feat: Support standard environment variables

[PSanetra]

Closes #81

Changes

• Make previously required parameters of oauth_channel.create_oauth2_client_credentials_channel() and oauth_channel.create_camunda_cloud_channel() optional

API Updates

New Features (required)

oauth_channel.create_oauth2_client_credentials_channel() and oauth_channel.create_camunda_cloud_channel() support the following environment variables:

• ZEEBE_ADDRESS
• CAMUNDA_CLUSTER_ID
• CAMUNDA_CLUSTER_REGION
• CAMUNDA_CLIENT_ID
• ZEEBE_CLIENT_ID
• CAMUNDA_CLIENT_SECRET
• ZEEBE_CLIENT_SECRET
• CAMUNDA_OAUTH_URL
• ZEEBE_AUTHORIZATION_SERVER_URL
• CAMUNDA_CREDENTIALS_SCOPES
• CAMUNDA_TOKEN_AUDIENCE
• ZEEBE_TOKEN_AUDIENCE

Checklist

• Unit tests
• Documentation

[CLAassistant]

All committers have signed the CLA.

[coveralls]

Pull Request Test Coverage Report for Build 11739142105

Details

• 74 of 74 (100.0%) changed or added relevant lines in 5 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 97.117%

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Totals
Change from base Build 11659466005:	0.2%
Covered Lines:	1078
Relevant Lines:	1110

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💛 - Coveralls

[felicijus]

@dimastbk I would like to check the Camunda Cloud implementation side of this again, review should be in tomorrow.

@PSanetra thank you, you were quicker I also had this planned as a pull-request.

[felicijus]

Let's wait for #514 and #510 to be closed.

[felicijus]

Looks promising. 🚀

[felicijus]

I will review again 🚀

[PSanetra]

@felicijus @dimastbk do you have time for another review?

[felicijus]

Sorry forgot to finish mine... Released it now. but thats not everything.

[felicijus]

This should cover everything for now.

If we use a sentinal like this:

Unset = str("UNSET")

We solve the problem of None as a valid value and pseudo Optional arguments, meaning we can eliminate them.
This means for real Optional arguments the User can define None as a valid value. 🤖

[PSanetra]

@felicijus I have applied your latest suggestions, but needed to make some adjustments. E.g. the functions get_zeebe_address, get_camunda_oauth_url, get_camunda_cluster_region and get_camunda_token_audience need to have an optional default_value argument, which need to be considered as fallback in the case of usages in create_camunda_cloud_channel,

Also I have seen that version 4.0.0 was released, so I think the change of argument order in create_camunda_cloud_channel and probably also the introduction of the new Unset default values need to be considered as breaking changes.

[felicijus]

Thank you. I will look into it this afternoon.
But i think handing over the default value is quite nice ✅.

[felicijus]

Docs will be done by you @PSanetra ?

[PSanetra]

@felicijus I can do that, but I am not sure where to put them. Do you have a suggestion? I think it should generally be just documentation of the supported environment variables, right?

[felicijus]

Yes general support with what is supported as a seperate section, and add a short description to each channel creating function and the defaults used.

About the breaking changes, yes and no... At least for the oauth channel creation - no. There was no support for Environment variables at all and you also had no imposter None as default. ✅
For create_secure_channel and create_insecure_channel it can be considered a breaking change. ⚠️

So I guess 4.1.0 or whatever @dimastbk decides.

[felicijus]

✅ Maybe try to reach higher test coverage.

[PSanetra]

@felicijus I have added some documentation can you review it? I did not write reStructuredText docs before.

I have also added some tests which should improve coverage.

[felicijus]

I suggested some changes...

Please add this to the end of docs/channels_reference.rst to complete Channel Reference.

Utilities (Environment) 
-----------------------

.. autofunction:: pyzeebe.channel.utils.get_zeebe_address

.. autofunction:: pyzeebe.channel.utils.get_camunda_oauth_url

.. autofunction:: pyzeebe.channel.utils.get_camunda_client_id

.. autofunction:: pyzeebe.channel.utils.get_camunda_client_secret

.. autofunction:: pyzeebe.channel.utils.get_camunda_cluster_id

.. autofunction:: pyzeebe.channel.utils.get_camunda_cluster_region

.. autofunction:: pyzeebe.channel.utils.get_camunda_token_audience

.. autofunction:: pyzeebe.channel.utils.get_camunda_address

[PSanetra]

@felicijus Alright I have applied the suggestions

[felicijus]

Missed some rst formatting.

Inline code:

``"localhost:26500"``

After that we are done I think. ✅

[PSanetra]

@felicijus Alright I have applied that suggestion as well. I think when you want to merge this PR it makes sense to squash all the commit into one.

[felicijus]

Nice one. ✅

@dimastbk Please have a look and see if this can be released in 4.0.x...

[PSanetra]

@dimastbk I have rebased the PR onto master. I have also fixed the linting issues, found in the CI, but I am not sure were you found the errors, regarding the indentation in the docs.

[PSanetra]

@dimastbk I have resolved the remaining indentation issues.

[dimastbk]

Thanks!

And @felicijus thanks for review