You can't ping or access a container interface directly with Docker for Mac.
The current best solution is to connect to your containers from
another container. At present there is no way we can provide routing
to these containers due to issues with OSX that Apple have not yet
resolved. we are tracking this requirement, but we cannot do anything
about it at present.
Docker Toolbox/VirtualBox
When running Docker Toolbox, Docker Machine via VirtualBox or any VirtualBox VM (like a Vagrant definition) you can setup a "Host-Only Network" and access the Docker VMs network via that.
If you are using the default boot2docker VM, don't change the existing interface as you will stop a whole lot of Docker utilities from working, add a new interface.
You will also need to setup routing from your Mac to the container networks via your VM's new IP address. In my case the Docker network range is 172.22.0.0/16 and the Host Only adapter IP on the VM is 192.168.99.100.
sudo route add 172.22.0.0/16 192.168.99.100
Adding a permanent route to osx is bit more complex
Then you can get to containers from your Mac
machost:~ ping -c 1 172.22.0.2
PING 172.22.0.2 (172.22.0.2): 56 data bytes
64 bytes from 172.22.0.2: icmp_seq=0 ttl=63 time=0.364 ms
--- 172.22.0.2 ping statistics ---
1 packets transmitted, 1 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.364/0.364/0.364/0.000 ms
Vagrant + Ansible setup
Here's my running config...
Vagrant.configure("2") do |config|
config.vm.box = "debian/contrib-buster64"
config.vm.hostname = "docker"
config.vm.network "private_network", ip: "10.7.7.7", hostname: true
config.vm.provider "virtualbox" do |vb|
vb.gui = false
vb.memory = "4000"
vb.cpus = "4"
end
config.vm.provision "ansible" do |ansible|
ansible.verbose = "v"
ansible.playbook = "tasks.yaml"
end
end
The ansible tasks.yaml to configure a fixed network.
- hosts: all
become: yes
vars:
ansible_python_interpreter: auto_silent
docker_config:
bip: 10.7.2.1/23
host: ["tcp://10.7.7.7:2375"]
userland-proxy: false
tasks:
- ansible.builtin.apt:
update_cache: yes
force_apt_get: yes
pkg:
- bridge-utils
- docker.io
- python3-docker
- python-docker
- iptables-persistent
- ansible.builtin.hostname:
name: docker
- ansible.builtin.copy:
content: "{{ docker_config | to_json }}"
dest: /etc/docker/daemon.json
- ansible.builtin.lineinfile:
line: 'DOCKER_OPTS="{% for host in docker_config.host %} -H {{ host }} {% endfor %}"'
regexp: '^DOCKER_OPTS='
path: /etc/default/docker
- ansible.builtin.systemd:
name: docker.service
state: restarted
- ansible.builtin.iptables:
action: insert
chain: DOCKER-USER
destination: 10.7.2.0/23
in_interface: eth1
out_interface: docker0
jump: ACCEPT
- ansible.builtin.shell: iptables-save > /etc/iptables/rules.v4
Add the route for the docker bridge network via the VM to the mac
$ sudo /sbin/route -n -v add -net 10.7.2.0/23 10.7.7.7
Then set DOCKER_HOST=10.7.7.7 in the environment to use the new VM.
$ export DOCKER_HOST=10.7.7.7
$ docker run --name route_test --rm -d node:14-slim node -e "require('http').createServer((req, res) => {
res.writeHead(200, {'Content-Type':'text/plain'})
res.end('hello')
}).listen(3000)"
$ docker container inspect route_test -f '{{ .NetworkSettings.Networks.bridge.IPAddress }}'
$ curl http://10.7.2.3:3000
hello
$ docker rm -f route_test
You don't get volumes mapped from the host to the vm, but as a bonus it uses a lot less cpu than the Docker 2.5.x release.
