Docker网络

Docker0

#启动一个tomcat容器
docker run -d -P --name tomcat01 tomcat
#查看容器ip端口	166: eth0@if167
docker exec -it tomcat01 ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
166: eth0@if167: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:12:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.18.0.2/16 brd 172.18.255.255 scope global eth0
       valid_lft forever preferred_lft forever
#测试ping是成功的
ping 172.18.0.2
PING 172.18.0.2 (172.18.0.2) 56(84) bytes of data.
64 bytes from 172.18.0.2: icmp_seq=1 ttl=64 time=0.082 ms
#查看主机地址		167: vethf13c59d@if166
ip addr
...
3: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:fb:7c:e2:90 brd ff:ff:ff:ff:ff:ff
    inet 172.18.0.1/16 brd 172.18.255.255 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:fbff:fe7c:e290/64 scope link 
       valid_lft forever preferred_lft forever
167: vethf13c59d@if166: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 0e:85:67:5d:0c:32 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::c85:67ff:fe5d:c32/64 scope link 
       valid_lft forever preferred_lft forever

我们每启动一个docker容器, docker就会给docker容器分配一个ip, 我们只要安装了docker,就会有一个网卡docker0, 这里使用的是桥接模式, 使用的技术是veth-pair
veth-pair 就是一对的虚拟设备接口，他们都是成对出现的，一段连着协议，一段彼此相连，正因为有这个特性，veth-pair充当一个桥梁，专门连接各种虚拟网络设备

#再启动一个tomcat容器
docker run -d -P --name tomcat02 tomcat
#容器端口	168: eth0@if169
[root@pinked ~]# docker exec -it tomcat02 ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
168: eth0@if169: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:12:00:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.18.0.3/16 brd 172.18.255.255 scope global eth0
       valid_lft forever preferred_lft forever
#查看主机, 又多了一对网卡	169: vethe6f3759@if168
ip addr
...
169: vethe6f3759@if168: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 36:ed:8b:0d:5b:0b brd ff:ff:ff:ff:ff:ff link-netnsid 1
    inet6 fe80::34ed:8bff:fe0d:5b0b/64 scope link 
       valid_lft forever preferred_lft forever
#容器2也可以ping成功docker0的地址
docker exec -it tomcat02 ping 172.18.0.2
PING 172.18.0.2 (172.18.0.2) 56(84) bytes of data.
64 bytes from 172.18.0.2: icmp_seq=1 ttl=64 time=0.107 ms

docker会为容器分配一个默认可用的ip, docker使用的是linux的桥接, 宿主机中是一个docker容器的网桥docker0

--link

在我们关闭掉容器服务后, 再次启动时, 容器的ip可能会发送改变, 能否实现通过容器名来进行连接, 实现高可用呢?

#无法ping成功
docker exec -it tomcat01 ping tomcat02
ping: tomcat02: Name or service not known
#启动一个tomcat03， 通过--link连接到tomcat01
docker run -d -P --name tomcat03 --link tomcat01 tomcat
#此时，tomcat03可以ping成功tomcat01， 但是tomcat01还是不能ping成功tomcat03
docker exec -it tomcat03 ping tomcat01
PING tomcat01 (172.18.0.2) 56(84) bytes of data.
64 bytes from tomcat01 (172.18.0.2): icmp_seq=1 ttl=64 time=0.108 ms
docker exec -it tomcat01 ping tomcat03
ping: tomcat03: Name or service not known
#查看tomcat03的host配置
docker exec -it tomcat03 cat /etc/hosts
127.0.0.1	localhost
::1	localhost ip6-localhost ip6-loopback
fe00::0	ip6-localnet
ff00::0	ip6-mcastprefix
ff02::1	ip6-allnodes
ff02::2	ip6-allrouters
172.18.0.2	tomcat01 4cc818a0f734	#通过ip映射到了tomcat01
172.18.0.4	fa92415db20d

