リンクバル技術部の川畑です。前回の記事UdemyでDockerを学ぶ③ 〜Section3〜（Docker Compose編）では、主にDocker Composeを利用したDockerコンテナのの管理について学びました。今回はDockerのネットワーク管理が中心となります。それでは見ていきましょう。
目次
「Section4: The Complete Docker Course for DevOps and Developers」の内容
Section4の内容は以下の通り。
- 24 Introduction to Docker Networking
- 25 None Network
- 26 Bridge Network
- 27 Host Network and Overlay Network
- 28 Define Container Networks with Docker Compose
24. Introduction to Docker Networking
- Docker Networkのタイプは4種類
- Closed Network / None Network
- Bridge Network
- Host Network
- Overlay Network
- デフォルトは「Bridge Network」
Docker Networkの確認
NETWORK ID NAME DRIVER SCOPE
cd6c5f3cd5d9 bridge bridge local
0193aefaa52c host host local
9f12416e8aeb none null local
ubuntu@ubuntu-xenial:~/dockerapp$
[/bash]
25. None Network
Unable to find image ‘busybox:latest’ locally
latest: Pulling from library/busybox
7520415ce762: Pull complete
Digest: sha256:32f093055929dbc23dec4d03e09dfe971f5973a9ca5cf059cbfb644c206aa83f
Status: Downloaded newer image for busybox:latest
5fb23f4e716999064a525b60f209e4547bd6af9f85cc0c46b61d8d911bbf7641
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it 5fb23f4e716999064a525b60f209e4547bd6af9f85cc0c46b61d8d911bbf7641 /bin/ash
/ # ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8): 56 data bytes
ping: sendto: Network is unreachable
/ # ifconfig
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
/ #
[/bash]
None Network
- Provides the maximum level of network protection.
- Not a good choice if network or Internet connection is required.
- Suites well where the container require the maximum level of network security and network access is not necessary.
26. Bridge Network
NETWORK ID NAME DRIVER SCOPE
0b31dea75498 bridge bridge local
bc985f2eed5d dockerapp_default bridge local
0193aefaa52c host host local
9f12416e8aeb none null local
ubuntu@ubuntu-xenial:~/dockerapp$ docker network inspect bridge
[
{
"Name": "bridge",
"Id": "0b31dea7549895f21d615eedbddf3f34f77deb39a2b8505c3fa0195b00cfc30f",
"Scope": "local",
"Driver": "bridge",
"EnableIPv6": false,
"IPAM": {
"Driver": "default",
"Options": null,
"Config": [
{
"Subnet": "172.17.0.0/16",
"Gateway": "172.17.0.1"
}
] },
"Internal": 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": {}
}
] ubuntu@ubuntu-xenial:~/dockerapp$
[/bash]
Subnetは”172.17.0.0/16″
f2c50e2ff99a800ec33771c72fcf8444ad6c7f9bbbe24d72c856e23b5393907e
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_1 ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:AC:11:00:02
inet addr:172.17.0.2 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:acff:fe11:2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:648 (648.0 B) TX bytes:648 (648.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
ubuntu@ubuntu-xenial:~/dockerapp$ docker run -d –name container_3 busybox sleep 1000
fd048b53724e954a3e4722aa8e882b40624df87a6ecde00cc868266182c72879
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_3 ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:AC:11:00:03
inet addr:172.17.0.3 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:acff:fe11:3/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:648 (648.0 B) TX bytes:648 (648.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_1 ping 172.17.0.3
PING 172.17.0.3 (172.17.0.3): 56 data bytes
64 bytes from 172.17.0.3: seq=0 ttl=64 time=0.143 ms
64 bytes from 172.17.0.3: seq=1 ttl=64 time=0.110 ms
64 bytes from 172.17.0.3: seq=2 ttl=64 time=0.100 ms
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_1 ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: seq=0 ttl=61 time=15.758 ms
64 bytes from 8.8.8.8: seq=1 ttl=61 time=14.039 ms
64 bytes from 8.8.8.8: seq=2 ttl=61 time=9.946 ms
[/bash]
bridge network作成
bb058af389823805a58c74d802145074586c3ee1ecc3069422caf26dc3ad6660
