io.github.microutils:kotlin-logging:2.1.16'
     implementation 'org.apache.kafka:kafka-clients:2.8.0'
-    implementation 'khttp:khttp:1.0.0'
     implementation 'net.objecthunter:exp4j:0.4.8'
 
     testImplementation 'io.quarkus:quarkus-junit5'

theodolite/src/main/kotlin/rocks/theodolite/kubernetes/slo/ExternalSloChecker.kt

 package rocks.theodolite.kubernetes.slo
 
-import khttp.post
 import mu.KotlinLogging
 import java.net.ConnectException
+import java.net.URI
+import java.net.http.HttpClient
+import java.net.http.HttpRequest
+import java.net.http.HttpResponse.BodyHandlers
+import java.time.Duration
+
 
 /**
  * [SloChecker] that uses an external source for the concrete evaluation.
@@ -15,7 +20,7 @@ class ExternalSloChecker(
 ) : SloChecker {
 
     private val RETRIES = 2
-    private val TIMEOUT = 60.0
+    private val TIMEOUT = Duration.ofSeconds(60)
 
     private val logger = KotlinLogging.logger {}
 
@@ -36,12 +41,19 @@ class ExternalSloChecker(
         ).toJson()
 
         while (counter < RETRIES) {
-            val result = post(externalSlopeURL, data = data, timeout = TIMEOUT)
-            if (result.statusCode != 200) {
+            val request = HttpRequest.newBuilder()
+                    .uri(URI.create(externalSlopeURL))
+                    .POST(HttpRequest.BodyPublishers.ofString(data))
+                    .timeout(TIMEOUT)
+                    .build()
+            val response = HttpClient.newBuilder()
+                    .build()
+                    .send(request, BodyHandlers.ofString())
+            if (response.statusCode() != 200) {
                 counter++
                 logger.error { "Could not reach external SLO checker at $externalSlopeURL." }
             } else {
-                val booleanResult = result.text.toBoolean()
+                val booleanResult = response.body().toBoolean()
                 logger.info { "SLO checker result is: $booleanResult." }
                 return booleanResult
             }

theodolite/src/main/kotlin/rocks/theodolite/kubernetes/slo/MetricFetcher.kt

 package rocks.theodolite.kubernetes.slo
 
 import com.fasterxml.jackson.databind.ObjectMapper
-import khttp.get
-import khttp.responses.Response
 import mu.KotlinLogging
 import java.net.ConnectException
+import java.net.URI
+import java.net.http.HttpClient
+import java.net.http.HttpRequest
+import java.net.http.HttpResponse
 import java.time.Duration
 import java.time.Instant
 
@@ -18,7 +20,7 @@ private val logger = KotlinLogging.logger {}
  */
 class MetricFetcher(private val prometheusURL: String, private val offset: Duration) {
     private val RETRIES = 2
-    private val TIMEOUT = 60.0
+    private val TIMEOUT = Duration.ofSeconds(60)
 
     /**
      * Tries to fetch a metric by a query to a Prometheus server.
@@ -36,26 +38,27 @@ class MetricFetcher(private val prometheusURL: String, private val offset: Durat
         val offsetEnd = end.minus(offset)
 
         var counter = 0
-        val parameter = mapOf(
-            "query" to query,
-            "start" to offsetStart.toString(),
-            "end" to offsetEnd.toString(),
-            "step" to "5s"
-        )
 
         while (counter < RETRIES) {
             logger.info { "Request collected metrics from Prometheus for interval [$offsetStart,$offsetEnd]." }
-            val response = get("$prometheusURL/api/v1/query_range", params = parameter, timeout = TIMEOUT)
-            if (response.statusCode != 200) {
-                val message = response.jsonObject.toString()
+            val request = HttpRequest.newBuilder()
+                    .uri(URI.create("$prometheusURL/api/v1/query_range?query=$query&start=$offsetStart&end=$offsetEnd&step=5s"))
+                    .GET()
+                    .timeout(TIMEOUT)
+                    .build()
+            val response = HttpClient.newBuilder()
+                    .build()
+                    .send(request, HttpResponse.BodyHandlers.ofString())
+            if (response.statusCode() != 200) {
+                val message = response.body()
                 logger.warn { "Could not connect to Prometheus: $message. Retry $counter/$RETRIES." }
                 counter++
             } else {
-                val values = parseValues(response)
+                val values = parseValues(response.body())
                 if (values.data?.result.isNullOrEmpty()) {
                     throw NoSuchFieldException("Empty query result: $values between for query '$query' in interval [$offsetStart,$offsetEnd] .")
                 }
-                return parseValues(response)
+                return parseValues(response.body())
             }
         }
         throw ConnectException("No answer from Prometheus received.")
@@ -66,9 +69,9 @@ class MetricFetcher(private val prometheusURL: String, private val offset: Durat
      * @param values Response from Prometheus.
      * @return a [PrometheusResponse]
      */
-    private fun parseValues(values: Response): PrometheusResponse {
+    private fun parseValues(values: String): PrometheusResponse {
         return ObjectMapper().readValue<PrometheusResponse>(
-            values.jsonObject.toString(),
+            values,
             PrometheusResponse::class.java
         )
     }