Poll

The Poll task is most commonly used in combination with the REST task to Poll for a job completion status, however, it can be used to Poll any HTTP server and wait for a success or failure criteria to be evaluated - or a timeout to expire.

Poll Request

• URL - this is the URL that the Poll task should poll
• Count - how many times should the Poll task attempt to access the URL
• Interval (in seconds) - how long should the Poll task pause between attempts to access
• Ignore Intermediate Failure - ignore intermediate failures, useful if you’re waiting for a service to become available before you can poll it
• Headers - which headers should be sent with the request (e.g. Accept: application/json, Content-Type: application/json, Authorization: Bearer 4DFJGR...)

Exit Criteria

• Success Condition - if this evaluates to true then the task will return a success, and the pipeline will continue.
• Failure Condition - if this evaluates to true then the task will return a failure, and the pipeline will halt (unless Continue on failure is checked)

For example, the below Poll task is configured to query the status of an Image Enumeration task in Cloud Assembly, and wait for either a status of FINISHED or FAILED.

The JSON values returned in the body of the response will are available as properties to test, so in the JSON response below the property status can be evaluated for both the success and failure condition, with the value determining which condition is triggered.

{
    "progress":100,
    "status":"FINISHED",
    "name":"Private image enumeration",
    "id":"fb719d5a-f30d-4467-9622-31b765b9d369",
    "selfLink":"/iaas/api/request-tracker/fb719d5a-f30d-4467-9622-31b765b9d369"
}

Task Outputs

• status
• iterationCount
• pollCount
• expectedResponse
• responseHeaders
• responseBody
• interval
• processedUrl
• responseJson
• inputHeaders
• responseCode