Handle connection errors

ia-upload-stream

@@ -113,14 +113,19 @@ def upload(item, filename, metadata, *, iaConfigFile = None, partSize = 4, tries
 		for attempt in range(1, tries + 1):
 			if attempt > 1:
 				logger.info(f'Retrying part {partNumber}')
-			r = requests.put(f'{url}?partNumber={partNumber}&uploadId={uploadId}', headers = {**headers, 'Content-MD5': contentMd5}, data = data)
-			if r.status_code == 200:
-				break
+			try:
+				r = requests.put(f'{url}?partNumber={partNumber}&uploadId={uploadId}', headers = {**headers, 'Content-MD5': contentMd5}, data = data)
+			except (ConnectionError, requests.exceptions.RequestException) as e:
+				err = f'error {type(e).__module__}.{type(e).__name__} {e!s}'
+			else:
+				if r.status_code == 200:
+					break
+				err = f'status {r.status_code}'
 			sleepTime = min(3 ** attempt, 30)
 			retrying = f', retrying after {sleepTime} seconds' if attempt < tries else ''
-			logger.error(f'Got status {r.status_code} from IA S3 on uploading part {partNumber}{retrying}')
+			logger.error(f'Got {err} from IA S3 on uploading part {partNumber}{retrying}')
 			if attempt == tries:
-				raise UploadError(f'Got status {r.status_code} from IA S3 on uploading part {partNumber}', r = r, uploadId = uploadId, parts = parts)
+				raise UploadError(f'Got {err} from IA S3 on uploading part {partNumber}', r = r, uploadId = uploadId, parts = parts)
 			time.sleep(sleepTime)
 		logger.info(f'Upload OK, ETag: {r.headers["ETag"]}')
 		parts.append((partNumber, r.headers['ETag']))