使用同一网络的多个项目的Docker DNS
我有以下 docker-compose.yml
文件:
version: '3'
services:
frontend:
image: alpine
command: tail -f /dev/null
networks:
- shared
- default
backend:
image: alpine
command: tail -f /dev/null
networks:
- shared
- default
networks:
shared:
external: true
基于从上面的文件中,我创建了两个使用相同网络(共享
)和相同服务名称( frontend
)的项目, 后端
):
Based on the file from above I create two projects which use the same network (shared
) and the same service names (frontend
and backend
):
docker-compose -p foo up -d
docker-compose -p bar up -d
docker的DNS是否确保 docker-compose -p foo exec前端ping后端
仅解析为项目 foo
中的后端容器反之亦然,对于项目 bar
?
Does the DNS of docker make sure that docker-compose -p foo exec frontend ping backend
only resolves to the backend container in project foo
and vice versa for project bar
?
根据 https://github.com/docker/compose/issues/4645 ,其中的解析顺序不确定的情况。由于网络正在使用golang转换为无序dict,因此不会保留顺序。这意味着 https://github.com/docker/libnetwork/blob/ master / sandbox.go#L593 被查询的端点顺序与网络顺序不匹配。
According to https://github.com/docker/compose/issues/4645, the resolve order in this case in non deterministic. Since the network is being converted to unordered dict in golang, the order is not preserved. Which implies https://github.com/docker/libnetwork/blob/master/sandbox.go#L593 the order of endpoints being queried don't match the order of network.
解决方案是定义如果使用docker-compose版本2,则https://docs.docker.com/compose/compose-file/compose-file-v2/#priority ,或者将标准dns名称作为 service.network
,例如 backend.foo_default
或 backend.shared
The solution is to define https://docs.docker.com/compose/compose-file/compose-file-v2/#priority if using docker-compose version 2. Or fully qualified dns name as service.network
such as backend.foo_default
or backend.shared
.