Ref #29480: Add missing file

Author: LEDfan

src/main/kotlin/eu/openanalytics/shinyproxyoperator/components/IngressPatcher.kt

@@ -0,0 +1,66 @@
+/**
+ * ShinyProxy-Operator
+ *
+ * Copyright (C) 2021-2023 Open Analytics
+ *
+ * ===========================================================================
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Apache License as published by
+ * The Apache Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * Apache License for more details.
+ *
+ * You should have received a copy of the Apache License
+ * along with this program.  If not, see <http://www.apache.org/licenses/>
+ */
+package eu.openanalytics.shinyproxyoperator.components
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory
+import com.fasterxml.jackson.datatype.jsr353.JSR353Module
+import io.fabric8.kubernetes.api.model.HTTPGetAction
+import io.fabric8.kubernetes.api.model.IntOrString
+import io.fabric8.kubernetes.api.model.PodTemplateSpec
+import io.fabric8.kubernetes.api.model.networking.v1.Ingress
+import mu.KotlinLogging
+import javax.json.JsonPatch
+import javax.json.JsonStructure
+
+class IngressPatcher {
+    private val mapper = ObjectMapper(YAMLFactory())
+    private val logger = KotlinLogging.logger { }
+
+    init {
+        mapper.registerModule(JSR353Module())
+    }
+
+    /**
+     * Applies a JsonPatch to the given Ingress.
+     */
+    fun patch(ingress: Ingress, patch: JsonPatch?): Ingress {
+        if (patch == null) {
+            return ingress
+        }
+
+        logger.debug { "Original Ingress (before applying patches): ${mapper.writeValueAsString(ingress)}" }
+
+        // 1. convert PodTemplate to javax.json.JsonValue object.
+        // This conversion does not actually convert to a string, but some internal
+        // representation of Jackson.
+        val podAsJsonValue: JsonStructure = mapper.convertValue(ingress, JsonStructure::class.java)
+        // 2. apply patch
+        val patchedPodAsJsonValue: JsonStructure = patch.apply(podAsJsonValue)
+        // 3. convert back to a PodTemplate
+        val patchesIngress = mapper.convertValue(patchedPodAsJsonValue, Ingress::class.java)
+
+        logger.debug { "Patched Ingress (after applying patches): ${mapper.writeValueAsString(patchesIngress)}" }
+
+        return patchesIngress
+    }
+
+}