Comment 13 for bug 1931481

Added for the vault charm:

Issue: vault charm is installed and has been working in a system. System fails a power outage; mysql is not available when the vault charm comes back from cold-start; install hook fails.

What should happen; charm should enter a blocked state until the mysql server has returned. This may mean that the mysql charm may need to signal to the vault charm that it is 'back' (i.e. generate a hook execution).