Add --base-url option to aio app init --repo

[obarcelonap]

Description

Closes adobe/aio-cli#695

Related Issue

Motivation and Context

In order to be able to use quickstarts in Github's Enterprise Server.

How Has This Been Tested?

Unit testing

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[purplecabbage]

This looks good, however, I would prefer it be done without an additional flag.
The current implementation mimics npm install [<package-spec> ...] in the way it interprets the package-spec
For example:

1. install an npm published + scoped package ( plus version options )
   npm i @adobe/aio-lib-state
2. install from github user/repo ( plus numerous branch options )
   npm i adobe/aio-lib-state
3. install from url (ssh)
   npm i git@github.com:adobe/aio-lib-state.git
4. install from url (https)
   npm i git@github.com:adobe/aio-lib-state.git

I think we should similarly overload the --repo flag to support these cases.

[obarcelonap]

@purplecabbage thanks for your feedback. I am not sure if we can mimic npm's behaviour since the repo option allows to reference specific directories (org/repo/dir)

In regards your examples:
opt 1 is out of the scope, because quickstarts are not published in any artifact repository
opt 2 is what is currently implemented
opt 3 and 4 would be feasible but from my perspective it would give the false impression that the plugin is using git clone command which is not. Actually I am not sure how we will reflect the subfolder in the repo for these cases.

I would not overcomplicate the implementation. This pull request seems a quick win for me to support github enterprise installation. While I agree your proposal is much nicer I believe it requires a redesign of the command specification which I am not sure if is worthy.

[obarcelonap]

@shazron @purplecabbage can I get your feedback based on my last comment?

If still is desired to use the npm approach, I was wondering how a concrete example would look like.

# prefix with github enterprise server url
aio app init --repo mygithub.com:myorg/myrepo/myfolder

# by default uses github (current behaviour)
aio app init --repo adobe/appbuilder-quickstarts/dne 

Is that sufficient from your perspective?