Fixes from review:

* Caching still doesn't work !?!?!

samples/EchoTranslationEngine/TranslationEngineServiceV1.cs

@@ -1,10 +1,16 @@
 namespace EchoTranslationEngine;
 
-public class TranslationEngineServiceV1(BackgroundTaskQueue taskQueue, HealthCheckService healthCheckService) : TranslationEngineApi.TranslationEngineApiBase
+public class TranslationEngineServiceV1 : TranslationEngineApi.TranslationEngineApiBase
 {
     private static readonly Empty Empty = new();
-    private readonly BackgroundTaskQueue _taskQueue = taskQueue;
-    private readonly HealthCheckService _healthCheckService = healthCheckService;
+    private readonly BackgroundTaskQueue _taskQueue;
+    private readonly HealthCheckService _healthCheckService;
+
+    public TranslationEngineServiceV1(BackgroundTaskQueue taskQueue, HealthCheckService healthCheckService)
+    {
+        _taskQueue = taskQueue;
+        _healthCheckService = healthCheckService;
+    }
 
     public override Task<Empty> Create(CreateRequest request, ServerCallContext context)
     {

src/Serval.ApiServer/Controllers/StatusController.cs

@@ -32,7 +32,7 @@ IConfiguration configuration
     /// <response code="403">The authenticated client cannot perform the operation</response>
     [Authorize(Scopes.ReadStatus)]
     [HttpGet("health")]
-    [OutputCache(PolicyName = "CacheHealthStatus")]
+    [OutputCache]
     [ProducesResponseType(typeof(HealthReportDto), (int)HttpStatusCode.OK)]
     [ProducesResponseType(typeof(void), StatusCodes.Status401Unauthorized)]
     [ProducesResponseType(typeof(void), StatusCodes.Status403Forbidden)]
@@ -47,10 +47,10 @@ public async Task<ActionResult<HealthReportDto>> GetHealthAsync()
     /// </summary>
     /// <remarks>Provides an indication about the health of the API</remarks>
     /// <response code="200">The API health status</response>
-    [HttpGet("health-public")]
-    [OutputCache(PolicyName = "CacheHealthStatus")]
+    [HttpGet("ping")]
+    [OutputCache]
     [ProducesResponseType(typeof(HealthReportDto), (int)HttpStatusCode.OK)]
-    public async Task<ActionResult<HealthReportDto>> GetPublicHealthAsync()
+    public async Task<ActionResult<HealthReportDto>> GetPingAsync()
     {
         var report = await _healthCheckService.CheckHealthAsync();
         HealthReportDto reportDto = Map(report);

src/Serval.ApiServer/Startup.cs

@@ -16,6 +16,8 @@ public void ConfigureServices(IServiceCollection services)
     {
         services.AddRouting(o => o.LowercaseUrls = true);
 
+        services.AddOutputCache();
+
         services
             .AddControllers()
             .AddJsonOptions(o =>
@@ -42,9 +44,10 @@ public void ConfigureServices(IServiceCollection services)
             });
         services.AddHealthChecks().AddIdentityServer(new Uri(authority), name: "Auth0");
 
-        string DataFilesDir = Configuration!.GetSection(DataFileOptions.Key)!.GetValue<string>("FilesDirectory")!;
+        var dataFileOptions = new DataFileOptions();
+        Configuration.GetSection(DataFileOptions.Key).Bind(dataFileOptions);
         // find drive letter for DataFilesDir
-        string driveLetter = Path.GetPathRoot(DataFilesDir)![..1];
+        string driveLetter = Path.GetPathRoot(dataFileOptions.FilesDirectory)![..1];
 
         // add health check for disk storage capacity
         services
@@ -55,11 +58,6 @@ public void ConfigureServices(IServiceCollection services)
                 HealthStatus.Degraded
             );
 
