introduce app configuration

Author: ianfnelson

.env.example

@@ -7,10 +7,9 @@ AZURE_WEB_JOBS_STORAGE=UseDevelopmentStorage=true
 DatabaseConnectionString=Server=${DATABASE_HOST};Database=${DATABASE_NAME};User Id=${DATABASE_USER};Password=${DATABASE_PASSWORD};TrustServerCertificate=True
 AzureWebJobsStorage=UseDevelopmentStorage=true
 FUNCTIONS_WORKER_RUNTIME=dotnet-isolated
-MailboxId=X26ABC1
 MeshSharedKey=TestKey
 MeshPassword=password
-NBSSMailBoxId=X26ABC1
+NbssMailboxId=X26ABC1
 MeshApiBaseUrl=http://localhost:8700/messageexchange
 ASPNETCORE_ENVIRONMENT=Development
 FileDiscoveryTimerExpression=*/5 * * * *

src/ServiceLayer.Mesh/Configuration/AppConfiguration.cs

@@ -0,0 +1,18 @@
+namespace ServiceLayer.Mesh.Configuration;
+
+public class AppConfiguration : IFileDiscoveryFunctionConfiguration
+{
+    public string NbssMeshMailboxId => GetRequired("NbssMailboxId");
+
+    private static string GetRequired(string key)
+    {
+        var value = Environment.GetEnvironmentVariable(key);
+
+        if (string.IsNullOrEmpty(value))
+        {
+            throw new InvalidOperationException($"Environment variable '{key}' is not set or is empty.");
+        }
+
+        return value;
+    }
+}

src/ServiceLayer.Mesh/Configuration/IFileDiscoveryFunctionConfiguration.cs

@@ -0,0 +1,6 @@
+namespace ServiceLayer.Mesh.Configuration;
+
+public interface IFileDiscoveryFunctionConfiguration
+{
+    string NbssMeshMailboxId { get; }
+}

src/ServiceLayer.Mesh/Functions/FileDiscoveryFunction.cs

@@ -2,6 +2,7 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using NHS.MESH.Client.Contracts.Services;
+using ServiceLayer.Mesh.Configuration;
 using ServiceLayer.Mesh.Data;
 using ServiceLayer.Mesh.Messaging;
 using ServiceLayer.Mesh.Models;
@@ -10,6 +11,7 @@ namespace ServiceLayer.Mesh.Functions
 {
     public class FileDiscoveryFunction(
         ILogger<FileDiscoveryFunction> logger,
+        IFileDiscoveryFunctionConfiguration configuration,
         IMeshInboxService meshInboxService,
         ServiceLayerDbContext serviceLayerDbContext,
         IFileExtractQueueClient fileExtractQueueClient)
@@ -19,11 +21,7 @@ public async Task Run([TimerTrigger("%FileDiscoveryTimerExpression%")] TimerInfo
         {
             logger.LogInformation($"DiscoveryFunction started at: {DateTime.Now}");
 
-            // TODO - abstract this out into an injectable configuration interface for testing purposes
-            var mailboxId = Environment.GetEnvironmentVariable("NBSSMailBoxId")
-                ?? throw new InvalidOperationException($"Environment variable 'NBSSMailBoxId' is not set or is empty.");
-
-            var response = await meshInboxService.GetMessagesAsync(mailboxId);
+            var response = await meshInboxService.GetMessagesAsync(configuration.NbssMeshMailboxId);
 
             foreach (var messageId in response.Response.Messages)
             {
@@ -38,7 +36,7 @@ public async Task Run([TimerTrigger("%FileDiscoveryTimerExpression%")] TimerInfo
                     {
                         FileId = messageId,
                         FileType = MeshFileType.NbssAppointmentEvents,
-                        MailboxId = mailboxId,
+                        MailboxId = configuration.NbssMeshMailboxId,
                         Status = MeshFileStatus.Discovered,
                         FirstSeenUtc = DateTime.UtcNow,
                         LastUpdatedUtc = DateTime.UtcNow

src/ServiceLayer.Mesh/Program.cs

@@ -7,6 +7,7 @@
 using NHS.MESH.Client;
 using ServiceLayer.Mesh.Data;
 using Azure.Storage.Blobs;
+using ServiceLayer.Mesh.Configuration;
 using ServiceLayer.Mesh.Messaging;
 
 var host = new HostBuilder()
@@ -19,7 +20,7 @@
         // MESH Client config
         services
             .AddMeshClient(_ => _.MeshApiBaseUrl = Environment.GetEnvironmentVariable("MeshApiBaseUrl"))
-            .AddMailbox(Environment.GetEnvironmentVariable("NBSSMailBoxId"), new NHS.MESH.Client.Configuration.MailboxConfiguration
+            .AddMailbox(Environment.GetEnvironmentVariable("NbssMailboxId"), new NHS.MESH.Client.Configuration.MailboxConfiguration
             {
                 Password = Environment.GetEnvironmentVariable("MeshPassword"),
                 SharedKey = Environment.GetEnvironmentVariable("MeshSharedKey"),
@@ -57,6 +58,8 @@
                 Environment.GetEnvironmentVariable("AzureWebJobsStorage"),
                 Environment.GetEnvironmentVariable("BlobContainerName"));
         });
+
+        services.AddTransient<IFileDiscoveryFunctionConfiguration, AppConfiguration>();
     });
 
 

tests/ServiceLayer.Mesh.Tests/Functions/FileDiscoveryFunctionTests.cs

@@ -3,6 +3,7 @@
 using Moq;
 using NHS.MESH.Client.Contracts.Services;
 using NHS.MESH.Client.Models;
+using ServiceLayer.Mesh.Configuration;
 using ServiceLayer.Mesh.Data;
 using ServiceLayer.Mesh.Functions;
 using ServiceLayer.Mesh.Messaging;
@@ -32,11 +33,12 @@ public FileDiscoveryFunctionTests()
 
         _dbContext = new ServiceLayerDbContext(options);
 
-        Environment.SetEnvironmentVariable("NBSSMailBoxId", "test-mailbox");
-        Environment.SetEnvironmentVariable("QueueUrl", "https://fakestorageaccount.queue.core.windows.net/testqueue");
+        var functionConfiguration = new Mock<IFileDiscoveryFunctionConfiguration>();
+        functionConfiguration.Setup(c => c.NbssMeshMailboxId).Returns("test-mailbox");
 
         _function = new FileDiscoveryFunction(
             _loggerMock.Object,
+            functionConfiguration.Object,
             _meshInboxServiceMock.Object,
             _dbContext,
             _queueClientMock.Object