Allow to create subscriptions independently with topic

[onimsha]

Fixes #71

[comment-bot-dev]

Thanks for the PR! 🚀
✅ Lint checks have passed.

[google-cla]

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 with @googlebot 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.

[onimsha]

@googlebot I signed it!

[morgante]

Thanks for the PR. I'm not sure we want to change this so that each subscription can have a different topic though, as I think that's very different from the original intent of the module.

If you do want to have this, all of the subscriptions should be attached to the same topic.

[onimsha]

Thanks for the PR. I'm not sure we want to change this so that each subscription can have a different topic though, as I think that's very different from the original intent of the module.

If you do want to have this, all of the subscriptions should be attached to the same topic.

Got it. Then how about this ?

• Introduce a new variable, existing_topic, to use in the case create_topic = false .
• Let all the subscriptions use the same topic, declared in existing_topic
• Add another example to use the existing_topic by creating the topic in a project, while subscriptions in another project.

If you think we can go with this approach, i will make the changes.

[morgante]

@onimsha I'm not sure I follow your use case.

If you want to attach subscriptions without creating the topic, why wouldn't you just set create_topic = false?

[onimsha]

@onimsha I'm not sure I follow your use case.

If you want to attach subscriptions without creating the topic, why wouldn't you just set create_topic = false?

Because many resources in this module depend on this for_each = var.create_topic . One it's set to be false none of them will be created

[morgante]

Because many resources in this module depend on this for_each = var.create_topic . One it's set to be false none of them will be created

I think we should update those resources to check a separate create_subscriptions variable instead. So, the new flow would be:

1. If create_topic and create_subscriptions are both true (default) it creates both.
2. If only create_subscriptions is true, only create subscriptions.
3. If only create_topic is true, only create topic.

[onimsha]

Because many resources in this module depend on this for_each = var.create_topic . One it's set to be false none of them will be created

I think we should update those resources to check a separate create_subscriptions variable instead. So, the new flow would be:

1. If create_topic and create_subscriptions are both true (default) it creates both.
2. If only create_subscriptions is true, only create subscriptions.
3. If only create_topic is true, only create topic.

Changes pushed. Can you take a look ?