Use values provided by users for WindowDuration and NumShards

[barata]

Previous version ignores users parameters and always takes the defaults (1 shard and 5m window duration).

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed (or fixed any issues), please reply here (e.g. I signed it!) and we'll verify it.

---

What to do if you already signed the CLA

Individual signers

• It's possible we don't have your GitHub username or you're using a different email address on your commit. Check your existing CLA data and verify that your email is set on your git commits.

Corporate signers

• Your company has a Point of Contact who decides which employees are authorized to participate. Ask your POC to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the Google project maintainer to go/cla#troubleshoot (Public version).
• The email used to register you as an authorized contributor must be the email used for the Git commit. Check your existing CLA data and verify that your email is set on your git commits.
• The email used to register you as an authorized contributor must also be attached to your GitHub account.

ℹ️ Googlers: Go here for more info.

[barata]

I signed it!

[googlebot]

CLAs look good, thanks!

ℹ️ Googlers: Go here for more info.

[sabhyankar]

Hi Barata - Thank you for the PR! A lot of the methods used in the Beam IO transforms do no support ValueProvider as an input and the current release of Dataflow templates requires any runtime parameters to be wrapped inside of ValueProviders. I think the better approach to doing this would be to use a new feature called Dynamic Templates that we are looking to roll out soon.

For e.g.:
AvroIO.Write.withNumShards

[sabhyankar]

This will not work unfortunately as AvroIO.Write.withNumShards(int) does not support a ValueProvider as an input. The same goes for some of the other parameters below.

[barata]

I see it now. I was trying to fix an existing bug when you create DF jobs using GCP Console "Export from Pubsub to GCS" feature. I have an on-going internal ticket with Google that I will follow up on. Thanks for your comments anyway.

[dtcrout]

Is there any status update on this issue? I'm encountering a similar issue with windowDuration for PubsubToText template. The default value of windowDuration is taken and the parameter value is ignored.