Christoph
I have a similar question. Note that the discussion below applies to using code clients, not Postman.
As matters stand now, it does not seem to be possible to determine whether a given service ticket is valid. There are, then, two logical options:
- Hope that the service ticket remains valid for as long as is necessary to execute multiple requests in a session
- Obtain a new ticket before every request
The first option is indeterministic, as one can't know how long the processing will take for the requests in a given session. It is perfectly possible that one can write code that works in a test environment with limited data loads, but which fails in production with higher and changing data loads.
So, hoping that the ticket remains valid for as long as it takes is to risk creating a situation that leads to random and hard to replicate errors.
The second option means that you need to make twice as many requests, as each functional request has to be preceded with an authentication request. This increases the load on the server, increases latency for a given logical functional request, and increases the potential for partial failure.
Consequently, the only proper solution here is to check each functional request for exceptions, which one would properly do anyway, and check for session timeout failures as part of the exception/response code handling. In the case of an exception for a session timeout, the code would need to reauthenticate, create a new token, and then re-execute the functional request. This is cumbersome, but unavoidable.
A pseudo-code version is below:
while True:
try:
headers = {'x-auth-token': token, 'content-type': "application/json"}
result = requests.put(url=url, data=json.dumps(payload), headers=headers, verify=verify)
result.raise_for_status()
if result.status_code != 202:
print("Response code is not 202, so no task was created.")
else:
taskId = result.json()['response']['taskId']
task_status = check_task(taskId)
print("Task status is: \n" + json.dumps(task_status, indent=2))
break
except requests.exceptions.HTTPError as e:
print("Exception when making request - " + str(e))
if e.response.status_code == 401:
print("401 exception with request, refreshing token.")
token = get_token()
It would be slightly better if the API did allow for session revalidation, as with the APIC-DC API, so perhaps the APIC-EM API designers might consider that.
Regards
Nathan