ubuntu@ubuntu-xenial:~/dockerapp$ docker network ls
NETWORK ID NAME DRIVER SCOPE
0b31dea75498 bridge bridge local
bc985f2eed5d dockerapp_default bridge local
0193aefaa52c host host local
bb058af38982 my_bridge_network bridge local
9f12416e8aeb none null local
ubuntu@ubuntu-xenial:~/dockerapp$ docker network inspect my_bridge_network
[
{
"Name": "my_bridge_network",
"Id": "bb058af389823805a58c74d802145074586c3ee1ecc3069422caf26dc3ad6660",
"Scope": "local",
"Driver": "bridge",
"EnableIPv6": false,
"IPAM": {
"Driver": "default",
"Options": {},
"Config": [
{
"Subnet": "172.19.0.0/16",
"Gateway": "172.19.0.1/16"
}
] },
"Internal": false,
"Containers": {},
"Options": {},
"Labels": {}
}
]
※新しく作成したnetworkを指定してcontainerを作成
ubuntu@ubuntu-xenial:~/dockerapp$ docker run -d –name container_4 –net my_bridge_network busybox sleep 1000
546adaecc4c4657182df944e99d9c2759113963d46378e4bae90868e83bca33b
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_4 ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:AC:13:00:02
inet addr:172.19.0.2 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:acff:fe13:2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1296 (1.2 KiB) TX bytes:648 (648.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
※別のnetworkへのpingは失敗
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_4 ping 172.17.0.2
PING 172.17.0.2 (172.17.0.2): 56 data bytes
^C
— 172.17.0.2 ping statistics —
48 packets transmitted, 0 packets received, 100% packet loss
ubuntu@ubuntu-xenial:~/dockerapp$
[/bash]
docker network connect
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_4 ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:AC:13:00:02
inet addr:172.19.0.2 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:acff:fe13:2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:18 errors:0 dropped:0 overruns:0 frame:0
TX packets:58 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1380 (1.3 KiB) TX bytes:5436 (5.3 KiB)
eth1 Link encap:Ethernet HWaddr 02:42:AC:11:00:02
inet addr:172.17.0.2 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:acff:fe11:2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:648 (648.0 B) TX bytes:648 (648.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_4 ping 172.17.0.2
PING 172.17.0.2 (172.17.0.2): 56 data bytes
64 bytes from 172.17.0.2: seq=0 ttl=64 time=0.050 ms
64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.046 ms
64 bytes from 172.17.0.2: seq=2 ttl=64 time=0.047 ms
[/bash]
docker network disconnect
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_4 ifconfig
eth0 Link encap:Ethernet HWaddr 02:42:AC:13:00:02
inet addr:172.19.0.2 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:acff:fe13:2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:18 errors:0 dropped:0 overruns:0 frame:0
TX packets:58 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1380 (1.3 KiB) TX bytes:5436 (5.3 KiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:672 (672.0 B) TX bytes:672 (672.0 B)
ubuntu@ubuntu-xenial:~/dockerapp$
[/bash]
Bridge Network
- In a bridge network, containers have access to two network interfaces.
- A loopback interface
- A private interface
- All containers in the same bridge network can communicate with each other.
- Containers from different bridge networks can’t connect with each other by default.
- Reduces the level of network isolation in favor of better outside connectivity.
- Most suitable where you want to setup a relatively small network on a single host.
27. Host Network and Overlay Network
Host Network
- The least protected network model, it adds a container on the host’s network stack.
- Containers deployed on the host stack have full access to the host’s interface
- This kind of containers are usually called open containers.
