Docker 1.10通过主机从主机访问容器 [英] Docker 1.10 access a container by it's hostname from a host machine

问题描述

我的Docker版本1.10具有嵌入式DNS服务。

我已经在docker-compose文件中创建了两个服务容器。它们可以通过主机名和IP来相互访问，但是当我想要从主机访问其中的一个时，它不起作用，它只适用于IP而不是主机名。

那么，是否可以通过Docker 1.10的主机名从主机访问Docker容器？

更新：

docker-compose.yml

 版本：'2'
服务：
 service_a：
 image：nginx 
 container_name：docker_a 
 ports：
  -  8080 ：80 
 service_b：
 image：nginx 
 container_name：docker_b 
 ports：
  -  8081：80 
  

然后我通过命令启动它： docker-compos up --force-recreate

当我运行：

• docker exec -i -t docker_a ping - c4 docker_b - 它的工作原理


• docker exec -i -t docker_b ping -c4 docker_a - 它的工作原理


• ping 172.19.0.2 - 它有效（ 172.19.0.2 code> docker_b 的ip）


• ping docker _a - 失败

docker网络检查test_default 是

  [
 {
名称： test_default，
Id：f6436ef4a2cd4c09ffdee82b0d0b47f96dd5aee3e1bde068376dd26f81e79712，
Scope：local，
Driver：bridge，
IPAM b $ bDriver：default，
Options：null，
Config：[
 {
Subnet：172.19.0.0/16 ，
网关：172.19.0.1/16
} 
] 
}，
容器：{
a9f13f023761123115fcb2b454d3fd21666b8e1e0637f134026c44a7a84f1b0b 
Name：docker_a，
EndpointID：a5c8e08feda96d0de8f7c6203f2707dd3f9f6c3a64666126055b16a3908fafed，
MacAddress：02：42：ac：13：00：03，
IPv4Address：172.19.0.3/16，
IPv6Address：
}，
c6532af99f691659b452c1cbf1693731a75cdfab9ea50428d9c99dd09c3e9a40：{
Name：docker_b，
EndpointID：28a1877a0fdbaeb8d33a290e5a5768edc737d069d23ef9bbcc1d64cfe5fbe312，
MacAddress：02：42：ac：13：00：02，
IPv4Address：172.19.0.2/16 b $ bIPv6Address：
} 
}，
选项：{} 
} 
] 
  

解决方案

这是我做的。

写了一个名为 dnsthing 的Python脚本，该脚本侦听Docker事件API，以启动或停止容器。它使用容器的名称和地址维护一个主机 -style文件。容器被命名为< container_name>。< network> .docker ，所以例如如果我运行：

  docker run --rm --name mysql -e MYSQL_ROOT_PASSWORD = secret mysql 
  

我得到这个：

  172.17.0.2 mysql.bridge.docker 
  

然后，我运行一个 dnsmasq 进程指向这个 code>文件。具体来说，我使用以下配置运行一个dnsmasq实例：

  listen-address = 172.31.255.253 
 bind-interfaces 
 addn-hosts = / run / dnsmasq / docker.hosts 
 local = / docker / 
无主机
无解决方案
  

我运行 dnsthing 脚本，如下所示：

  dnsthing -csystemctl restart dnsmasq_docker\ 
 -H /run/dnsmasq/docker.hosts --verbose 
  

所以：

• dnsthing 更新 /run/dnsmasq/docker.hosts 作为容器
  停止/开始


• 更新后， dnsthing 运行 systemctl restart dnsmasq_docker


• dnsmasq_docker 使用上述配置运行 dnsmasq ，将
  绑定到本地网桥接口，地址为 172.31 .255.253 。



• 我的系统上的主dnsmasq进程由
  维护NetworkMana ger，从
  /etc/NetworkManager/dnsmasq.d/dockerdns 中使用此配置：

    server = / docker / 172.31.255.253 
    

  告诉dnsmasq通过 .docker
  中的主机所有请求到 docker_dnsmasq 服务。

这显然需要一些设置把所有东西放在一起，但是
之后似乎Just Work：

  $ ping -c1 mysql.bridge.docker 
 PING mysql.bridge.docker（172.17.0.2）56（84）个字节数据。 
从172.17.0.2的64字节：icmp_seq = 1 ttl = 64时间= 0.087毫秒
 
 --- mysql.bridge.docker ping统计--- 
 1个数据包传输， 1收到，0％丢包，时间0ms 
 rtt最小/ avg / max / mdev = 0.087 / 0.087 / 0.087 / 0.000 ms 
  

I have the Docker version 1.10 with embedded DNS service.

