ERR_CONNECTION_REFUSED Duplicati install portainer

How are you testing this? Where (in the network sense) is the machine you are trying to connect from with respect to the machine you are trying to connect to?

Actually that is what I wanted to know. Traffic between machines connected to a switch in a LAN isn't seen by your router, so looking there will yield nothing.

What happens if from the omv machine you telnet to its IP address on port 8443 ?

All of these suggest to me that the port is not open. Double check your docker creations and verify the host and container ports are really set to the ones you think they are.

You are correct, it is listening on port 8300. Too bad it is listening on TCP IPv6, and not IPv4. Fix that.

You mentioned changing the port for Duplicati from 8200 to 8300 because of a conflict with some other application. My guess is that this substitution was not done properly.

What application web page do you connect to when using port 8200?

Examine the docker logs for both Duplicati and Unifi Controller. Look for anything abnormal, especially things like problematic IP address binds and port conflicts.

You are going to have to eventually post how each container was configured. This will not be convenient using Portainer. But when asked for this it will be up to you to provide it.

I'll suggest this now, to get it out of the way. Don't use Portainer to initially create docker containers unless you can use the Stacks option where you can paste in a properly defined V 2.x or earlier compose file. You will want to begin with the sample compose files that are usually provided in various docker documentation pages. Copy and paste the sample file into a text document and edit it to be valid for your purposes. This will end up being a plain English text file, easily edited, and human readable. Once you think you have a proper file you can use it in a Stack creation in Portainer by pasting it in the Stack compose window. Then deploy the Stack and see what happens.

If you can't find a compose file for the container you wish to use and can't or won't compose one yourself, then use either a properly edited docker create command or docker run command pasted into a terminal shell.

It makes little difference what method you use to create containers. Portainer will become aware of them even if it wasn't used in the creation process.

Then you can use Portainer to make any additional edits or corrections, make copies of containers, start, stop, read logs, etc.

Having said this it's now time for you to provide how your containers were created - the actual inputs. Don't say things like I followed some video exactly. Provide what is being asked for.

Question: Do PUID=1000 and PGID=100 correspond to an existing user and group on your system?

Unless you need to provide CLI_ARGS I suggest deleting the line entirely. Might be OK to leave it as is but if you need to know for sure try putting it back in once you get the container working properly and see if that one change now breaks anything.

ports:

- 8300:8300 (host port : container port)

I suggest never ever changing the container port unless there is some well known and understood reason to do so. Such a change might not be supported by the container. Wouldn't be the first time I have seen a container port change break things. I will admit that it looks like the logical thing to do though.

Change this to:

8300:8200

You're welcome.

That's the beauty of posting the actual compose file you used. Took me seconds to spot that.

Food for thought: What if that compose file was in your first post?

Here's a hint for a tool you might find helpful. It will examine a running container, then create and spit out its docker compose file.

Just run it in the shell. Change the container name as needed. You can create a bash alias to have it available in the shell at all times. And you can redirect the output to a file.

docker run --rm -v /var/run/docker.sock:/var/run/docker.sock red5d/docker-autocompose:latest duplicati