How to share host network bridge when using docker in docker -

i'm using https://github.com/jpetazzo/dind docker image have docker in docker. when starting docker containers inside parent docker, possible use bridge of parent docker can share network between containers inside docker container , parent docker container?

what want access containers inside parent docker container host directly ip assign domain names them.

update -> main idea

i'm upgrading free online java compiler allow users run program using docker. i'm using dind (docker in docker image) launch main container have inside java program receive requests , launch docker containers inside of it. want give users option run programs expose port , let them access containers using subdomain. graphically have hierarchy

internet -> host -> main docker container -> user docker container 1                                              -> user docker container 2                                              -> user docker container n 

and want give user subdomain name access "user docker container" example: www.user_25.compiler1.browxy.com

so can have program expose port in "user docker container" , can access using subdomain www.user_25.compiler1.browxy.com

what confuses me access "user docker container" need access before main docker container. i'm trying find way access "user docker container" directly, thought if user docker container , main docker container can share same network can access user docker container directly host , assign domain name "user docker container" ip updating /etc/hosts file on host.

thanks lot advice or suggestion :)

if run "main docker container" --net=host, configuration simplifies to:

internet -> host -> user docker container 1                  -> user docker container 2                  -> user docker container n 

although want use bridge other docker0 child containers (e.g., create new bridge docker1, , start dind docker daemon -b docker1).

if 2 users attempt publish service on same port @ same ip address, yes, have port conflicts. there few ways of working around this:

1. if can support multiple public ip addresses on host, can "assign" (in quotes because not automatic) 1 each container. instead of running docker run -p 80:80 ..., need make bind ip explicit, docker run -p 80:80:1.2.3.4. requires people "play nice"; is, there nothing prevent either forgetting specify bind address or specifying wrong address.

2. if explicitly running web services, may able use sort of front-end proxy map subdomain names containers using name-based virtual host. there several components process, , making automated require little work. doing manually comparatively easy (just update /etc/hosts, example), fragile because when container restarted have new ip address. a dynamic dns service can this.

these suggestions more solutions, let me know if more details. there other ways of cracking particular nut, else chime in.