Ex2.4: Docker Network

README.md

Ex2.4: Docker Network

List all docker networks

$ docker network ls

** sample output **

NETWORK ID          NAME                DRIVER              SCOPE
0a34ec3a4f58        bridge              bridge              local
5452c8e97607        host                host                local
d6a1ef964756        none                null                local

Inspect 'bridge' default docker virtual network

$ docker network inspect bridge

sample output:

[
    {
        "Name": "bridge",
        "Id": "0a34ec3a4f58edd8aa7ad46bdd8946c9275a1f5b72c2bbc36d2e5ebfe6e836ee",
        "Created": "2018-08-21T11:01:29.148832762Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.17.0.0/16"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {},
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]

Create two alpine linux containers: alpine1, alpine2

$ docker container run -d --name alpine1 alpine
$ docker container run -d --name alpine2 alpine

Inspect the 'bridge' network again

$ docker network inspect bridge

sample output:

[
    {
        "Name": "bridge",
        "Id": "0a34ec3a4f58edd8aa7ad46bdd8946c9275a1f5b72c2bbc36d2e5ebfe6e836ee",
        "Created": "2018-08-21T11:01:29.148832762Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.17.0.0/16"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "5f4b98a4dfbd93807a3c0c8fd614a9102e253b79439c068c75bbc4f264464fad": {
                "Name": "my_alpine",
                "EndpointID": "7b602fd7b979fae9b46f809d813b7c54ad3e4250df73a388d79b8e47a9ceb899",
                "MacAddress": "02:42:ac:11:00:02",
                "IPv4Address": "172.17.0.2/16",
                "IPv6Address": ""
            },
            "df230c9bc75b40cbd5ee4452c5fe3207c6decb25ecf33f93b29bf83111159821": {
                "Name": "my_alpine2",
                "EndpointID": "ef90389287f9dbaeae9f3c99f1742a14377ac3a19e3d1b633376f73ebcac235c",
                "MacAddress": "02:42:ac:11:00:03",
                "IPv4Address": "172.17.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]

Attach the terminal to alpine2 container

$ docker container attach alpine2

within the container, checking network configuration and status:

/# ifconfig               // check network interfaces
/# route -n               // check routing table
/# ping www.google.com    // check DNS
/# ping 
/# ping 
/# ping alpine1

exits the alpine2 container using 'Ctrl+pq'.

Create 'net1' virtual network and list all virtual network again.

$ docker network create net1
$ docker network ls

NETWORK ID          NAME                DRIVER              SCOPE
0a34ec3a4f58        bridge              bridge              local
5452c8e97607        host                host                local
9a4dde6f2498        net1                bridge              local
d6a1ef964756        none                null                local

Connect alpine1 and alpine2 to 'net1' virtual network. Inspect the 'net1' network.

$ docker network connect net1 alpine1
$ docker network connect net1 alpine2
$ docker network inspect net1

sample output:

[
    {
        "Name": "net1",
        "Id": "9a4dde6f2498f46819c6e7d2da98c46e36d6ed5d866403be62aa54a8e99efc80",
        "Created": "2018-08-21T11:20:49.992829738Z",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "172.18.0.0/16",
                    "Gateway": "172.18.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "5f4b98a4dfbd93807a3c0c8fd614a9102e253b79439c068c75bbc4f264464fad": {
                "Name": "my_alpine",
                "EndpointID": "7ab05e8cf5032311de3af4b89483810b7849946158600866d2ffde93836cdc8f",
                "MacAddress": "02:42:ac:12:00:02",
                "IPv4Address": "172.18.0.2/16",
                "IPv6Address": ""
            },
            "df230c9bc75b40cbd5ee4452c5fe3207c6decb25ecf33f93b29bf83111159821": {
                "Name": "my_alpine2",
                "EndpointID": "398d5704764628b2fc231dc8b81730819a47b483898873d96f8f3dc507660c83",
                "MacAddress": "02:42:ac:12:00:03",
                "IPv4Address": "172.18.0.3/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]

Now attach the terminal to 'alpine2' container and test everything again. What are the difference?