Added a new task to handle any error cases with the anti-virus

application. If the Anti-virus app fails due to s3 errors or ClamAV
so does not scan (even after retries) the file at all an error needs
to be raised and the notification set to technical-failure.

Files should be moved to a 'folder' a separate one for ERROR and FAILURE.

* Added new letter task to process the error
* Added a new method to letter utils.py to move a file into an error or
failure folder based on the input
* Added tests to test the task and the utils.py method

tests/app/celery/test_letters_pdf_tasks.py

@@ -19,8 +19,8 @@ from app.celery.letters_pdf_tasks import (
     letter_in_created_state,
     process_virus_scan_passed,
     process_virus_scan_failed,
-)
-from app.letters.utils import get_letter_pdf_filename
+    process_virus_scan_error)
+from app.letters.utils import get_letter_pdf_filename, ScanErrorType
 from app.models import (
     KEY_TYPE_NORMAL,
     KEY_TYPE_TEST,
@@ -28,8 +28,8 @@ from app.models import (
     NOTIFICATION_CREATED,
     NOTIFICATION_DELIVERED,
     NOTIFICATION_VIRUS_SCAN_FAILED,
-    NOTIFICATION_SENDING
-)
+    NOTIFICATION_SENDING,
+    NOTIFICATION_TECHNICAL_FAILURE)
 
 from tests.conftest import set_config_values
 
@@ -341,9 +341,20 @@ def test_process_letter_task_check_virus_scan_passed(
 def test_process_letter_task_check_virus_scan_failed(sample_letter_notification, mocker):
     filename = 'NOTIFY.{}'.format(sample_letter_notification.reference)
     sample_letter_notification.status = 'pending-virus-check'
-    mock_delete_pdf = mocker.patch('app.celery.letters_pdf_tasks.delete_pdf_from_letters_scan_bucket')
+    mock_move_failed_pdf = mocker.patch('app.celery.letters_pdf_tasks.move_failed_pdf')
 
     process_virus_scan_failed(filename)
 
-    mock_delete_pdf.assert_called_once_with(filename)
+    mock_move_failed_pdf.assert_called_once_with(filename, ScanErrorType.FAILURE)
     assert sample_letter_notification.status == NOTIFICATION_VIRUS_SCAN_FAILED
+
+
+def test_process_letter_task_check_virus_scan_error(sample_letter_notification, mocker):
+    filename = 'NOTIFY.{}'.format(sample_letter_notification.reference)
+    sample_letter_notification.status = 'pending-virus-check'
+    mock_move_failed_pdf = mocker.patch('app.celery.letters_pdf_tasks.move_failed_pdf')
+
+    process_virus_scan_error(filename)
+
+    mock_move_failed_pdf.assert_called_once_with(filename, ScanErrorType.ERROR)
+    assert sample_letter_notification.status == NOTIFICATION_TECHNICAL_FAILURE

tests/app/letters/test_letter_utils.py

@@ -11,8 +11,8 @@ from app.letters.utils import (
     get_letter_pdf_filename,
     get_letter_pdf,
     upload_letter_pdf,
-    move_scanned_pdf_to_test_or_live_pdf_bucket
-)
+    move_scanned_pdf_to_test_or_live_pdf_bucket,
+    ScanErrorType, move_failed_pdf)
 from app.models import KEY_TYPE_NORMAL, KEY_TYPE_TEST, PRECOMPILED_TEMPLATE_NAME
 from app.variables import Retention
 
@@ -163,3 +163,43 @@ def test_move_scanned_letter_pdf_to_processing_bucket(
 
     assert folder_date_name + filename in [o.key for o in target_bucket.objects.all()]
     assert filename not in [o.key for o in source_bucket.objects.all()]
+
+
+@mock_s3
+@freeze_time(FROZEN_DATE_TIME)
+def test_move_failed_pdf_error(notify_api):
+    filename = 'test.pdf'
+    source_bucket_name = current_app.config['LETTERS_SCAN_BUCKET_NAME']
+    target_bucket_name = current_app.config['LETTERS_SCAN_BUCKET_NAME']
+
+    conn = boto3.resource('s3', region_name='eu-west-1')
+    source_bucket = conn.create_bucket(Bucket=source_bucket_name)
+    target_bucket = conn.create_bucket(Bucket=target_bucket_name)
+
+    s3 = boto3.client('s3', region_name='eu-west-1')
+    s3.put_object(Bucket=source_bucket_name, Key=filename, Body=b'pdf_content')
+
+    move_failed_pdf(filename, ScanErrorType.ERROR)
+
+    assert 'ERROR/' + filename in [o.key for o in target_bucket.objects.all()]
+    assert filename not in [o.key for o in source_bucket.objects.all()]
+
+
+@mock_s3
+@freeze_time(FROZEN_DATE_TIME)
+def test_move_failed_pdf_scan_failed(notify_api):
+    filename = 'test.pdf'
+    source_bucket_name = current_app.config['LETTERS_SCAN_BUCKET_NAME']
+    target_bucket_name = current_app.config['LETTERS_SCAN_BUCKET_NAME']
+
+    conn = boto3.resource('s3', region_name='eu-west-1')
+    source_bucket = conn.create_bucket(Bucket=source_bucket_name)
+    target_bucket = conn.create_bucket(Bucket=target_bucket_name)
+
+    s3 = boto3.client('s3', region_name='eu-west-1')
+    s3.put_object(Bucket=source_bucket_name, Key=filename, Body=b'pdf_content')
+
+    move_failed_pdf(filename, ScanErrorType.FAILURE)
+
+    assert 'FAILURE/' + filename in [o.key for o in target_bucket.objects.all()]
+    assert filename not in [o.key for o in source_bucket.objects.all()]