KVM + Docker Swarm

[max78]

Hello,


I have installed Debian 11 in the KVM and inside I like to use Docker Swarm.

Docker works without problems.

But if I use Swarm, I can’t access the exposed Ports from outside.
I tried NGINX to Port 8080 and Portainer. Both doesn’t work from outside. From inside the KVM I can reach this ports.
From outside the KVM I can reach (the same) normal docker ports, with swarm I can’t reach the ports.

Does anyone know a solution?


Thanks, Markus

 

[shrdlicka]

How did you check the connection? Did you try something like "telnet host/ip port"?

 

[max78]

I tried it with a browser in windows in the same network. (the normal docker container works there)
In the KVM it works with curl.

 

[shrdlicka]

Can you connect to it when you disable the firewall on the network device?

 

[max78]

the firewall in Proxmox is disabled

 

[shrdlicka]

hm ... it might be that it is binding to the wrong interface

 

[max78]

the interesting thing is that docker is working and swarm not

 

[LnxBil]

Have you created the special network mode in order to get working docker swarm? I haven't used it for years (swarm is dead) and I cannot remember what I did exactly, but I remember that just easy-peasy docker-compose up did not do the trick. There was something else involved in creating a special network layer in order to get it to work. Hope that helps at least a little bit.

 

[max78]

I thought normal swarm setup is enough, because docker is running fine.
It’s my first swarm setup. I didn’t changed the network layers… This would be the problem.

I like to setup some docker container for HA use.

I thought it’s easy with swarm because of the integrated load balancer. But I now know I have do use something like HAProxy. And for some containers, like Mysql it’s even more difficult.

What do you recommend instead of swarm? Kubernetes?

 

[LnxBil]

Kubernetes?

Yes!