Docker container with multiple network interfaces: get only one IP address - docker

Question

I have a docker container named some-mysql, attacched to an overlay network named mynet: when i do docker inspect some-mysql it shows me this huge JSON:
{
"Id": "49cb39a4e8e5e7421a4ae69ffd5bb17a8f90f02abbfc3f64ef80d206ceb11c1f",
"Created": "2017-02-24T09:21:50.237425126Z",
"Path": "docker-entrypoint.sh",
"Args": [
"mysqld"
],
"State": {
"Status": "running",
"Running": true,
"Paused": false,
"Restarting": false,
"OOMKilled": false,
"Dead": false,
"Pid": 28706,
"ExitCode": 0,
"Error": "",
"StartedAt": "2017-03-27T06:59:40.137554407Z",
"FinishedAt": "2017-03-25T00:05:46.938307695Z"
},
"Image": "sha256:7666f75adb6b50676a366c6fd7a3916cb41f6e8eaf336c3d3ab7d35317fed0b9",
"ResolvConfPath": "/var/lib/docker/containers/49cb39a4e8e5e7421a4ae69ffd5bb17a8f90f02abbfc3f64ef80d206ceb11c1f/resolv.conf",
"HostnamePath": "/var/lib/docker/containers/49cb39a4e8e5e7421a4ae69ffd5bb17a8f90f02abbfc3f64ef80d206ceb11c1f/hostname",
"HostsPath": "/var/lib/docker/containers/49cb39a4e8e5e7421a4ae69ffd5bb17a8f90f02abbfc3f64ef80d206ceb11c1f/hosts",
"LogPath": "/var/lib/docker/containers/49cb39a4e8e5e7421a4ae69ffd5bb17a8f90f02abbfc3f64ef80d206ceb11c1f/49cb39a4e8e5e7421a4ae69ffd5bb17a8f90f02abbfc3f64ef80d206ceb11c1f-json.log",
"Name": "/some-mysql",
"RestartCount": 0,
"Driver": "aufs",
"MountLabel": "",
"ProcessLabel": "",
"AppArmorProfile": "",
"ExecIDs": null,
"HostConfig": {
"Binds": null,
"ContainerIDFile": "",
"LogConfig": {
"Type": "json-file",
"Config": {}
},
"NetworkMode": "default",
"PortBindings": {
"3306/tcp": [
{
"HostIp": "",
"HostPort": "3307"
}
]
},
"RestartPolicy": {
"Name": "no",
"MaximumRetryCount": 0
},
"AutoRemove": false,
"VolumeDriver": "",
"VolumesFrom": null,
"CapAdd": null,
"CapDrop": null,
"Dns": [],
"DnsOptions": [],
"DnsSearch": [],
"ExtraHosts": null,
"GroupAdd": null,
"IpcMode": "",
"Cgroup": "",
"Links": null,
"OomScoreAdj": 0,
"PidMode": "",
"Privileged": false,
"PublishAllPorts": false,
"ReadonlyRootfs": false,
"SecurityOpt": null,
"UTSMode": "",
"UsernsMode": "",
"ShmSize": 67108864,
"Runtime": "runc",
"ConsoleSize": [
0,
0
],
"Isolation": "",
"CpuShares": 0,
"Memory": 0,
"NanoCpus": 0,
"CgroupParent": "",
"BlkioWeight": 0,
"BlkioWeightDevice": null,
"BlkioDeviceReadBps": null,
"BlkioDeviceWriteBps": null,
"BlkioDeviceReadIOps": null,
"BlkioDeviceWriteIOps": null,
"CpuPeriod": 0,
"CpuQuota": 0,
"CpuRealtimePeriod": 0,
"CpuRealtimeRuntime": 0,
"CpusetCpus": "",
"CpusetMems": "",
"Devices": [],
"DiskQuota": 0,
"KernelMemory": 0,
"MemoryReservation": 0,
"MemorySwap": 0,
"MemorySwappiness": -1,
"OomKillDisable": false,
"PidsLimit": 0,
"Ulimits": null,
"CpuCount": 0,
"CpuPercent": 0,
"IOMaximumIOps": 0,
"IOMaximumBandwidth": 0
},
"GraphDriver": {
"Name": "aufs",
"Data": null
