streaming to chromecast from within container requires --net=host otherwise an incorrect server address is used
VLC 3.0.16 in a Fedora 34 container.
When running VLC in a container and a chromecast render, the automatically detected host name/ip is incorrect, it is the internal bridge IP. There is no ability to set a correct hostname for this value.
docker run --rm -it -p 8010:8010/tcp quay.io/galexrt/vlc:latest rtmp://nginx:1935/live/test --sout "#chromecast{ip=192.168.20.105}" --verbose 2
[00007f6400000d90] stream_out_chromecast stream out debug: Loading content
[00007f6400000d90] stream_out_chromecast stream out debug: Media receiver application has been started.
[00007f6400000d90] stream_out_chromecast stream out debug: s_chromecast_url: http://172.17.0.3:8010/chromecast/171536457722/1919024027/stream
[00007f6400000d90] stream_out_chromecast stream out debug: PING received from the Chromecast
The chromecast will attempt to connect to VLC, but never actually be able to connect since the IP is the internal bridge device.
Work-around is to use --net=host
so that the chromecast can contact VideoLan properly.
Perhaps the http-port/http-host/https-host CLI arguments could be applicable (I'm not familiar with their purpose). Or an option to the renderer to set-up a proper externally visible address.