My containers don't want to talk to each other. What am I missing?

[NAS Newbie]

I've been working on getting PhotoPrism and Paperless up and running with my brother in law for the last couple weeks off and on. My BIL is a sharp dude who works with containers and docker for a living. We cannot get PhotoPrism to talk to MariaDB and we cannot get Paperless to talk to Redis. He has taken the docker-compose files from my NAS and tried them on his own non-synology environment and they are working fine. Are we missing some sort of Synology firewall setting or something that is blocking communication from the app container to the database containers? Is there any way my ubiquiti firewall is somehow blocking communication?

 

[WST16]

Turn off the firewall and try. If it works, then all you need to do is add an “allow” for that particular subnet.

 

[NAS Newbie]

Turn off the firewall and try. If it works, then all you need to do is add an “allow” for that particular subnet.

We've tried adding an allow. I might temporilly disabled the entire syno firewall and see what happens. Maybe we are missing something with the net.

 

[Telos]

Probably unrelated, but my Docker bridge network corrupted a day or so ago, so containers that used to address one another are badly broken. I'm getting concerned that Synology is giving us "silent" update patches which are futzing with everything.

 

[NAS Newbie]

Disabling the firewall completely allowed document upload in paperless. The redis container must be on a different subnet that what we think it is. Will have to do more investigating.

 

[WST16]

A quick way is to go Docker > Network to check the subnet used by each container.

 

[NAS Newbie]

It looks like we have the correct subnet, but I must have set up the firewall rule incorrectly. Probably going to work with my BIL again in a day or two, we'll check it out then. Thanks.

 

[Rusty]

Probably unrelated, but my Docker bridge network corrupted a day or so ago, so containers that used to address one another are badly broken. I'm getting concerned that Synology is giving us "silent" update patches which are futzing with everything.

Your probable problem is IPTables being messed up. 99% sure we are not getting silent updates.