但是现在--link已经不再建议使用了

自定义网络

网络模式

bridge: 桥接docker
none: 不配置网络
host: 和宿主机共享网络
container: 容器网络互通

测试

#创建自定义的网络, 使用桥接模式(默认模式也是桥接), 配置子网掩码， 配置网关
docker network create --driver bridge --subnet 192.168.0.0/16 --gateway 192.168.0.1 mynet
#查看docker网络, 可以看到刚刚自定义的mynet
docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
f46b01d7fce5        bridge              bridge              local
8e84dd9c7ad4        host                host                local
55a13bf2f845        mynet               bridge              local
89a41d0f6030        none                null                local
#新建两个tomcat使用自定义的mynet
docker run -d -P --name tomcat01-mynet --net mynet tomcat
docker run -d -P --name tomcat02-mynet --net mynet tomcat
#查看mynet的信息
docker network inspect mynet
[
    {
        "Name": "mynet",
        "Id": "55a13bf2f845feae2d55fabd0a87332826083aa40400f369062c6e803f824efe",
        "Created": "2020-09-23T18:01:24.780267045+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "192.168.0.0/16",
                    "Gateway": "192.168.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {
            "7caab6f9eab10aa94623d597b22a81045e38ac1c9310c5693f954600f5cb72eb": {
                "Name": "tomcat02-mynet",
                "EndpointID": "32a43dfba813b6ddf32f4debbca88b2f1dab90c136f03173bded884d95c42290",
                "MacAddress": "02:42:c0:a8:00:03",
                "IPv4Address": "192.168.0.3/16",
                "IPv6Address": ""
            },
            "9ad209b09eee8cd6de808635045318b47f0c8d703681fd1c5c789bbbe73c0dd9": {
                "Name": "tomcat01-mynet",
                "EndpointID": "2648125f56886e1018e3575d52d1c9e008dbd4f4bf22d7aca06a3aa15afc18a0",
                "MacAddress": "02:42:c0:a8:00:02",
                "IPv4Address": "192.168.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {},
        "Labels": {}
    }
]
#在自定义的mynet网络中, 容器可以直接通过容器名ping成功
docker exec -it tomcat01-mynet ping tomcat02-mynet 
PING tomcat02-mynet (192.168.0.3) 56(84) bytes of data.
64 bytes from tomcat02-mynet.mynet (192.168.0.3): icmp_seq=1 ttl=64 time=0.077 ms

自定义网络的方式可以帮助我们更好地维护容器对应的关系

网络连通

tomcat01在docker0的网络下, 而tomcat01-mynet在mynet网络下, 如何可以实现tomcat01对tomcat01-mynet的连接呢?

#跨network下并不能ping成功
docker exec -it tomcat01 ping tomcat01-mynet 
ping: tomcat01-mynet: Name or service not known
#连接tomcat01到mynet
docker network connect mynet tomcat01
#查看mynet信息, tomcat01已经被连接到了mynet中
docker network inspect mynet
...
"f48b257d6a25e79d7f9dc83716d1e911ae72a5834e26d23ed8c4cb6f474e5792": {
    "Name": "tomcat01",
    "EndpointID": "e3620d4043efc0dd9b9e5b9548f5614a6aa0dfb5f6e8a22ace986e1009ee10b5",
    "MacAddress": "02:42:c0:a8:00:04",
    "IPv4Address": "192.168.0.4/16",
    "IPv6Address": ""
}
...
#再测试tomcat01对tomcat01-mynet已经可以平成功了
docker exec -it tomcat01 ping tomcat01-mynet 
PING tomcat01-mynet (192.168.0.2) 56(84) bytes of data.
64 bytes from tomcat01-mynet.mynet (192.168.0.2): icmp_seq=1 ttl=64 time=0.088 ms

