Introduce WithEnvironment overload for custom connection string keys #3002

[danikishin]

This PR introduces a new overload for WithEnvironment method in the ResourceBuilderExtensions class, which allows setting the connection string of a resource under a custom environment variable name.

Changes

• Added WithEnvironment overload to accept a custom environment variable name.

Background

The issue #3002 describes a scenario where existing projects do not use the 'ConnectionStrings__' prefix for environment variables.

Example Usage

builder.AddProject<Projects.Web>("web").WithEnvironment("CustomEnvVarName", redis);
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[danikishin]

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[davidfowl]

This should have tests. Look at the existing WithEnvironment tests

[mitchdenny]

/backport to release/8.0

[github-actions]

Started backporting to release/8.0: https://github.com/dotnet/aspire/actions/runs/8626583440

[github-actions]

@mitchdenny backporting to release/8.0 failed, the patch most likely resulted in conflicts:

$ git am --3way --ignore-whitespace --keep-non-patch changes.patch

Applying: Update ResourceBuilderExtensions.cs
Applying: Update ResourceBuilderExtensions.cs
Applying: Update ResourceBuilderExtensions.cs
Applying: Update src/Aspire.Hosting/ResourceBuilderExtensions.cs
Applying: Remove async keyword
error: sha1 information is lacking or useless (src/Aspire.Hosting/ResourceBuilderExtensions.cs).
error: could not build fake ancestor
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0005 Remove async keyword
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[github-actions]

@mitchdenny an error occurred while backporting to release/8.0, please check the run log for details!

Error: git am failed, most likely due to a merge conflict.