Uniqueness Checks for ASN, sessions and routing policies

[liquid-metal]

When creating a new

• AS
• BGP session
• Routing Policy

duplicate entries will be created if there is already an object with the same properties.

[liquid-metal]

Had a quick look at the model, is there any reason the number property of ASN (or BGPBase to be more precise) is nullable and not unique?
For now, I have added the unique=True constraint to the field, which seems to work, but this is a breaking change for existing databases:

• There may already be multiple entries with same ASN
• There may be entries with ASN set to None

Trying to set null=False breaks the migration:

You are trying to change the nullable field 'number' on asn to non-nullable without a default; we can't do that (the database needs something to populate existing rows).

Unfortunately, I am not as comfortable with Django and its migrations, is there a possibility to resolve this?

[k01ek]

I think ASN shouldn't be unique. AS number is like a VLAN, you can use the same number for different purposes depending on device or site. Maybe it should use a combination of some fields to get unique.

[liquid-metal]

do you have a specific use case? In my understanding ASNs are global should always be unique.
For VLANs I see the point in having one set of VLANs per site (although I noticed netbox lets you create indistinguishable VLANs as well).
In any case, null should not be allowed for AS numbers (or am I mistaken?)