C#: Add more logging to DependabotProxy

Author: mbg

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DependabotProxy.cs

@@ -22,34 +22,40 @@ internal class DependabotProxy
         /// </summary>
         internal bool IsConfigured => !string.IsNullOrEmpty(this.Address);
 
-        internal DependabotProxy(TemporaryDirectory tempWorkingDirectory)
+        internal DependabotProxy(ILogger logger, TemporaryDirectory tempWorkingDirectory)
         {
             // Obtain and store the address of the Dependabot proxy, if available.
             this.host = Environment.GetEnvironmentVariable(EnvironmentVariableNames.ProxyHost);
             this.port = Environment.GetEnvironmentVariable(EnvironmentVariableNames.ProxyPort);
 
             if (string.IsNullOrWhiteSpace(host) || string.IsNullOrWhiteSpace(port))
             {
+                logger.LogInfo("No Dependabot proxy credentials are configured.");
                 return;
             }
 
             this.Address = $"http://{this.host}:{this.port}";
+            logger.LogInfo($"Dependabot proxy configured at {this.Address}");
 
             // Obtain and store the proxy's certificate, if available.
             var cert = Environment.GetEnvironmentVariable(EnvironmentVariableNames.ProxyCertificate);
 
             if (string.IsNullOrWhiteSpace(cert))
             {
+                logger.LogInfo("No certificate configured for Dependabot proxy.");
                 return;
             }
 
             var certDirPath = new DirectoryInfo(Path.Join(tempWorkingDirectory.DirInfo.FullName, ".dependabot-proxy"));
             Directory.CreateDirectory(certDirPath.FullName);
 
-            this.certFile = new FileInfo(Path.Join(certDirPath.FullName, "proxy.crt"));
+            var certFilePath = Path.Join(certDirPath.FullName, "proxy.crt");
+            this.certFile = new FileInfo(certFilePath);
 
             using var writer = this.certFile.CreateText();
             writer.Write(cert);
+
+            logger.LogInfo($"Stored Dependabot proxy certificate at {certFilePath}");
         }
 
         internal void ApplyProxy(ILogger logger, ProcessStartInfo startInfo)

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotNetCliInvoker.cs

@@ -19,7 +19,7 @@ internal sealed class DotNetCliInvoker : IDotNetCliInvoker
         public DotNetCliInvoker(ILogger logger, string exec, TemporaryDirectory tempWorkingDirectory)
         {
             this.logger = logger;
-            this.proxy = new DependabotProxy(tempWorkingDirectory);
+            this.proxy = new DependabotProxy(logger, tempWorkingDirectory);
             this.Exec = exec;
             logger.LogInfo($"Using .NET CLI executable: '{Exec}'");
         }