I have created two service containers in my docker-compose file. They are reachable each other by hostname and by IP, but when I would like reach one of them from the host machine, it doesn't work, it works only with IP but not with hostname.

So, is it possible to access a docker container from the host machine by it's hostname in the Docker 1.10, please?

Update:

docker-compose.yml

version: '2'
services:
    service_a:
        image: nginx
        container_name: docker_a
        ports:
           - 8080:80
    service_b:
        image: nginx
        container_name: docker_b
        ports:
            - 8081:80

then I start it by command: docker-compose up --force-recreate

when I run:

• docker exec -i -t docker_a ping -c4 docker_b - it works
• docker exec -i -t docker_b ping -c4 docker_a - it works
• ping 172.19.0.2 - it works (172.19.0.2 is docker_b's ip)
• ping docker_a - fails

The result of the docker network inspect test_default is

[
    {
        "Name": "test_default",
        "Id":   "f6436ef4a2cd4c09ffdee82b0d0b47f96dd5aee3e1bde068376dd26f81e79712",
        "Scope": "local",
        "Driver": "bridge",
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "172.19.0.0/16",
                    "Gateway": "172.19.0.1/16"
                }
            ]
        },
        "Containers": {
             "a9f13f023761123115fcb2b454d3fd21666b8e1e0637f134026c44a7a84f1b0b": {
                "Name": "docker_a",
                "EndpointID":     "a5c8e08feda96d0de8f7c6203f2707dd3f9f6c3a64666126055b16a3908fafed",
                "MacAddress": "02:42:ac:13:00:03",
                "IPv4Address": "172.19.0.3/16",
                "IPv6Address": ""
            },
                "c6532af99f691659b452c1cbf1693731a75cdfab9ea50428d9c99dd09c3e9a40": {
                "Name": "docker_b",
                "EndpointID":     "28a1877a0fdbaeb8d33a290e5a5768edc737d069d23ef9bbcc1d64cfe5fbe312",
                "MacAddress": "02:42:ac:13:00:02",
                "IPv4Address": "172.19.0.2/16",
                "IPv6Address": ""
            }
        },
        "Options": {}
    }
]

解决方案

Here's what I do.

I wrote a Python script called dnsthing, which listens to the Docker events API for containers starting or stopping. It maintains a hosts-style file with the names and addresses of containers. Containers are named <container_name>.<network>.docker, so for example if I run this:

docker run --rm --name mysql -e MYSQL_ROOT_PASSWORD=secret  mysql

I get this:

172.17.0.2 mysql.bridge.docker

I then run a dnsmasq process pointing at this hosts file. Specifically, I run a dnsmasq instance using the following configuration:

listen-address=172.31.255.253
bind-interfaces
addn-hosts=/run/dnsmasq/docker.hosts
local=/docker/
no-hosts
no-resolv

And I run the dnsthing script like this:

dnsthing -c "systemctl restart dnsmasq_docker" \
  -H /run/dnsmasq/docker.hosts --verbose

So:

• dnsthing updates /run/dnsmasq/docker.hosts as containers stop/start
• After an update, dnsthing runs systemctl restart dnsmasq_docker
• dnsmasq_docker runs dnsmasq using the above configuration, bound to a local bridge interface with the address 172.31.255.253.

• The "main" dnsmasq process on my system, maintained by NetworkManager, uses this configuration from /etc/NetworkManager/dnsmasq.d/dockerdns:

  server=/docker/172.31.255.253
  

  That tells dnsmasq to pass all requests for hosts in the .docker domain to the docker_dnsmasq service.

This obviously requires a bit of setup to put everything together, but after that it seems to Just Work:

$ ping -c1  mysql.bridge.docker
PING mysql.bridge.docker (172.17.0.2) 56(84) bytes of data.
64 bytes from 172.17.0.2: icmp_seq=1 ttl=64 time=0.087 ms

--- mysql.bridge.docker ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.087/0.087/0.087/0.000 ms

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