DataSourceOpenstack: Retry when waiting for the metadata service too

This bug was originally filed in Launchpad as [LP: #1979049](https://bugs.launchpad.net/cloud-init/+bug/1979049)

Launchpad details

affected_projects = []

assignee = None

assignee_name = None

date_closed = 2022-06-20T18:46:41.398407+00:00

date_created = 2022-06-17T09:59:38.781185+00:00

date_fix_committed = None

date_fix_released = None

id = 1979049

importance = wishlist

is_complete = True

lp_url = https://bugs.launchpad.net/cloud-init/+bug/1979049

milestone = None

owner = dcaro

owner_name = David Caro

private = False

status = opinion

submitter = dcaro

submitter_name = David Caro

tags = []

duplicates = []

_Launchpad user **David Caro(dcaro)** wrote on 2022-06-17T09:59:38.781185+00:00_

We are having some instability in our Openstack Wallaby systems right now, and have found that even though passing the "retries" option cloud-init openstack datasource, the code might fail also on a first attempt to detect alive metadata services as it's not retrying at that point (only when trying to fetch the data itself).

Some logs of the error:
```
2022-06-16 03:25:35,449 - url_helper.py[DEBUG]: [0/1] open 'http://169.254.169.254/openstack' with {'url': 'http://169.254.169.254/openstack', 'allow_redirects': True, 'method': 'GET', 'timeou
t': 10.0, 'headers': {'User-Agent': 'Cloud-Init/20.4.1'}} configuration
2022-06-16 03:25:45,469 - url_helper.py[DEBUG]: Calling 'http://169.254.169.254/openstack' failed [10/-1s]: request error [HTTPConnectionPool(host='169.254.169.254', port=80): Read timed out.
(read timeout=10.0)]
2022-06-16 03:25:45,471 - DataSourceOpenStack.py[DEBUG]: Giving up on OpenStack md from ['http://169.254.169.254/openstack'] after 10 seconds
2022-06-16 03:25:45,471 - util.py[WARNING]: No active metadata service found
2022-06-16 03:25:45,477 - util.py[DEBUG]: No active metadata service found
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/cloudinit/sources/DataSourceOpenStack.py", line 145, in _get_data
results = self._crawl_metadata()
File "/usr/lib/python3/dist-packages/cloudinit/sources/DataSourceOpenStack.py", line 181, in _crawl_metadata
raise sources.InvalidMetaDataException(
cloudinit.sources.InvalidMetaDataException: No active metadata service found
```

We think that it should retry to fetch also on this first pass (we are looking also on the instability sources, but this would help make it more resilient).

The issue points to cloudinit/sources/DataSourceOpenStack.py and the _get_data/_crawl_metadata traceback. Read those entry points first, then trace how the OpenStack datasource applies the retries option during metadata-service detection. Done means an initial metadata-service timeout is retried rather than immediately raising InvalidMetaDataException.

Written by the indexing model from the issue text.