Allow setting a custom labelSelector in the k8s health api (#119)

Author: ghostdogpr

health-k8s/src/main/scala/com/devsisters/shardcake/K8sConfig.scala

@@ -1,16 +1,22 @@
 package com.devsisters.shardcake
 
-import com.coralogix.zio.k8s.client.model.K8sNamespace
+import com.coralogix.zio.k8s.client.model.{ K8sNamespace, LabelSelector }
 import zio._
 
 /**
  * Configuration for K8sPodsHealth
  * @param cacheSize how many items we keep in the pod status cache
  * @param cacheDuration how long we keep items in the pod status cache
  * @param namespace namespace to query pods from (if None, query all namespaces)
+ * @param labelSelector allows to filter pods by k8s labels
  */
-case class K8sConfig(cacheSize: Int, cacheDuration: Duration, namespace: Option[K8sNamespace])
+case class K8sConfig(
+  cacheSize: Int,
+  cacheDuration: Duration,
+  namespace: Option[K8sNamespace],
+  labelSelector: Option[LabelSelector]
+)
 
 object K8sConfig {
-  val default: K8sConfig = K8sConfig(500, 3 seconds, None)
+  val default: K8sConfig = K8sConfig(500, 3 seconds, None, None)
 }

health-k8s/src/main/scala/com/devsisters/shardcake/K8sPodsHealth.scala

@@ -14,7 +14,7 @@ import com.coralogix.zio.k8s.client.{
   Unauthorized,
   UndefinedField
 }
-import com.coralogix.zio.k8s.client.model.FieldSelector
+import com.coralogix.zio.k8s.client.model.{ FieldSelector, LabelSelector }
 import com.coralogix.zio.k8s.client.v1.pods.Pods
 import com.coralogix.zio.k8s.model.pkg.apis.meta.v1.Status
 import com.devsisters.shardcake.interfaces.PodsHealth
@@ -42,7 +42,8 @@ object K8sPodsHealth {
                           .getAll(
                             config.namespace,
                             1,
-                            Some(FieldSelector.FieldEquals(Chunk("status", "podIP"), podAddress.host))
+                            Some(FieldSelector.FieldEquals(Chunk("status", "podIP"), podAddress.host)),
+                            config.labelSelector
                           )
                           .runHead
                           .map(_.isDefined)