Periodically poll registries and pull images according to sync's config
Added sync on demand, syncing when clients asks for an image which
zot doesn't have.
Signed-off-by: Petu Eusebiu <peusebiu@cisco.com>
Some LDAP servers are not MT-safe in that when searches happen with binds
in flight leads to errors such as:
"comment: No other operations may be performed on the connection while a
bind is outstanding"
Add goroutine-id in logs to help debug MT bugs.
Signed-off-by: Ramkumar Chinchani <rchincha@cisco.com>
