Allow package to exist in packages container when becoming to Available (#356)

Fix NuGet/NuGetGallery#5577

Author: joelverhagen

src/NuGet.Services.Validation.Orchestrator/ValidationOutcomeProcessor.cs

@@ -177,7 +177,23 @@ private async Task MoveFileToPublicStorageAndMarkPackageAsAvailable(PackageValid
                 package.NormalizedVersion,
                 validationSet.ValidationTrackingId);
             var packageStream = await _packageFileService.DownloadValidationPackageFileAsync(package);
-            await _packageFileService.SavePackageFileAsync(package, packageStream);
+
+            try
+            {
+                await _packageFileService.SavePackageFileAsync(package, packageStream);
+            }
+            catch (InvalidOperationException)
+            {
+                // The package already exists in the packages container. This can happen if the DB commit below fails
+                // and this flow is retried. We assume that the package content has not changed. Today there is no way
+                // for the content to change. Hard deletes (the one way a package ID and version can get different
+                // content) delete from both the packages and validating container so this can't be a mismatch.
+                _logger.LogInformation(
+                    "Package already exists in packages container for {PackageId} {PackageVersion}, validation set {ValidationSetId}",
+                    package.PackageRegistration.Id,
+                    package.NormalizedVersion,
+                    validationSet.ValidationTrackingId);
+            }
 
             _logger.LogInformation("Marking package {PackageId} {PackageVersion}, validation set {ValidationSetId} as {PackageStatus} in DB",
                 package.PackageRegistration.Id,

tests/NuGet.Services.Validation.Orchestrator.Tests/ValidationOutcomeProcessorFacts.cs

@@ -153,6 +153,37 @@ public async Task CopiesPackageToPublicStorageAndSendsEmailUponSuccess()
                 .Verify(ms => ms.SendPackagePublishedMessage(It.IsAny<Package>()), Times.Once());
         }
 
+        [Fact]
+        public async Task AllowsPackageAlreadyInPublicContainer()
+        {
+            AddValidation("validation1", ValidationStatus.Succeeded);
+            Package.PackageStatusKey = PackageStatus.Validating;
+
+            var stream = new MemoryStream();
+
+            PackageFileServiceMock
+                .Setup(pfs => pfs.DownloadValidationPackageFileAsync(Package))
+                .ReturnsAsync(stream);
+
+            PackageFileServiceMock
+                .Setup(pfs => pfs.SavePackageFileAsync(It.IsAny<Package>(), It.IsAny<Stream>()))
+                .Throws(new InvalidOperationException("Duplicate!"));
+
+            var processor = CreateProcessor();
+            await processor.ProcessValidationOutcomeAsync(ValidationSet, Package);
+
+            PackageFileServiceMock
+                .Verify(pfs => pfs.DownloadValidationPackageFileAsync(Package), Times.Once);
+            PackageFileServiceMock
+                .Verify(pfs => pfs.SavePackageFileAsync(Package, stream), Times.Once);
+            PackageServiceMock
+                .Verify(ps => ps.UpdatePackageStatusAsync(Package, PackageStatus.Available, true), Times.Once);
+            PackageFileServiceMock
+                .Verify(pfs => pfs.DeleteValidationPackageFileAsync(Package.PackageRegistration.Id, Package.Version), Times.Once);
+            MessageServiceMock
+                .Verify(ms => ms.SendPackagePublishedMessage(Package), Times.Once);
+        }
+
         [Fact]
         public async Task DoesNotCopyPackageIfItsAvailable()
         {