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Jasono
11/24/2020, 6:00 PMHi does the Context {…} defined in the Prefect Cloud web UI (I’m referring to the Run screen where Parameters and Context are manually entered) override the same context variables in config.toml? It appears to me the context entered in the web UI is ignored.
j
josh
11/24/2020, 6:52 PMHi @Jasono certain values present in context at run time will be overwritten after the user provided context is loaded (i.e. flow id, flow run id, scheduled start time) because these values are used for the runner during execution of the flow.
Relevant code where context is loaded: https://github.com/PrefectHQ/prefect/blob/master/src/prefect/engine/cloud/flow_runner.py#L372-L380
j
Jasono
11/24/2020, 6:55 PMSorry I wasn’t clear. These are user defined variables that are overriden, not those you mentioned.
j
josh
11/24/2020, 6:57 PMNot sure if I follow, if I set context variables in the web UI I see them being populated in the flow run. 🤔 What are you attempting?
j
Jasono
11/24/2020, 6:58 PMI want to pass “reporting period” for instance
don’t want to use Parameter for that.
Do you also define those user defined context variables in your config.toml?
I do, because otherwise the flow script fails when I try to register it
j
josh
11/24/2020, 7:02 PMHow are you accessing the variable from context? Registration does not run the flow. If you’re doing something like this:
Copy code
with Flow():
my_task(context.get("reports")) Copy code
@task
def my_task():
prefect.context("reports")j
Jasono
11/24/2020, 7:06 PMI’m trying to do it like your first example, and it is necessary as I dynamically create tasks within the Flow block.
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with Flow("bdx_process_9xx") as flow:
acctDate = str(prefect.context.acctDate)
prodDate = str(prefect.context.prodDate)
runDesc9xx = prefect.context.runDesc9xx
print(f'ProdDate={prodDate} ..{runDesc9xx}')
for queryKey, (queryCmd, dependQry) in cmdPairs(acctDate, prodDate, runDesc9xx).items():
task = BDX_Task(name=queryKey)(queryKey =queryKey,
queryCmd=queryCmd
)
flow.add_task(task)
if len(dependQry) > 0 :
if type(dependQry) is list:
for q in dependQry:
flow.get_tasks(name=queryKey)[0].set_upstream(flow.get_tasks(name=q)[0])
else:
flow.get_tasks(name=queryKey)[0].set_upstream(flow.get_tasks(name=dependQry)[0])j
josh
11/24/2020, 7:15 PMYeah in your snippet you are grabbing values from your local context and passing them into the tasks you create therefore they are static and cannot be changed. If you want to access a dynamic context value at runtime instead of build time then you will need to grab it from context in a similar way to the snippet I provided above.
j
Jasono
11/24/2020, 7:16 PMokay. thank you!
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