-        services.AddOutputCache(options =>
-        {
-            options.AddPolicy("CacheHealthStatus", builder => builder.Expire(TimeSpan.FromSeconds(10)));
-        });
-
         services.AddAuthorization(o =>
         {
             foreach (string scope in Scopes.All)
@@ -206,16 +204,16 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
 
         app.UseRouting();
         app.UseAuthorization();
-        app.UseOutputCache();
         app.UseEndpoints(x =>
         {
             x.MapControllers();
             x.MapServalTranslationServices();
             x.MapHangfireDashboard();
             x.MapHealthChecks("/health", new HealthCheckOptions { ResponseWriter = WriteHealthCheckResponse.Generate });
-            ;
         });
 
+        app.UseOutputCache();
+
         app.UseOpenApi(o =>
         {
             o.PostProcess = (document, request) =>

src/Serval.ApiServer/Usings.cs

@@ -1,5 +1,7 @@
 global using System.Net;
 global using System.Security.Claims;
+global using System.Text;
+global using System.Text.Json;
 global using System.Text.Json.Serialization;
 global using Asp.Versioning;
 global using Hangfire;
@@ -30,4 +32,3 @@
 global using Serval.Shared.Controllers;
 global using Serval.Shared.Models;
 global using Serval.Shared.Services;
-global using Serval.Shared.Utils;

src/Serval.Shared/Utils/WriteHealthCheckResponse.cs → src/Serval.ApiServer/WriteHealthCheckResponse.cs

@@ -1,4 +1,4 @@
-namespace Serval.Shared.Utils;
+namespace Serval.ApiServer;
 
 public class WriteHealthCheckResponse
 {

src/Serval.Client/Client.g.cs

@@ -31,7 +31,7 @@ public partial interface IStatusClient
 
         /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
         /// <exception cref="ServalApiException">A server side error occurred.</exception>
-        System.Threading.Tasks.Task<HealthReport> GetPublicHealthAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        System.Threading.Tasks.Task<HealthReport> GetPingAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
 
         /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
         /// <exception cref="ServalApiException">A server side error occurred.</exception>
@@ -153,10 +153,10 @@ public string BaseUrl
 
         /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
         /// <exception cref="ServalApiException">A server side error occurred.</exception>
-        public virtual async System.Threading.Tasks.Task<HealthReport> GetPublicHealthAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        public virtual async System.Threading.Tasks.Task<HealthReport> GetPingAsync(System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
         {
             var urlBuilder_ = new System.Text.StringBuilder();
-            urlBuilder_.Append(BaseUrl != null ? BaseUrl.TrimEnd('/') : "").Append("/status/health-public");
+            urlBuilder_.Append(BaseUrl != null ? BaseUrl.TrimEnd('/') : "").Append("/status/ping");
 
             var client_ = _httpClient;
             var disposeClient_ = false;

src/Serval.Grpc/Protos/serval/translation/v1/engine.proto

@@ -105,10 +105,9 @@ message TranslationResult {
 }
 
 message HealthCheckResponse {
-    HealthCheckStatus Status = 1;
-    string Duration = 2;
-    map<string, string> Data = 3;
-    optional string Exception = 4;
+    HealthCheckStatus status = 1;
+    map<string, string> data = 2;
+    optional string error = 3;
 }
 
 message WordGraphArc {
@@ -160,7 +159,7 @@ enum TranslationSource {
 }
 
 enum HealthCheckStatus {
-    Unhealthy = 0;
-    Degraded = 1;
-    Healthy = 2;
+    UNHEALTHY = 0;
+    DEGRADED = 1;
+    HEALTHY = 2;
 }

src/Serval.Grpc/Utils/WriteGrpcHealthCheckResponse.cs

@@ -20,12 +20,8 @@ public static HealthCheckResponse Generate(HealthReport healthReport)
                     healthCheckResultException += $"\n{entry.Key}: {entry.Value.Exception}";
         }
         // Assemble response
-        HealthCheckResponse healthCheckReponse = new HealthCheckResponse
-        {
-            Status = (HealthCheckStatus)healthReport.Status,
-            Duration = healthReport.TotalDuration.ToString(),
-            Exception = healthCheckResultException ?? ""
-        };
+        HealthCheckResponse healthCheckReponse =
+            new() { Status = (HealthCheckStatus)healthReport.Status, Error = healthCheckResultException ?? "" };
         foreach (KeyValuePair<string, string> entry in healthCheckResultData)
         {
             healthCheckReponse.Data.Add(entry.Key, entry.Value);

