supplemental api health check endpoint (#122)

supplemental-api-function-app/src/main/java/gov/cdc/ocio/supplementalapi/FunctionJavaWrappers.java

@@ -3,11 +3,23 @@
 import java.util.*;
 import com.microsoft.azure.functions.annotation.*;
 import com.microsoft.azure.functions.*;
+import gov.cdc.ocio.supplementalapi.functions.HealthCheckFunction;
 import gov.cdc.ocio.supplementalapi.functions.StatusForDestinationFunction;
 import gov.cdc.ocio.supplementalapi.functions.StatusForTguidFunction;
 
 public class FunctionJavaWrappers {
 
+    @FunctionName("HealthCheck")
+    public HttpResponseMessage healthCheck(
+            @HttpTrigger(
+                    name = "req",
+                    methods = {HttpMethod.GET},
+                    route = "health",
+                    authLevel = AuthorizationLevel.FUNCTION) HttpRequestMessage<Optional<String>> request,
+            final ExecutionContext context) {
+        return new HealthCheckFunction().run(request, context);
+    }
+
     @FunctionName("StatusForTguid")
     public HttpResponseMessage statusForTguid(
             @HttpTrigger(

supplemental-api-function-app/src/main/kotlin/gov/cdc/ocio/supplementalapi/functions/HealthCheckFunction.kt

@@ -0,0 +1,38 @@
+package gov.cdc.ocio.supplementalapi.functions
+
+import com.azure.cosmos.models.CosmosQueryRequestOptions
+import com.microsoft.azure.functions.ExecutionContext
+import com.microsoft.azure.functions.HttpRequestMessage
+import com.microsoft.azure.functions.HttpResponseMessage
+import com.microsoft.azure.functions.HttpStatus
+import gov.cdc.ocio.supplementalapi.cosmos.CosmosClientManager
+import gov.cdc.ocio.supplementalapi.model.Item
+import java.util.*
+
+
+class HealthCheckFunction {
+
+    fun run(
+        request: HttpRequestMessage<Optional<String>>,
+        context: ExecutionContext
+    ): HttpResponseMessage {
+
+        val cosmosClient = CosmosClientManager.getCosmosClient()
+
+        val databaseName = System.getenv("CosmosDbDatabaseName")
+        val containerName = System.getenv("CosmosDbContainerName")
+
+        val cosmosDB = cosmosClient.getDatabase(databaseName)
+        val container = cosmosDB.getContainer(containerName)
+
+        val sqlQuery = "select * from $containerName t OFFSET 0 LIMIT 1"
+        val items = container.queryItems(
+            sqlQuery, CosmosQueryRequestOptions(),
+            Item::class.java
+        )
+
+        return request
+            .createResponseBuilder(HttpStatus.OK)
+            .build()
+    }
+}