Docker容器访问父服务器中的localhost

Question

I've little problem with my docker container. I'm trying to get access by curl from container to my parent server localhost in order to execute query in elasticsearch. Elastic is working only local area on parent server.

curl http://127.0.0.1:9200
curl: (7) Failed to connect to 127.0.0.1 port 9200: Connection refused

The containers ip is 172.17.0.3 and Im able to ping container from parent server

Its my docker build

cd ./api_docker
    container="$(docker ps | grep "visitors/api:gniewoy" | cut -d " " -f1)"
    git reset --hard HEAD &&
    git pull &&
    composer update &&
    docker build -t visitors/api:gniewoy . &&
    cd ../
    docker kill $container &&
    docker run -p 705:80  --env-file docker_api_env -d /etc/docker/

After built the continer is working fine on port 705, but is only the elastic issue. Below are deatils my conainer

"NetworkSettings": {
            "Bridge": "",
            "SandboxID": "",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {
                "443/tcp": null,
                "80/tcp": [
                    {
                        "HostIp": "0.0.0.0",
                        "HostPort": "705"
                    }
                ]
            },
            "SandboxKey": "",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "",
            "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.3",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "",
                    "EndpointID": "",
                    "Gateway": "172.17.0.1",
                    "IPAddress": "172.17.0.3",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": ""
                }
            }
        }

Im working od Debian 8. Thank you

Answer 1

You need to share the port by -p tag something like -p 9200:9200

Here the first 9200 is internal port and the second one is container port.

Take a look at this

Answer 2

The only way to reach loopback on the host machine is to be on it's same loopback network. By default docker will run your container in its own isolated networking namespace, which includes its own separate loopback interface. To run with the host machine's loopback (and the rest of the host machine's networking stack), you would call:

docker run --net host ...

With docker-compose.yml, you would include the following section on the relevant service:

network_mode: "host"

If you can configure your elastic server to listen on all interfaces, that would be better from the container side (though this may introduce other security issues). You would then, from the container, connect to a non-loopback ip on the host.

Answer 3

Your configuration need to be /etc/elasticsearch/elasticsearch.yml

network :
    host : 127.0.0.1  //or ifconfig (ex eth0 : IP)