src/Serval.Shared/Configuration/IServalBuilderExtensions.cs

@@ -43,10 +43,11 @@ public static IServalBuilder AddMongoDataAccess(
         Action<IMongoDataAccessConfigurator> configure
     )
     {
-        builder.Services.AddMongoDataAccess(builder.Configuration!.GetConnectionString("Mongo")!, "Serval", configure);
-        builder
-            .Services.AddHealthChecks()
-            .AddMongoDb(builder.Configuration!.GetConnectionString("Mongo")!, name: "Mongo");
+        var mongoConnectionString =
+            builder.Configuration?.GetConnectionString("Mongo")
+            ?? throw new Exception("Mongo connection string not configured");
+        builder.Services.AddMongoDataAccess(mongoConnectionString, "Serval", configure);
+        builder.Services.AddHealthChecks().AddMongoDb(mongoConnectionString, name: "Mongo");
         return builder;
     }
 }

src/Serval.Shared/Controllers/ServiceUnavailableExceptionFilter.cs

@@ -16,11 +16,7 @@ public override void OnException(ExceptionContext context)
             || (context.Exception is RpcException rpcEx && rpcEx.StatusCode == StatusCode.Unavailable)
         )
         {
-            _logger.Log(
-                LogLevel.Error,
-                "A user tried to access an unavailable service. Exception: \n{Exception}",
-                context.Exception
-            );
+            _logger.Log(LogLevel.Error, context.Exception, "A user tried to access an unavailable service.");
             context.Result = new StatusCodeResult(StatusCodes.Status503ServiceUnavailable);
             context.ExceptionHandled = true;
         }

src/Serval.Translation/Configuration/IServalBuilderExtensions.cs

@@ -26,8 +26,7 @@ public static IServalBuilder AddTranslation(
         builder.Services.AddScoped<IEngineService, EngineService>();
 
         var translationOptions = new TranslationOptions();
-        if (builder.Configuration is not null)
-            builder.Configuration.GetSection(TranslationOptions.Key).Bind(translationOptions);
+        builder.Configuration?.GetSection(TranslationOptions.Key).Bind(translationOptions);
         if (configure is not null)
             configure(translationOptions);
 

src/Serval.Translation/Services/GrpcServiceHealthCheck.cs

@@ -20,21 +20,21 @@ public async Task<HealthCheckResult> CheckHealthAsync(
         var client = _grpcClientFactory.CreateClient<TranslationEngineApi.TranslationEngineApiClient>(
             context.Registration.Name
         );
-        HealthCheckResponse? healthReport = await client.HealthCheckAsync(
+        HealthCheckResponse? healthCheckResponse = await client.HealthCheckAsync(
             new Google.Protobuf.WellKnownTypes.Empty(),
             cancellationToken: cancellationToken
         );
-        if (healthReport is null)
+        if (healthCheckResponse is null)
             return HealthCheckResult.Unhealthy(
                 $"Health check for {context.Registration.Name} failed with response null"
             );
         // map health report to health check result
         HealthCheckResult healthCheckResult =
             new(
-                status: (HealthStatus)healthReport.Status,
+                status: (HealthStatus)healthCheckResponse.Status,
                 description: context.Registration.Name,
-                exception: healthReport.Exception is null ? null : new Exception(healthReport.Exception),
-                data: healthReport.Data.ToDictionary(kvp => kvp.Key, kvp => (object)kvp.Value)
+                exception: healthCheckResponse.Error is null ? null : new Exception(healthCheckResponse.Error),
+                data: healthCheckResponse.Data.ToDictionary(kvp => kvp.Key, kvp => (object)kvp.Value)
             );
         return healthCheckResult;
     }