},
"Mounts": [
{
"Type": "volume",
"Name": "c709191cb719b447772bde814f490eb2b30429c9ca7f1c62fda445af9e0b5fb9",
"Source": "/var/lib/docker/volumes/c709191cb719b447772bde814f490eb2b30429c9ca7f1c62fda445af9e0b5fb9/_data",
"Destination": "/var/lib/mysql",
"Driver": "local",
"Mode": "",
"RW": true,
"Propagation": ""
}
],
"Config": {
"Hostname": "49cb39a4e8e5",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"ExposedPorts": {
"3306/tcp": {}
},
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"MYSQL_ROOT_PASSWORD=pass",
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"GOSU_VERSION=1.7",
"MYSQL_MAJOR=5.7",
"MYSQL_VERSION=5.7.17-1debian8"
],
"Cmd": [
"mysqld"
],
"ArgsEscaped": true,
"Image": "mysql",
"Volumes": {
"/var/lib/mysql": {}
},
"WorkingDir": "",
"Entrypoint": [
"docker-entrypoint.sh"
],
"OnBuild": null,
"Labels": {}
},
"NetworkSettings": {
"Bridge": "",
"SandboxID": "1f5cde48c303e649f0b675ac11f302336936c7ea0f7c1a0ea8054866c308189d",
"HairpinMode": false,
"LinkLocalIPv6Address": "",
"LinkLocalIPv6PrefixLen": 0,
"Ports": {
"3306/tcp": [
{
"HostIp": "0.0.0.0",
"HostPort": "3307"
}
]
},
"SandboxKey": "/var/run/docker/netns/1f5cde48c303",
"SecondaryIPAddresses": null,
"SecondaryIPv6Addresses": null,
"EndpointID": "2800343c29643796d28e8f58a13a7dbf5d1a2706d26f25e27ea623a4673d4439",
"Gateway": "172.17.0.1",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"IPAddress": "172.17.0.3",
"IPPrefixLen": 16,
"IPv6Gateway": "",
"MacAddress": "02:42:ac:11:00:03",
"Networks": {
"bridge": {
"IPAMConfig": null,
"Links": null,
"Aliases": null,
"NetworkID": "a3ec63c75685ca69af892f7047abc2c1d0955407d61423f2cff87500eedaadf3",
"EndpointID": "2800343c29643796d28e8f58a13a7dbf5d1a2706d26f25e27ea623a4673d4439",
"Gateway": "172.17.0.1",
"IPAddress": "172.17.0.3",
"IPPrefixLen": 16,
"IPv6Gateway": "",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"MacAddress": "02:42:ac:11:00:03"
},
"mynet": {
"IPAMConfig": {},
"Links": null,
"Aliases": [
"49cb39a4e8e5"
],
"NetworkID": "37af7ae0184078932bbc234c1f4b15983777f566c36f7eb93e2b4b3437e460a7",
"EndpointID": "fd1f776954723a705edef323b63588cfc93cca7b80b15f22414b72454e14e48c",
"Gateway": "172.18.0.1",
"IPAddress": "172.18.0.2",
"IPPrefixLen": 16,
"IPv6Gateway": "",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"MacAddress": "02:42:ac:12:00:02"
}
}
}
}
]
My goal is to get only IP address of some-mysql container related to network interface mynet. If I do
docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' some-mysql
I get: 172.17.0.3172.18.0.2 : they are IP addresses of default bridge network and my overlay network. How can i retrieve only some-mysql IP address of mynet interface?

Answer 1

You can specify the network name, without needing of range:
docker inspect -f '{{.NetworkSettings.Networks.mynet.IPAddress}}' some-mysql