how do the nodes find each other?

[kumavis]

the docker configuration seems like they should not be able to communicate with each other

[kumavis]

what docker networks exist?

$ docker network ls
NETWORK ID          NAME                  DRIVER              SCOPE
cc0092f46b29        bridge                bridge              local
87dc86f8079a        host                  host                local
ef5afd8c4145        none                  null                local
5a968aaa4d53        ssbtutorial_default   bridge              local

network config (containers' local ip addresses):

$ docker network inspect ssbtutorial_default
[
    {
        "Name": "ssbtutorial_default",
        "Id": "5a968aaa4d530b6e554b68225da9e395107b70a1cb5b7d04a7e633fce8209c97",
        "Created": "2017-12-23T01:48:55.298206779Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.18.0.0/16",
                    "Gateway": "172.18.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": true,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "1960ab9d3ddc420ce937773446953a27ce4989dff628128657cd2a94e906df65": {
                "Name": "user2",
                "EndpointID": "c83f29bf460a6c3b6ee841cf7d9885e0fee2ec292ad85ce202119d4728c7f329",
                "MacAddress": "02:42:ac:12:00:02",
                "IPv4Address": "172.18.0.2/16",
                "IPv6Address": ""
            },
            "5e1a2dc9fa073ea03d88718217e7f078e172a8e749029bbfb120413e352736c5": {
                "Name": "pub",
                "EndpointID": "b85606d8b0463f3f601924f648806c915c6d86897fd164285aafe799b025ccf5",
                "MacAddress": "02:42:ac:12:00:04",
                "IPv4Address": "172.18.0.4/16",
                "IPv6Address": ""
            },
            "83a170a3ce695b5949e5418fbc988bc4acf616279921d0ca4758d814d7063831": {
                "Name": "user1",
                "EndpointID": "32b977706e266ab3cee94b42b9509e96505125ff476883cf6af60fd2f0f07a47",
                "MacAddress": "02:42:ac:12:00:03",
                "IPv4Address": "172.18.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {
            "com.docker.compose.network": "default",
            "com.docker.compose.project": "ssbtutorial"
        }
    }
]

active connections on machine:

$ ./cli-for user1
root@user1:/scuttlebot# ss  
Netid  State      Recv-Q Send-Q                               Local Address:Port                                   Peer Address:Port   
tcp    ESTAB      0      0                                ::ffff:172.18.0.3:8118                              ::ffff:172.18.0.2:54492   
tcp    ESTAB      0      0                                ::ffff:172.18.0.3:8118                              ::ffff:172.18.0.4:46518

[kumavis]

so i guess default docker settings are different than i thought - they are able to talk to each other by default