[Feat]: Add placeholder in repositories for private user / group space

[Skiepp]

Is your feature request related to a problem? Please describe.

If I want to give a user a private space based on the username, like a private space for "bob" and "bananaJoe" I have to list all the users in the zot config file (which isn't a scalable solution):

"accessControl": {
    "bob/*": {
      "policies": [{
        "users": ["bob"],
        "actions": ["read", "create", "update"]
      }],
      "defaultPolicy": []
    },
    "bananaJoe/*": {
      "policies": [{
        "users": ["bananaJoe"],
        "actions": ["read", "create", "update"]
       }]
      "defaultPolicy": []
    }, ...
}

Describe the solution you'd like

Implement a simple placeholder mechanism for the repository name (following the very important pr 1123 for issue #983). An example configuration would be:

"accessControl": {
    "$repository/*": {                 <----
      "policies": [{
        "users": ["$repository"],      <----
        "groups": ["$repository"],
        "actions": ["read", "create", "update"]
      }],
      "defaultPolicy": []
    },
    "public/*": {
      "policies": [],
      "defaultPolicy": ["read", "create", "update"]
     }, ...
}

In the example above we have the users:

• bob in group foo
• bananaJoe in groups foo, bar

The ACL would be:

• Repository bob/* can be accessed by bob
• Repository bananaJoe/* can be accessed by bananaJoe
• Repository foo/* can be accessed by bob and bananaJoe (and other users in foo group)
• Repository bar/* can be accessed by bananaJoe (and other users in bar group)
• Repository public/* can be accessed by anyone

Describe alternatives you've considered

An alternative configuration would be to create two specific placeholder for user and group, for example:

"accessControl": {
    "$user/*": {               <----
      "policies": [{
        "users": ["$user"],    <----
        "actions": ["read", "create", "update"]
      }],
      "defaultPolicy": []
    },
    "$group/*": {               <----
      "policies": [{
        "groups": ["$group"],   <----
        "actions": ["read", "create", "update"]
       }]
      "defaultPolicy": []
    },
    "public/*": {
      "policies": [],
      "defaultPolicy": ["read", "create", "update"]
     }, ...
}

Additional context

No response

[rchincha]

Thanks @Skiepp for filing the issue. We are looking at this.

[aokirisaki]

We are currently working on it, but we have encountered a problem- we cannot map the names of the users directly to the names of the repositories, as the repositories' names have restrictions in what characters they can contain, which do not apply to the users.