feat: add credential_type plugin config

[JeyJeyGao]

Feat:

• added creential_type plugin config key
• supported credential type: default, environment, managedidentity, azurecli

Test:

• unit test cases
• e2e test cases
• tested environment credential, workload identity credential, managed identity in pod of AKS
• tested Azure cli credential locally

Resolves #146 #154
Signed-off-by: Junjie Gao [email protected]

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.65%. Comparing base (b838f3d) to head (b6f82d6).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #157      +/-   ##
==========================================
+ Coverage   91.22%   91.65%   +0.43%     
==========================================
  Files          16       17       +1     
  Lines         581      599      +18     
  Branches       72       74       +2     
==========================================
+ Hits          530      549      +19     
+ Misses         38       37       -1     
  Partials       13       13              

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[Two-Hearts]

So before this PR, i.e., before adding plugin config credential_type, how does a Notation user specify their credential_type?

[JeyJeyGao]

So before this PR, i.e., before adding plugin config credential_type, how does a Notation user specify their credential_type?

through this flag: --plugin-config credential_type=xxxx

[Two-Hearts]

I'm a bit confused, added credential_type plugin config key means this key is added in this PR right? My question is what's the behavior BEFORE this PR?

[JeyJeyGao]

I'm a bit confused, added credential_type plugin config key means this key is added in this PR right? My question is what's the behavior BEFORE this PR?

Before this PR, users could not set credential_type; it was chosen automatically by the library.
https://learn.microsoft.com/en-us/dotnet/api/azure.identity.defaultazurecredential?view=azure-dotnet

[Two-Hearts]

LGTM

[shizhMSFT]

LGTM. Is the plugin config credential_type documented anywhere?

[JeyJeyGao]

LGTM. Is the plugin config credential_type documented anywhere?

Added documents.