Networking features in Docker Desktop for Mac
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Docker Desktop for Mac provides several networking features to make it easier to use.
Docker Desktop for Mac’s networking can work when attached to a VPN. To do this, Docker Desktop for Mac intercepts traffic from the containers and injects it into Mac as if it originated from the Docker application.
When you run a container with the
-p argument, for example:
$ docker run -p 80:80 -d nginx
Docker Desktop for Mac makes whatever is running on port 80 in the container (in
nginx) available on port 80 of
localhost. In this example, the
host and container ports are the same. What if you need to specify a different
host port? If, for example, you already have something running on port 80 of
your host machine, you can connect the container to a different port:
$ docker run -p 8000:80 -d nginx
Now, connections to
localhost:8000 are sent to port 80 in the container. The
HTTP/HTTPS Proxy Support
SSH agent forwarding
Docker Desktop for Mac allows you to use the host’s SSH agent inside a container. To do this:
Bind mount the SSH agent socket by adding the following parameter to your
SSH_AUTH_SOCKenvironment variable in your container:
To enable the SSH agent in Docker Compose, add the following flags to your service:
services: web: image: nginx:alpine volumes: - type: bind source: /run/host-services/ssh-auth.sock target: /run/host-services/ssh-auth.sock environment: - SSH_AUTH_SOCK=/run/host-services/ssh-auth.sock
Known limitations, use cases, and workarounds
Following is a summary of current limitations on the Docker Desktop for Mac networking stack, along with some ideas for workarounds.
Changing internal IP addresses
The internal IP addresses used by Docker can be changed via the Settings (Windows) or Preferences (Mac). After changing IPs, it is necessary to reset the Kubernetes cluster and to leave any active Swarm.
There is no docker0 bridge on macOS
Because of the way networking is implemented in Docker Desktop for Mac, you cannot see a
docker0 interface on the host. This interface is actually within the virtual
I cannot ping my containers
Docker Desktop for Mac can’t route traffic to containers.
Per-container IP addressing is not possible
The docker (Linux) bridge network is not reachable from the macOS host.
Use cases and workarounds
There are two scenarios that the above limitations affect:
I want to connect from a container to a service on the host
The host has a changing IP address (or none if you have no network access). We recommend that you connect to the special DNS name
host.docker.internal which resolves to the internal IP address used by the
host. This is for development purpose and will not work in a production environment outside of Docker Desktop for Mac.
You can also reach the gateway using
If you have installed Python on your machine, use the following instructions as an example to connect from a container to a service on the host:
Run the following command to start a simple HTTP server on port 8000.
python -m http.server 8000
If you have installed Python 2.x, run
python -m SimpleHTTPServer 8000.
Now, run a container, install
curl, and try to connect to the host using the following commands:
$ docker run --rm -it alpine sh # apk add curl # curl http://host.docker.internal:8000 # exit
I want to connect to a container from the Mac
Port forwarding works for
-P all work.
Ports exposed from Linux are forwarded to the host.
Our current recommendation is to publish a port, or to connect from another container. This is what you need to do even on Linux if the container is on an overlay network, not a bridge network, as these are not routed.
For example, to run an
$ docker run -d -p 80:80 --name webserver nginx
To clarify the syntax, the following two commands both expose port
80 on the
container to port
8000 on the host:
$ docker run --publish 8000:80 --name webserver nginx $ docker run -p 8000:80 --name webserver nginx
To expose all ports, use the
-P flag. For example, the following command
starts a container (in detached mode) and the
-P exposes all ports on the
container to random ports on the host.
$ docker run -d -P --name webserver nginx
See the run command for more details on
publish options used with