patroni.scripts.barman.utils module

Utilitary stuff to be used by Barman related scripts.

exception patroni.scripts.barman.utils.ApiNotOk

Bases: Exception

The pg-backup-api is not currently up and running.

class patroni.scripts.barman.utils.OperationStatus

Bases: enum.IntEnum

Possible status of pg-backup-api operations.

Variables:
  • IN_PROGRESS – the operation is still ongoing.
  • FAILED – the operation failed.
  • DONE – the operation finished successfully.
DONE = 2
FAILED = 1
IN_PROGRESS = 0
class patroni.scripts.barman.utils.PgBackupApi(api_url: str, cert_file: Optional[str], key_file: Optional[str], retry_wait: int, max_retries: int)

Bases: object

Facilities for communicating with the pg-backup-api.

Variables:
  • api_url – base URL to reach the pg-backup-api.
  • cert_file – certificate to authenticate against the pg-backup-api, if required.
  • key_file – certificate key to authenticate against the pg-backup-api, if required.
  • retry_wait – how long in seconds to wait before retrying a failed request to the pg-backup-api.
  • max_retries – maximum number of retries when pg-backup-api returns malformed responses.
  • http – a HTTP pool manager for performing web requests.
__init__(api_url: str, cert_file: Optional[str], key_file: Optional[str], retry_wait: int, max_retries: int) → None

Create a new instance of BarmanRecover.

Make sure the pg-backup-api is reachable and running fine.

Note

When using any method which send requests to the API, be aware that they might raise RetriesExceeded upon HTTP request errors.

Similarly, when instantiating this class you may face an ApiNotOk, if the API is down or returns a bogus status.

Parameters:
  • api_url – base URL to reach the pg-backup-api.
  • cert_file – certificate to authenticate against the pg-backup-api, if required.
  • key_file – certificate key to authenticate against the pg-backup-api, if required.
  • retry_wait – how long in seconds to wait before retrying a failed request to the pg-backup-api.
  • max_retries – maximum number of retries when pg-backup-api returns malformed responses.
_build_full_url(url_path: str) → str

Build the full URL by concatenating url_path with the base URL.

Parameters:url_path – path to be accessed in the pg-backup-api.
Returns:the full URL after concatenating.
static _deserialize_response(response: urllib3.response.HTTPResponse) → Any

Retrieve body from response as a deserialized JSON object.

Parameters:response – response from which JSON body will be deserialized.
Returns:the deserialized JSON body.
_ensure_api_ok() → None

Ensure pg-backup-api is reachable and OK.

Raises:ApiNotOk: if pg-backup-api status is not OK.
_get_request(url_path: str) → Any

Perform a GET request to url_path.

Parameters:

url_path – URL to perform the GET request against.
Returns:

the deserialized response body.
Raises:
RetriesExceeded: raised from the corresponding urllib3

exception.
_post_request(url_path: str, body: Any) → Any

Perform a POST request to url_path serializing body as JSON.

Parameters:
  • url_path – URL to perform the POST request against.
  • body – the body to be serialized as JSON and sent in the request.
Returns:

the deserialized response body.
Raises:
RetriesExceeded: raised from the corresponding urllib3

exception.
static _serialize_request(body: Any) → Any

Serialize a request body.

Parameters:body – content of the request body to be serialized.
Returns:the serialized request body.
create_config_switch_operation(*args, **kwargs) → Any
create_recovery_operation(*args, **kwargs) → Any
get_operation_status(*args, **kwargs) → Any
exception patroni.scripts.barman.utils.RetriesExceeded

Bases: Exception

Maximum number of retries exceeded.

patroni.scripts.barman.utils.retry(exceptions: Union[Type[Exception], Tuple[Type[Exception], ...]]) → Any

Retry an operation n times if expected exceptions are faced.

Note

Should be used as a decorator of a class’ method as it expects the first argument to be a class instance.

The class which method is going to be decorated should contain a couple attributes:

  • max_retries: maximum retry attempts before failing;
  • retry_wait: how long in seconds to wait before retrying.
Parameters:

exceptions – exceptions that could trigger a retry attempt.
Raises:
RetriesExceeded: if the maximum number of attempts has been

exhausted.
patroni.scripts.barman.utils.set_up_logging(log_file: Optional[str] = None) → None

Set up logging to file, if log_file is given, otherwise to console.

Parameters:log_file – file where to log messages, if any.