Hi Tom,
Yes, that was a typo the 2nd command should have been different. Thank you for pointing this out. I have updated the blog with the right command. which are:
adutil keytab createauto -k ~/container/mssql.keytab -p 1433 -H sqlinst1-0.contoso.com --password 'P@ssw0rd!' -s MSSQLSvc
adutil keytab create -k ~/container/mssql.keytab -p sqluser --password 'P@ssw0rd!'
Also, you can follow the documentation here as another reference: Configure Active Directory authentication with SQL Server on Linux-based containers using adutil - SQL Server | Microsoft Learn to configure AD authentication for SQL containers.
For the error message that you pasted, normally there should be something more above this to help identify the issue, could you please paste few more lines above and below the error messages, may be all the lines for a specific time repro, so I can see the details.