Fix: Added policy to retry Update call

src/GraphDeployer/Deployer.cs

@@ -6,6 +6,7 @@ using Coscine.GraphDeployer.Utils;
 using LibGit2Sharp;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
+using Polly;
 using VDS.RDF;
 using static Coscine.GraphDeployer.Utils.CommandLineOptions;
 using Configuration = Coscine.ApiClient.Core.Client.Configuration;
@@ -129,11 +130,15 @@ public class Deployer(ILogger<Deployer> logger, IOptionsMonitor<GraphDeployerCon
                         var rdfWriter = MimeTypesHelper.GetWriter(format);
                         var content = VDS.RDF.Writing.StringWriter.Write(graph, rdfWriter);
                         if (!opts.DummyMode)
+                        {
+                            // Retry the operation in case of failure up to 3 times using exponential backoff (2^retryAttempt seconds as the delay between retries)
+                            await Policy.Handle<Exception>().WaitAndRetry(3, (retryAttempt) => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt))).Execute(async () =>
                             {
                                 await _adminApi.UpdateMetadataGraphAsync(
                                     graph.BaseUri.AbsoluteUri,
                                     new MetadataUpdateAdminParameters(new RdfDefinitionForManipulationDto(content, formatEnum))
                                 );
+                            });
                         }
 
                         _logger.LogInformation("Deployed {graphName} successfully.", graphId);

src/GraphDeployer/GraphDeployer.csproj

@@ -29,6 +29,7 @@
 		<PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="8.0.0" />
 		<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
 		<PackageReference Include="Microsoft.Extensions.Http" Version="8.0.0" />
+		<PackageReference Include="Microsoft.Extensions.Http.Resilience" Version="8.4.0" />
 		<PackageReference Include="Microsoft.Extensions.Options" Version="8.0.2" />
 		<PackageReference Include="NLog" Version="5.2.8" />
 		<PackageReference Include="NLog.Extensions.Logging" Version="5.3.8" />