From 43e1359ef483c899c05bedaac10ada73db5fe1e2 Mon Sep 17 00:00:00 2001
From: Tom Kerkhove <kerkhove.tom@gmail.com>
Date: Fri, 11 Dec 2020 16:58:14 +0100
Subject: [PATCH] Log Prometheus sink URL

Signed-off-by: Tom Kerkhove <kerkhove.tom@gmail.com>
---
 src/Promitor.Agents.Core/AgentStartup.cs                   | 2 +-
 src/Promitor.Agents.Scraper/Docs/Open-Api.xml              | 3 ++-
 .../Extensions/IApplicationBuilderExtensions.cs            | 5 ++++-
 src/Promitor.Agents.Scraper/Startup.cs                     | 7 ++++---
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/Promitor.Agents.Core/AgentStartup.cs b/src/Promitor.Agents.Core/AgentStartup.cs
index 16ea5ff86..25d01efda 100644
--- a/src/Promitor.Agents.Core/AgentStartup.cs
+++ b/src/Promitor.Agents.Core/AgentStartup.cs
@@ -20,7 +20,7 @@ public class AgentStartup
         ///     Constructor
         /// </summary>
         /// <param name="configuration">Configuration of the application</param>
-        public AgentStartup(IConfiguration configuration)
+        protected AgentStartup(IConfiguration configuration)
         {
             Guard.NotNull(configuration, nameof(configuration));
 
diff --git a/src/Promitor.Agents.Scraper/Docs/Open-Api.xml b/src/Promitor.Agents.Scraper/Docs/Open-Api.xml
index 57fcd8593..75aa7a60d 100644
--- a/src/Promitor.Agents.Scraper/Docs/Open-Api.xml
+++ b/src/Promitor.Agents.Scraper/Docs/Open-Api.xml
@@ -41,12 +41,13 @@
             </summary>
             <remarks>Provides information concerning the Promitor Scraper Agent</remarks>
         </member>
-        <member name="M:Promitor.Agents.Scraper.Extensions.IApplicationBuilderExtensions.UseMetricSinks(Microsoft.AspNetCore.Builder.IApplicationBuilder,Microsoft.Extensions.Configuration.IConfiguration)">
+        <member name="M:Promitor.Agents.Scraper.Extensions.IApplicationBuilderExtensions.UseMetricSinks(Microsoft.AspNetCore.Builder.IApplicationBuilder,Microsoft.Extensions.Configuration.IConfiguration,Microsoft.Extensions.Logging.ILogger{Promitor.Agents.Scraper.Startup})">
             <summary>
                 Adds the required metric sinks
             </summary>
             <param name="app">Application Builder</param>
             <param name="configuration">Configuration of the scraper agent</param>
+            <param name="logger"></param>
         </member>
         <member name="M:Promitor.Agents.Scraper.Extensions.ObjectExtensions.Clone``1(``0)">
             <summary>
diff --git a/src/Promitor.Agents.Scraper/Extensions/IApplicationBuilderExtensions.cs b/src/Promitor.Agents.Scraper/Extensions/IApplicationBuilderExtensions.cs
index 80c8b6b5b..b68880c4a 100644
--- a/src/Promitor.Agents.Scraper/Extensions/IApplicationBuilderExtensions.cs
+++ b/src/Promitor.Agents.Scraper/Extensions/IApplicationBuilderExtensions.cs
@@ -1,5 +1,6 @@
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging;
 using Prometheus.Client.AspNetCore;
 using Promitor.Agents.Scraper.Configuration.Sinks;
 
@@ -14,13 +15,15 @@ public static class IApplicationBuilderExtensions
         /// </summary>
         /// <param name="app">Application Builder</param>
         /// <param name="configuration">Configuration of the scraper agent</param>
-        public static IApplicationBuilder UseMetricSinks(this IApplicationBuilder app, IConfiguration configuration)
+        /// <param name="logger"></param>
+        public static IApplicationBuilder UseMetricSinks(this IApplicationBuilder app, IConfiguration configuration, ILogger<Startup> logger)
         {
             var metricSinkConfiguration = configuration.GetSection("metricSinks").Get<MetricSinkConfiguration>();
             if (metricSinkConfiguration?.PrometheusScrapingEndpoint != null)
             {
                 if (string.IsNullOrWhiteSpace(metricSinkConfiguration.PrometheusScrapingEndpoint.BaseUriPath) == false)
                 {
+                    logger.LogInformation("Adding Prometheus sink to expose on {PrometheusUrl}", metricSinkConfiguration.PrometheusScrapingEndpoint.BaseUriPath);
                     app.UsePrometheusServer(prometheusOptions =>
                     {
                         prometheusOptions.MapPath = metricSinkConfiguration.PrometheusScrapingEndpoint.BaseUriPath;
diff --git a/src/Promitor.Agents.Scraper/Startup.cs b/src/Promitor.Agents.Scraper/Startup.cs
index b29d8fade..9628cc541 100644
--- a/src/Promitor.Agents.Scraper/Startup.cs
+++ b/src/Promitor.Agents.Scraper/Startup.cs
@@ -6,6 +6,7 @@
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 using Promitor.Agents.Core;
 using Promitor.Agents.Scraper.Configuration;
 using Promitor.Agents.Scraper.Configuration.Sinks;
@@ -54,7 +55,7 @@ public void ConfigureServices(IServiceCollection services)
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
-        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILogger<Startup> logger)
         {
             if (env.IsDevelopment())
             {
@@ -66,7 +67,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 .UseHttpCorrelation()
                 .UseVersionMiddleware()
                 .UseRouting()
-                .UseMetricSinks(Configuration)
+                .UseMetricSinks(Configuration, logger)
                 .ExposeOpenApiUi(ApiName)
                 .UseEndpoints(endpoints => endpoints.MapControllers());
 
@@ -99,7 +100,7 @@ private string BuildOpenApiDescription(IConfiguration configuration)
                 if (metricSinkConfiguration.PrometheusScrapingEndpoint != null)
                 {
                     var prometheusScrapingBaseUri = metricSinkConfiguration.PrometheusScrapingEndpoint.BaseUriPath;
-                    openApiDescriptionBuilder.AppendLine($"<li>Prometheus scrape endpoint is exposed at <a href=\"./../..{prometheusScrapingBaseUri}\" target=\"_blank\">{prometheusScrapingBaseUri}</a></li>");
+                    openApiDescriptionBuilder.AppendLine($"<li>Prometheus scrape endpoint is exposed at <a href=\"../{prometheusScrapingBaseUri}\" target=\"_blank\">{prometheusScrapingBaseUri}</a></li>");
                 }
 
                 if (metricSinkConfiguration.Statsd != null)