部署Redis集群

#新建一个redis用的网络
docker network create redis-network --subnet 172.38.0.0/16
#运行命令行脚本
for port in $(seq 1 6); 
do 
mkdir -p /mydata/redis/node-${port}/conf
touch /mydata/redis/node-${port}/conf/redis.conf
cat <<EOF>/mydata/redis/node-${port}/conf/redis.conf
port 6379
bind 0.0.0.0
cluster-enabled yes
cluster-config-file nodes.conf
cluster-node-timeout 5000
cluster-announce-ip 172.38.0.1${port}
cluster-announce-port 6379
cluster-announce-bus-port 16379
appendonly yes
EOF
done
#启动6个redis
docker run -p 6371:6379 -p 16371:16379 --name redis-1 
 -v /mydata/redis/node-1/data:/data 
 -v /mydata/redis/node-1/conf/redis.conf:/etc/redis/redis.conf 
 -d --net redis-network --ip 172.38.0.11 redis:alpine redis-server /etc/redis/redis.conf
docker run -p 6372:6379 -p 16372:16379 --name redis-2 
 -v /mydata/redis/node-2/data:/data 
 -v /mydata/redis/node-2/conf/redis.conf:/etc/redis/redis.conf 
 -d --net redis-network --ip 172.38.0.12 redis:alpine redis-server /etc/redis/redis.conf	
docker run -p 6373:6379 -p 16373:16379 --name redis-3 
 -v /mydata/redis/node-3/data:/data 
 -v /mydata/redis/node-3/conf/redis.conf:/etc/redis/redis.conf 
 -d --net redis-network --ip 172.38.0.13 redis:alpine redis-server /etc/redis/redis.conf
docker run -p 6374:6379 -p 16374:16379 --name redis-4 
 -v /mydata/redis/node-4/data:/data 
 -v /mydata/redis/node-4/conf/redis.conf:/etc/redis/redis.conf 
 -d --net redis-network --ip 172.38.0.14 redis:alpine redis-server /etc/redis/redis.conf
docker run -p 6375:6379 -p 16375:16379 --name redis-5 
 -v /mydata/redis/node-5/data:/data 
 -v /mydata/redis/node-5/conf/redis.conf:/etc/redis/redis.conf 
 -d --net redis-network --ip 172.38.0.15 redis:alpine redis-server /etc/redis/redis.conf
docker run -p 6376:6379 -p 16376:16379 --name redis-6 
 -v /mydata/redis/node-6/data:/data 
 -v /mydata/redis/node-6/conf/redis.conf:/etc/redis/redis.conf 
 -d --net redis-network --ip 172.38.0.16 redis:alpine redis-server /etc/redis/redis.conf
 #进入redis-1 (redis容器下没有bash命令, 需使用sh）
 docker exec -it redis-1 sh
 #建立集群
redis-cli --cluster create 172.38.0.11:6379 172.38.0.12:6379 172.38.0.13:6379 172.38.0.14:6379 172.38.0.15:6379 172.38.0.16:6379 --cluster-replicas 1
#连接集群, 查看信息
/data # redis-cli -c
127.0.0.1:6379> cluster info
cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:6
cluster_size:3
cluster_current_epoch:6
cluster_my_epoch:1
cluster_stats_messages_ping_sent:200
cluster_stats_messages_pong_sent:220
cluster_stats_messages_sent:420
cluster_stats_messages_ping_received:215
cluster_stats_messages_pong_received:200
cluster_stats_messages_meet_received:5
cluster_stats_messages_received:420
#查看节点
127.0.0.1:6379> cluster nodes
365c9d5572f37a736ca9a1b6b9933dfa9258d002 172.38.0.15:6379@16379 slave 54720d691161088372d6e5c4ae7f1192b9be634c 0 1600933795765 1 connected
54720d691161088372d6e5c4ae7f1192b9be634c 172.38.0.11:6379@16379 myself,master - 0 1600933796000 1 connected 0-5460
df5111939002c5572891e097cd53b811bf979231 172.38.0.12:6379@16379 master - 0 1600933796265 2 connected 5461-10922
410eeebae782517cea287d545e1f72e54458afb3 172.38.0.16:6379@16379 slave df5111939002c5572891e097cd53b811bf979231 0 1600933797267 2 connected
a433eff9790cf78a366f1fde4d3c148f7fe9bac6 172.38.0.13:6379@16379 master - 0 1600933795765 3 connected 10923-16383
9b4314e3b3ef9928c126d495f531c04261281d9e 172.38.0.14:6379@16379 slave a433eff9790cf78a366f1fde4d3c148f7fe9bac6 0 1600933797768 3 connected
#存储一个值, 保存在了redis-2上
127.0.0.1:6379> set key1 pinked
-> Redirected to slot [9189] located at 172.38.0.12:6379
OK
#容器外停止redis-2
docker stop redis-2
#容器redis集群中, 因为redis-2停止了, 数据从redis-6中得到
127.0.0.1:6379> get key1
-> Redirected to slot [9189] located at 172.38.0.16:6379
"pinked"
#查看节点, redis-2 fail了, redis-6成为了新的主机
172.38.0.16:6379> cluster nodes
df5111939002c5572891e097cd53b811bf979231 172.38.0.12:6379@16379 master,fail - 1600934055549 1600934053033 2 connected
410eeebae782517cea287d545e1f72e54458afb3 172.38.0.16:6379@16379 myself,master - 0 1600934988000 8 connected 5461-10922
...

打包springboot项目为docker镜像

新建一个springboot项目, 仅保留一个测试请求即可
打包成jar包

新建Dockerfile

FROM java:8

COPY *.jar /app.jar

CMD ["--server.port=8000"]

EXPOSE 8000

ENTRYPOINT ["java","-jar","/app.jar"]

复制Dockerfile文件和jar包到服务器
build镜像
```
docker build -t docker-jar .
```

运行及测试

docker run -d -p 9000:8000 --name jar11  docker-jar
curl localhost:9000