Joining multiple NS7 systems with the same account provider to NS8 fails

[nrauso]

In some NS7-to-NS8 migration scenarios, you may have multiple NS7 systems (e.g., NS7_1, NS7_2, and NS7_3) that share the same account provider.
For instance, NS7_1 might have Active Directory onboard, with NS7_2 and NS7_3 joined to NS7_1 to access the same user base.
In such cases, you should be able to migrate all services to NS8, joining NS7_1, NS7_2, and NS7_3 to NS8 simultaneously.
However, after joining NS7_1 (the first NS7 that needs to be joined), attempts to join the other NS7 systems fail.

Steps to reproduce

• Prepare two NS7 systems: set up the first one with an AD account provider, and join the second NS7 to the AD of the first;
• Install a new NS8 system;
• Install the NS8 migration tool on both NS7 systems;
• Join the first NS7 to NS8;
• Attempt to join the second NS7 to NS8.

Expected behavior

Both NS7 systems should join NS8 successfully

Actual behavior

The second NS7 fails to join NS8, displaying an error related to the external user domain.:

Components

NS8:

- core:3.2.2

NS7:

- nethserver-ns8-migration-1.0.17-1.ns7.x86_64

[nethbot]

in 7.9.2009/testing:

• nethserver-ns8-migration-1.0.17-1.4.g96bfaca.ns7.x86_64.rpm x86_64

[nrauso]

tested: VERIFIED

[nethbot]

in 7.9.2009/updates:

• nethserver-ns8-migration-1.0.18-1.ns7.x86_64.rpm x86_64