Add AZURE_LOCATION as default --location in capi create

[tal66]

Hi, this closes #120.

When --location isn't specified, it's now determined by:

1. config file [defaults]
2. resource-group
3. AZURE_LOCATION
4. still None -> raise RequiredArgumentMissingError

Did I miss anything?

Edit: actually when i think about it, maybe it makes more sense to have config file [defaults] and AZURE_LOCATION both either before resource-group or both after..

[ghost]

All CLA requirements met.

[tal66]

changed the order to:

1. config file [defaults]
2. AZURE_LOCATION
3. checked against resource-group (if exists)
4. raise Error

for existing rg, maybe it would make more sense to just take the rg loaction. but i used the above order because:

a. before my pr, the config file is used first
b. since this project is an extension, i'm not sure how to check if the location came from the config file or from the cli

[DannyBrito]

Hello @tal66

The order that you presented is correct to set value for location for az capi create method priority:

1. value passed with --location flag
2. value specified on config file defaults by az config set defaults.location=<location>
3. Environment variable AZURE_LOCATION
4. Use location if resource group provided exits

After looking at bit more I see that there might be a bug on check_resource_group method when the resource group is found we should use this location, as you mentioned, by returning it to az capi create. I have opened another issue about this! #144

You are definitely in the right track. However, this change should take place on create_workload_cluster method for az capi create command
It should be similar to setting the defaults of the other arguments.
And if --location is not passed on the cli the framework will retrieve the config defaults location value if exits so we only need to take care of AZURE_LOCATION:

azure-capi-cli-extension/src/capi/azext_capi/custom.py

Line 419 in 2a24f52

def create_workload_cluster( # pylint: disable=unused-argument,too-many-arguments,too-many-locals,too-many-statements

Thank you for your contribution 👍

[tal66]

I moved it to create_workload_cluster, but didn't set the location like the other parameters with a default - as this way is problematic to test. From what i see, once the module file is read those defaults are set, so by the time i mock an environment variable in the test, the default is already None (it's not checked again every call).

[mboersma]

lgtm! I tested this locally and this seems like the behavior we want. Thanks @tal66!

With this and #141, if you configure a default location or set AZURE_LOCATION, you can just do az capi create without any arguments.