health endpoint (#282)

server/src/main/scala/za/co/absa/atum/server/api/http/Endpoints.scala

@@ -21,7 +21,7 @@ import sttp.tapir.generic.auto.schemaForCaseClass
 import sttp.tapir.json.circe.jsonBody
 import sttp.tapir.ztapir._
 import za.co.absa.atum.model.dto._
-import za.co.absa.atum.server.model.ErrorResponse
+import za.co.absa.atum.server.model.{ErrorResponse, StatusResponse}
 import za.co.absa.atum.server.model.SuccessResponse._
 import sttp.tapir.{PublicEndpoint, Validator, endpoint}
 import za.co.absa.atum.server.api.http.ApiPaths.{Health, ZioMetrics, _}
@@ -177,7 +177,7 @@ trait Endpoints extends BaseEndpoints {
     endpoint.get.in(ZioMetrics).out(stringBody)
   }
 
-  protected val healthEndpoint: PublicEndpoint[Unit, Unit, Unit, Any] =
-    endpoint.get.in(Health)
+  protected val healthEndpoint: PublicEndpoint[Unit, Unit, StatusResponse, Any] =
+    endpoint.get.in(Health).out(jsonBody[StatusResponse].example(StatusResponse.up))
 
 }

server/src/main/scala/za/co/absa/atum/server/api/http/Routes.scala

@@ -27,7 +27,7 @@ import sttp.tapir.ztapir._
 import za.co.absa.atum.model.dto.{AdditionalDataDTO, AdditionalDataPatchDTO, CheckpointV2DTO, PartitioningWithIdDTO}
 import za.co.absa.atum.server.api.controller.{CheckpointController, FlowController, PartitioningController}
 import za.co.absa.atum.server.config.{HttpMonitoringConfig, JvmMonitoringConfig}
-import za.co.absa.atum.server.model.ErrorResponse
+import za.co.absa.atum.server.model.{ErrorResponse, StatusResponse}
 import za.co.absa.atum.server.model.SuccessResponse._
 import zio._
 import zio.interop.catz._
@@ -103,7 +103,7 @@ trait Routes extends Endpoints with ServerOptions {
           PartitioningController.getFlowPartitionings(flowId, limit, offset)
         }
       ),
-      createServerEndpoint(healthEndpoint, (_: Unit) => ZIO.unit)
+      createServerEndpoint(healthEndpoint, (_: Unit) => ZIO.succeed(StatusResponse.up))
     )
     ZHttp4sServerInterpreter[HttpEnv.Env](http4sServerOptions(metricsInterceptorOption)).from(endpoints).toRoutes
   }
@@ -125,6 +125,7 @@ trait Routes extends Endpoints with ServerOptions {
       //      getPartitioningMeasuresEndpointV2,
       //      getFlowPartitioningsEndpointV2,
       //      getPartitioningMainFlowEndpointV2
+      healthEndpoint
     )
     ZHttp4sServerInterpreter[HttpEnv.Env](http4sServerOptions(None))
       .from(SwaggerInterpreter().fromEndpoints[HttpEnv.F](endpoints, "Atum API", "1.0"))

server/src/main/scala/za/co/absa/atum/server/model/StatusResponse.scala

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2021 ABSA Group Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package za.co.absa.atum.server.model
+
+case class StatusResponse(status: String, message: String)
+
+object StatusResponse {
+
+  import io.circe.generic.semiauto._
+
+  implicit val encoder: io.circe.Encoder[StatusResponse] = deriveEncoder
+  implicit val decoder: io.circe.Decoder[StatusResponse] = deriveDecoder
+
+  def up: StatusResponse = {
+    StatusResponse(
+      status = "UP",
+      message = "Atum server is up and running"
+    )
+  }
+
+}

server/src/test/scala/za/co/absa/atum/server/api/http/HealthEndpointUnitTests.scala

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2021 ABSA Group Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package za.co.absa.atum.server.api.http
+
+import sttp.client3.circe.asJson
+import sttp.client3.testing.SttpBackendStub
+import sttp.client3.{UriContext, basicRequest}
+import sttp.model.StatusCode
+import sttp.tapir.server.stub.TapirStubInterpreter
+import sttp.tapir.ztapir.{RIOMonadError, RichZEndpoint}
+import za.co.absa.atum.server.model.StatusResponse
+import zio.test.Assertion.equalTo
+import zio.test.{Spec, TestEnvironment, ZIOSpecDefault, assertZIO}
+import zio.{Scope, ZIO}
+
+object HealthEndpointUnitTests extends ZIOSpecDefault with Endpoints {
+
+  private val healthServerEndpoint = healthEndpoint.zServerLogic((_: Unit) => ZIO.succeed(StatusResponse.up))
+
+  override def spec: Spec[TestEnvironment with Scope, Any] = {
+    val backendStub = TapirStubInterpreter(SttpBackendStub.apply(new RIOMonadError[Any]))
+      .whenServerEndpoint(healthServerEndpoint)
+      .thenRunLogic()
+      .backend()
+
+    suite("HealthEndpointSuite")(
+      test("Returns expected StatusResponse") {
+        val request = basicRequest
+          .get(uri"https://test.com/health")
+          .response(asJson[StatusResponse])
+
+        val response = request.send(backendStub)
+
+        val body = response.map(_.body)
+        val statusCode = response.map(_.code)
+
+        assertZIO(body <&> statusCode)(
+          equalTo(Right(StatusResponse.up), StatusCode.Ok)
+        )
+      }
+    )
+  }
+}