protected override async Task ApplyContextAsync()

in src/WebJobs.Script.WebHost/Management/AtlasInstanceManager.cs [244:335]
81 lines of code
15 McCabe index (conditional complexity)

        protected override async Task ApplyContextAsync(HostAssignmentContext assignmentContext)
        {
            // We need to get the non-PlaceholderMode script Path so we can unzip to the correct location.
            // This asks the factory to skip the PlaceholderMode check when configuring options.
            var options = _optionsFactory.Create(ScriptApplicationHostOptionsSetup.SkipPlaceholder);
            RunFromPackageContext pkgContext = assignmentContext.GetRunFromPkgContext();

            if (_environment.SupportsAzureFileShareMount() || pkgContext.IsRunFromLocalPackage())
            {
                var azureFilesMounted = false;
                if (assignmentContext.IsAzureFilesContentShareConfigured(_logger))
                {
                    azureFilesMounted = await _runFromPackageHandler.MountAzureFileShare(assignmentContext);
                }
                else
                {
                    _logger.LogError(
                        $"No {nameof(EnvironmentSettingNames.AzureFilesConnectionString)} or {nameof(EnvironmentSettingNames.AzureFilesContentShare)} configured. Azure FileShare will not be mounted. For PowerShell Functions, Managed Dependencies will not persisted across functions host instances.");
                }

                if (pkgContext.IsRunFromPackage(options, _logger))
                {
                    if (azureFilesMounted)
                    {
                        _logger.LogWarning("App is configured to use both Run-From-Package and AzureFiles. Run-From-Package will take precedence");
                    }
                    var blobContextApplied =
                        await _runFromPackageHandler.ApplyRunFromPackageContext(pkgContext, options.ScriptPath,
                            azureFilesMounted, false);

                    if (!blobContextApplied && azureFilesMounted)
                    {
                        _logger.LogWarning($"Failed to {nameof(_runFromPackageHandler.ApplyRunFromPackageContext)}. Attempting to use local disk instead");
                        await _runFromPackageHandler.ApplyRunFromPackageContext(pkgContext, options.ScriptPath, false);
                    }
                }
                else if (pkgContext.IsRunFromLocalPackage())
                {
                    if (!azureFilesMounted)
                    {
                        const string mountErrorMessage = "App Run-From-Package is set as '1'. AzureFiles is needed but is not configured.";
                        _logger.LogWarning(mountErrorMessage);
                        throw new Exception(mountErrorMessage);
                    }

                    var blobContextApplied =
                        await _runFromPackageHandler.ApplyRunFromPackageContext(pkgContext, options.ScriptPath, azureFilesMounted);

                    if (!blobContextApplied)
                    {
                        _logger.LogWarning($"Failed to {nameof(_runFromPackageHandler.ApplyRunFromPackageContext)}.");
                    }
                }
                else
                {
                    _logger.LogInformation($"No {nameof(EnvironmentSettingNames.AzureWebsiteRunFromPackage)} configured");
                }
            }
            else
            {
                if (pkgContext.IsRunFromPackage(options, _logger))
                {
                    await _runFromPackageHandler.ApplyRunFromPackageContext(pkgContext, options.ScriptPath, false);
                }
                else if (assignmentContext.IsAzureFilesContentShareConfigured(_logger))
                {
                    await _runFromPackageHandler.MountAzureFileShare(assignmentContext);
                }
            }

            // BYOS
            var storageVolumes = assignmentContext.GetBYOSEnvironmentVariables()
                .Select(AzureStorageInfoValue.FromEnvironmentVariable).ToList();

            var mountedVolumes =
                (await Task.WhenAll(storageVolumes.Where(v => v != null).Select(MountStorageAccount))).Where(
                    result => result).ToList();

            if (storageVolumes.Any())
            {
                if (mountedVolumes.Count != storageVolumes.Count)
                {
                    _logger.LogWarning(
                        $"Successfully mounted {mountedVolumes.Count} / {storageVolumes.Count} BYOS storage accounts");
                }
                else
                {
                    _logger.LogInformation(
                        $"Successfully mounted {storageVolumes.Count} BYOS storage accounts");
                }
            }
        }