func getDownloaders()

in main/files.go [52:92]
32 lines of code
12 McCabe index (conditional complexity)

func getDownloaders(fileURL string, storageAccountName, storageAccountKey string, managedIdentity *clientOrObjectId) (
	[]download.Downloader, error) {
	if storageAccountName == "" || storageAccountKey == "" {
		// storage account name and key cannot be specified with managed identity, handler settings validation won't allow that
		// handler settings validation will also not allow storageAccountName XOR storageAccountKey == 1
		// in this case, we can be sure that storage account name and key was not specified
		if download.IsAzureStorageBlobUri(fileURL) && managedIdentity != nil {
			// if managed identity was specified in the configuration, try to use it to download the files
			var msiProvider download.MsiProvider
			switch {
			case managedIdentity.ClientId == "" && managedIdentity.ObjectId == "":
				// get msi using clientId or objectId or implicitly
				msiProvider = download.GetMsiProviderForStorageAccountsImplicitly(fileURL)
			case managedIdentity.ClientId != "" && managedIdentity.ObjectId == "":
				msiProvider = download.GetMsiProviderForStorageAccountsWithClientId(fileURL, managedIdentity.ClientId)
			case managedIdentity.ClientId == "" && managedIdentity.ObjectId != "":
				msiProvider = download.GetMsiProviderForStorageAccountsWithObjectId(fileURL, managedIdentity.ObjectId)
			default:
				return nil, fmt.Errorf("unexpected combination of ClientId and ObjectId found")
			}
			return []download.Downloader{
				// try downloading without MSI token first, but attempt with MSI if the download fails
				download.NewURLDownload(fileURL),
				download.NewBlobWithMsiDownload(fileURL, msiProvider),
			}, nil
		} else {
			// do not use MSI downloader if the uri is not azure storage blob, or managedIdentity isn't specified
			return []download.Downloader{download.NewURLDownload(fileURL)}, nil
		}
	} else {
		// if storage name account and key are specified, use that for all files
		// this preserves old behavior
		blob, err := blobutil.ParseBlobURL(fileURL)
		if err != nil {
			return nil, err
		}
		return []download.Downloader{download.NewBlobDownload(
			storageAccountName, storageAccountKey,
			blob)}, nil
	}
}