055a8818110db06b3fda5189a1036f6a4cf44360dbb20112cac731807ef1ac58
ubuntu@ubuntu-xenial:~/dockerapp$ docker exec -it container_5 ifconfig
br-bb058af38982 Link encap:Ethernet HWaddr 02:42:AA:D1:B4:A8
inet addr:172.19.0.1 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:aaff:fed1:b4a8/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:58 errors:0 dropped:0 overruns:0 frame:0
TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4624 (4.5 KiB) TX bytes:732 (732.0 B)
br-bc985f2eed5d Link encap:Ethernet HWaddr 02:42:30:C9:BE:0A
inet addr:172.18.0.1 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:30ff:fec9:be0a/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:54 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3384 (3.3 KiB) TX bytes:648 (648.0 B)
docker0 Link encap:Ethernet HWaddr 02:42:42:AD:7F:51
inet addr:172.17.0.1 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::42:42ff:fead:7f51/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:31938 errors:0 dropped:0 overruns:0 frame:0
TX packets:47396 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1478517 (1.4 MiB) TX bytes:111420104 (106.2 MiB)
enp0s3 Link encap:Ethernet HWaddr 02:1B:66:AB:E9:71
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::1b:66ff:feab:e971/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:470407 errors:0 dropped:0 overruns:0 frame:0
TX packets:221341 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:603222228 (575.2 MiB) TX bytes:91959788 (87.6 MiB)
enp0s8 Link encap:Ethernet HWaddr 08:00:27:39:AA:43
inet addr:192.168.33.11 Bcast:192.168.33.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe39:aa43/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:345 errors:0 dropped:0 overruns:0 frame:0
TX packets:208 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:43876 (42.8 KiB) TX bytes:178420 (174.2 KiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
[/bash]
※Hostとすべてのbridge networkのネットワークからアクセスできる
Host Network
- Minimum network security level.
- No isolation on this type of open containers, thus leave the container widely unprotected.
- Containers running in the host networkstack should see a higher level of performance than those traversing the docker0 bridge and iptables port mapings.
Overlay Network
- Supports multi-host networking out-of-the-box.
- Require some pre-existing conditions before it can be created.
- Running Docker engine in Swarm mode.
- A key-value store such as consul.
※プロダクションはOverlay Network
28 Define Container Networks with Docker Compose
Saved working directory and index state WIP on (no branch): b3823ad introduce docker compose
HEAD is now at b3823ad introduce docker compose
HEAD is now at b3823ad… introduce docker compose
※バックグランドで起動（初回起動時は「Creating network」が標準出力される）
ubuntu@ubuntu-xenial:~/dockerapp$ docker-compose up -d
Starting dockerapp_redis_1
Recreating dockerapp_dockerapp_1
ubuntu@ubuntu-xenial:~/dockerapp$ docker network ls
NETWORK ID NAME DRIVER SCOPE
0b31dea75498 bridge bridge local
bc985f2eed5d dockerapp_default bridge local
0193aefaa52c host host local
bb058af38982 my_bridge_network bridge local
9f12416e8aeb none null local
※Container停止
ubuntu@ubuntu-xenial:~/dockerapp$ docker-compose down
Stopping dockerapp_dockerapp_1 … done
Stopping dockerapp_redis_1 … done
Removing dockerapp_dockerapp_1 … done
Removing dockerapp_redis_1 … done
Removing network dockerapp_default
※docker-compose.ymlにnetwork追記
ubuntu@ubuntu-xenial:~/dockerapp$ vi docker-compose.yml
———-
version: ‘2’
services:
dockerapp:
build: .
ports:
– "5000:5000"
volumes:
– ./app:/app
networks:
– my_net
redis:
image: redis:3.2.0
networks:
– my_net
networks:
my_net:
driver: bridge
———-
※再度Containerを起動して指定したnetworkが作成されるか確認
ubuntu@ubuntu-xenial:~/dockerapp$ docker-compose up -d
Creating network "dockerapp_my_net" with driver "bridge"
Creating dockerapp_redis_1
Creating dockerapp_dockerapp_1
[/bash]
sample docker-compose.yml
services:
proxy:
build: ./proxy
networks:
– front
app:
build: ./app
networks:
– front
– back
db:
image: postgres
networks:
– back
networks:
front:
# Use a custom driver
driver: custom-driver-1
back:
# Use a custom driver which takes special options
driver: custom-driver-2
driver_opts:
foo: "1"
bar: "2"
[/bash]
おわりに
今回は主にDockerイメージの管理について学びました。Udemyの本講座はまだまだつづきますが、キリが良いので今回のレポートはここまでとさせて頂きます。
リンクバルでは エンジニアを積極募集中 です。興味のある方のご応募お待ちしております。
