Only expose when there is a URI & provide docs for legacy approach (#…

…1048)
tomkerkhove · May 24, 2020 · f29318a · f29318a
1 parent f731a69
commit f29318a
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Showing 2 changed files with 19 additions and 12 deletions.
diff --git a/src/Promitor.Agents.Scraper/Extensions/IApplicationBuilderExtensions.cs b/src/Promitor.Agents.Scraper/Extensions/IApplicationBuilderExtensions.cs
@@ -32,11 +32,14 @@ public static IApplicationBuilder UseMetricSinks(this IApplicationBuilder app, I
         /// <param name="scrapeEndpointPath">Path where the scrape endpoint will be exposed</param>
         public static IApplicationBuilder AddPrometheusScraperMetricSink(this IApplicationBuilder app, string scrapeEndpointPath)
         {
-            app.UsePrometheusServer(prometheusOptions =>
+            if (string.IsNullOrWhiteSpace(scrapeEndpointPath) == false)
             {
-                prometheusOptions.MapPath = scrapeEndpointPath;
-                prometheusOptions.UseDefaultCollectors = false;
-            });
+                app.UsePrometheusServer(prometheusOptions =>
+                {
+                    prometheusOptions.MapPath = scrapeEndpointPath;
+                    prometheusOptions.UseDefaultCollectors = false;
+                });
+            }
 
             return app;
         }

diff --git a/src/Promitor.Agents.Scraper/Startup.cs b/src/Promitor.Agents.Scraper/Startup.cs
@@ -14,7 +14,6 @@
 using Promitor.Agents.Scraper.Validation;
 using Promitor.Core.Scraping.Configuration.Serialization.v1.Mapping;
 using Promitor.Integrations.AzureMonitor.Logging;
-using Promitor.Integrations.Sinks.Prometheus.Configuration;
 using Serilog;
 using Swashbuckle.AspNetCore.SwaggerUI;
 
@@ -24,19 +23,19 @@ public class Startup : AgentStartup
     {
         private const string ApiName = "Promitor - Scraper API";
         private const string ComponentName = "Promitor Scraper";
-        private readonly string _prometheusBaseUriPath;
+        private readonly string _legacyPrometheusUriPath;
 
         public Startup(IConfiguration configuration)
         : base(configuration)
         {
-            var scrapeEndpointConfiguration = configuration.GetSection("prometheus:scrapeEndpoint").Get<ScrapeEndpointConfiguration>();
-            _prometheusBaseUriPath = scrapeEndpointConfiguration.BaseUriPath;
+            var runtimeConfiguration = configuration.Get<ScraperRuntimeConfiguration>();
+            _legacyPrometheusUriPath = runtimeConfiguration?.Prometheus?.ScrapeEndpoint?.BaseUriPath;
         }
 
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
-            string openApiDescription = BuildOpenApiDescription(Configuration);
+            string openApiDescription = BuildOpenApiDescription(Configuration, _legacyPrometheusUriPath);
             services.UseWebApi()
                 .AddHttpCorrelation()
                 .AddAutoMapper(typeof(V1MappingProfile).Assembly)
@@ -65,7 +64,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                .UseHttpCorrelation()
                .UseRouting()
                .UseMetricSinks(Configuration)
-               .AddPrometheusScraperMetricSink(_prometheusBaseUriPath) // Deprecated and will be gone in 2.0
+               .AddPrometheusScraperMetricSink(_legacyPrometheusUriPath) // Deprecated and will be gone in 2.0
                .ExposeOpenApiUi() // New Swagger UI
                .ExposeOpenApiUi(ApiName, swaggerUiOptions =>
                {
@@ -100,14 +99,19 @@ protected override LoggerConfiguration FilterTelemetry(LoggerConfiguration logge
             return standardConfiguration;
         }
 
-        private string BuildOpenApiDescription(IConfiguration configuration)
+        private string BuildOpenApiDescription(IConfiguration configuration, string legacyPrometheusUriPath)
         {
             var metricSinkConfiguration = configuration.GetSection("metricSinks").Get<MetricSinkConfiguration>();
 
             var openApiDescriptionBuilder = new StringBuilder();
             openApiDescriptionBuilder.Append("Collection of APIs to manage the Promitor Scraper.\r\n\r\n");
             openApiDescriptionBuilder.AppendLine("Configured metric sinks are:\r\n");
 
+            if (string.IsNullOrWhiteSpace(legacyPrometheusUriPath) == false)
+            {
+                openApiDescriptionBuilder.AppendLine($"<li>Legacy Prometheus scrape endpoint is exposed at <a href=\"./../..{legacyPrometheusUriPath}\" target=\"_blank\">{legacyPrometheusUriPath}</a></li>");
+            }
+
             if (metricSinkConfiguration.PrometheusScrapingEndpoint != null)
             {
                 var prometheusScrapingBaseUri = metricSinkConfiguration.PrometheusScrapingEndpoint.BaseUriPath;
@@ -118,7 +122,7 @@ private string BuildOpenApiDescription(IConfiguration configuration)
             {
                 openApiDescriptionBuilder.AppendLine($"<li>StatsD server located on {metricSinkConfiguration.Statsd.Host}:{metricSinkConfiguration.Statsd.Port}</li>");
             }
-            
+
             return openApiDescriptionBuilder.ToString();
         }
     }