Different configs, 500 error keeps repeating (TLDR)

Using Dokku on DO/Ubuntu 16.04 and latest Docker, Dokku, Shinyproxy. Pushing the Dockerfile example for “Shinyproxy as a container” to server which has an Nginx reverse proxy (hosting some other Shiny, Plumber api dev apps running without issue).

Shinyproxy launches, I can login and don’t get any errors but every attempt to start test apps ends in a 500 error and ’ javax.ws.rs.ProcessingException: java.io.IOException: No such file or directory’. Checking the logs doesn’t surface anything which makes me believe it is a networking issue. I have set up the docker innards to run off but I can’t seem to find out where to initialize the internal networking? The template shows two settings in the docker file, 1) the initial docker container “internal-networking: true” and 2) the app(s) level “docker-network: sp-example-net”.

My second though was the firewall is blocking port 8080. Turn it on with Iptables rule and not sure if it stuck. As a matter of philosophy, I don’t understand why 8080 would need to be open anyway if everything is done within confines of a single server?

No problems launching on local machine or launching as standalone docker containers on remote.


I should mention the host has the demo image which I believe SP accesses directly to launch?

Did you mount the volume /var/run/docker.sock:/var/run/docker.sock? We faced the same error and missed exactly that.