Docker Overlay 部署条件
要想使用Docker原生Overlay网络，需要满足以下任意条件：
1、Docker运行在Swarm模式
2、使用键值存储的Docker主机集群
本次部署使用键值存储的Docker主机集群，需要满足以下条件：
1. 集群中主机连接到键值存储，Docker支持Consul、Etcd和Zookeeper；
2. 集群中主机运行一个Docker守护进程；
3. 集群中主机必须具有唯一的主机名，因为键值存储使用主机名来标识集群成员；
4. 集群中Linux主机内核版本3.12+，支持VXLAN数据包处理，否则可能无法通信。
5. Docker通过overlay网络驱动程序支持多主机容器网络通信。
内核版本升级方案：https://www.cnblogs.com/xiangsikai/p/9899844.html
Docker Overlay 应用部署
- 节点1/键值存储：192.168.1.77
- 节点2：192.168.1.78
节点1节点2操作
# 修改两个测试端主机名，并退出终端生效 hostname overlay-01 hostname overlay-02
一、部署Consul并运行服务
1.1 节点1操作：下载Consul二进制包并启动
- 百度云：https://pan.baidu.com/s/1MsVJtYUDJ8LzBqVxwmdc8A
- 密码：g5jd
- 命令行下载：wget https://releases.hashicorp.com/consul/0.9.2/consul_0.9.2_linux_amd64.zip
# 1、解压Consul压缩包 unzip consul_0.9.2_linux_amd64.zip # 2、将consul移动到/bin/目录下并添加执行权限 mv consul /usr/bin/consul && chmod +x /usr/bin/consul # 3、启动consul并指定本机IP nohup consul agent -server -bootstrap -ui -data-dir /var/lib/consul -client=192.168.1.77 -bind=192.168.1.77 &>/var/log/consul.log &
1.2 节点1操作：查看日志启动情况
tail /var/log/consul.log -f
2018/10/29 15:17:39 [INFO] agent: Started HTTP server on 192.168.1.77:8500 2018/10/29 15:17:45 [WARN] raft: Heartbeat timeout from "" reached, starting election 2018/10/29 15:17:45 [INFO] raft: Node at 192.168.1.77:8300 [Candidate] entering Candidate state in term 2 2018/10/29 15:17:45 [INFO] raft: Election won. Tally: 1 2018/10/29 15:17:45 [INFO] raft: Node at 192.168.1.77:8300 [Leader] entering Leader state 2018/10/29 15:17:45 [INFO] consul: cluster leadership acquired 2018/10/29 15:17:45 [INFO] consul: New leader elected: localhost.localdomain 2018/10/29 15:17:45 [INFO] consul: member 'localhost.localdomain' joined, marking health alive 2018/10/29 15:17:45 [INFO] agent: Synced node info ==> Newer Consul version available: 1.3.0 (currently running: 0.9.2)
二、部署Docker配置文件
2.1 节点1操作：配置Docker守护进程连接Consul
# 添加ExecStart如果已有则注释添加下面案例
vim /lib/systemd/system/docker.service
[Service]
ExecStart=/usr/bin/dockerd-current -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --cluster-store consul://192.168.1.77:8500 --cluster-advertise 192.168.1.77:2375
# 为docker监听 tcp://0.0.0.0:2375
2.2 节点1操作：重启docker服务
# 1.修改配置文件重新加载 systemctl daemon-reload # 2.重启docker服务 systemctl restart docker
2.3 节点2操作：修改配置文件
vim /lib/systemd/system/docker.service
[Service]
ExecStart=/usr/bin/dockerd-current -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --cluster-store consul://192.168.1.77:8500 --cluster-advertise 192.168.1.78:2375
# 通告信息需要改为本机IP --cluster-advertise 192.168.1.78:2375
2.4 节点2操作：重启docker服务
# 1.修改配置文件重新加载 systemctl daemon-reload # 2.重启docker服务 systemctl restart docker
三、创建Overlay网络
3.1 节点1操作：创建overlay网络
# 创建网络 -d 指定网络驱动程序为 overlay multi_host docker network create -d overlay multi_host
注：再任意节点创建后会通过overlay同步到已连接的节点下创建网络。
命令：docker network ls 4abe591cdf50 multi_host overlay global
命令：docker network inspect ID/KEY [ { "Name": "multi_host", "Id": "4abe591cdf504c1f15f563e4c8516c22b7d037268e6975e9491a417d2da83e8a", "Created": "2018-11-01T10:42:00.117452769+08:00", "Scope": "global", # 驱动为overlay "Driver": "overlay", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": {}, # 网段信息 "Config": [ { "Subnet": "10.0.0.0/24", "Gateway": "10.0.0.1" } ] }, "Internal": false, "Attachable": false, "Containers": {}, "Options": {}, "Labels": {} } ]
四、测试通信
4.1 节点1与2操作：运行测试容器
# 指定连接网络类型 --net=multi_host docker run -it --net=multi_host busybox
注：如果报错则可在配置文件中ExecStart添加加如下参数
--default-runtime=docker-runc
建议添加 多个参数 --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current --default-runtime=docker-runc --exec-opt native.cgroupdriver=systemd --userland-proxy-path=/usr/libexec/docker/docker-proxy-current --init-path=/usr/libexec/docker/docker-init-current --seccomp-profile=/etc/docker/seccomp.json 如下 ExecStart=/usr/bin/dockerd-current -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --cluster-store consul://192.168.1.77:8500 --cluster-advertise 192.168.1.78:2375 --add-runtime docker-runc=/usr/libexec/docker/docker-runc-current --default-runtime=docker-runc --exec-opt native.cgroupdriver=systemd --userland-proxy-path=/usr/libexec/docker/docker-proxy-current --init-path=/usr/libexec/docker/docker-init-current --seccomp-profile=/etc/docker/seccomp.json
4.2 节点1与2操作：测试通信
overlay-01
/ # ifconfig eth0 Link encap:Ethernet HWaddr 02:42:0A:00:00:03 inet addr:10.0.0.3 Bcast:0.0.0.0 Mask:255.255.255.0 inet6 addr: fe80::42:aff:fe00:3/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1450 Metric:1 RX packets:11 errors:0 dropped:0 overruns:0 frame:0 TX packets:7 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:906 (906.0 B) TX bytes:586 (586.0 B)
overlay-02
/ # ifconfig eth0 Link encap:Ethernet HWaddr 02:42:0A:00:00:02 inet addr:10.0.0.2 Bcast:0.0.0.0 Mask:255.255.255.0 inet6 addr: fe80::42:aff:fe00:2/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1450 Metric:1 RX packets:14 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:1136 (1.1 KiB) TX bytes:656 (656.0 B)
测试是否通信 overlay-02 ping overlay-01
/ # ping 10.0.0.3 PING 10.0.0.3 (10.0.0.3): 56 data bytes 64 bytes from 10.0.0.3: seq=0 ttl=64 time=0.960 ms 64 bytes from 10.0.0.3: seq=1 ttl=64 time=0.355 m
注：通信成功。