Docker For Mac Network_mode Host
Unfortunately Docker for Desktop doesn't currently support the 'host' networkmode where containers are able to freely bind host ports without being managed by docker. Instead, ports must be explicitly whitelisted in the docker run or the docker-compose.yml. I notice that you have white-listed port 5432 in your docker-compose.yml. Other in the default network using the following docker-compose file: version. If we add networkmode: 'host' to the service it is unable to connect to. So the original problem you are trying to solve is how to get the MAC.
In addition to leveraging the default 'nat' network created by Docker on Windows, users can define custom container networks. User-defined networks can be created using the Docker CLI docker network create -d <NETWORK DRIVER TYPE> <NAME> command. On Windows, the following network driver types are available:
nat – containers attached to a network created with the 'nat' driver will be connected to an internal Hyper-V switch and receive an IP address from the user-specified (
--subnet) IP prefix. Port forwarding / mapping from the container host to container endpoints is supported.Note
NAT networks created on Windows Server 2019 (or above) are no longer persisted after reboot.
Multiple NAT networks are supported if you have the Windows 10 Creators Update installed (or above).
transparent – containers attached to a network created with the 'transparent' driver will be directly connected to the physical network through an external Hyper-V switch. IPs from the physical network can be assigned statically (requires user-specified
--subnetoption) or dynamically using an external DHCP server.Note
Due to the following requirement, connecting your container hosts over a transparent network is not supported on Azure VMs.
Android emulator crashing on Mac. Ask Question Asked 7 years ago. Active 7 months ago. Viewed 16k times 37. When I try to launch Android emulator, it crashes on Mac OS X. It was working some time ago, but now it isn't and I don't have an idea why. Crash log: http. Android studio emulator crashes mac. Android Studio Crashing during AVD Creation Process on Mac OS X. Hello:) Right now, I am learning Android Development in Treehouse (which rocks by the way!), and I seem to have run into a roadblock. This is a problem with either Android Studio or my Mac (which is an Early 2008 MacBook running Lion.I need to get a newer Mac I know:p), but I.
Requires: When this mode is used in a virtualization scenario (container host is a VM) MAC address spoofing is required.
overlay - when the docker engine is running in swarm mode, containers attached to an overlay network can communicate with other containers attached to the same network across multiple container hosts. Each overlay network that is created on a Swarm cluster is created with its own IP subnet, defined by a private IP prefix. The overlay network driver uses VXLAN encapsulation. Can be used with Kubernetes when using suitable network control planes (e.g. Flannel).
Requires: Make sure your environment satisfies these required prerequisites for creating overlay networks.
Requires: On Windows Server 2019, this requires KB4489899.
Requires: On Windows Server 2016, this requires KB4015217.
Note
On Windows Server 2019, overlay networks created by Docker Swarm leverage VFP NAT rules for outbound connectivity. This means that a given container receives 1 IP address. It also means that ICMP-based tools such as
pingorTest-NetConnectionshould be configured using their TCP/UDP options in debugging situations.l2bridge - similar to
transparentnetworking mode, containers attached to a network created with the 'l2bridge' driver will be connected to the physical network through an external Hyper-V switch. The difference in l2bridge is that container endpoints will have the same MAC address as the host due to Layer-2 address translation (MAC re-write) operation on ingress and egress. In clustering scenarios, this helps alleviate the stress on switches having to learn MAC addresses of sometimes short-lived containers. L2bridge networks can be configured in 2 different ways:- L2bridge network is configured with the same IP subnet as the container host
- L2bridge network is configured with a new custom IP subnet
In configuration 2 users will need to add a endpoint on the host network compartment that acts as a gateway and configure routing capabilities for the designated prefix.
Requires: Requires Windows Server 2016, Windows 10 Creators Update, or a later release.
l2bridge - similar to
transparentnetworking mode, containers attached to a network created with the 'l2bridge' driver will be connected to the physical network through an external Hyper-V switch. The difference in l2bridge is that container endpoints will have the same MAC address as the host due to Layer-2 address translation (MAC re-write) operation on ingress and egress. In clustering scenarios, this helps alleviate the stress on switches having to learn MAC addresses of sometimes short-lived containers. L2bridge networks can be configured in 2 different ways:- L2bridge network is configured with the same IP subnet as the container host
- L2bridge network is configured with a new custom IP subnet
In configuration 2 users will need to add a endpoint on the host network compartment that acts as a gateway and configure routing capabilities for the designated prefix.
Tip
More details on how to configure and install l2bridge can be found here.
l2tunnel - Similar to l2bridge, however this driver should only be used in a Microsoft Cloud Stack (Azure). Packets coming from a container are sent to the virtualization host where SDN policy is applied.
Network topologies and IPAM
The table below shows how network connectivity is provided for internal (container-to-container) and external connections for each network driver.
Networking modes/Docker drivers
| Docker Windows Network Driver | Typical uses | Container-to-container (Single node) | Container-to-external (single node + multi-node) | Container-to-container (multi-node) |
|---|---|---|---|---|
| NAT (Default) | Good for Developers |
| Routed through Management vNIC (bound to WinNAT) | Not directly supported: requires exposing ports through host |
| Transparent | Good for Developers or small deployments |
| Routed through container host with direct access to (physical) network adapter | Routed through container host with direct access to (physical) network adapter |
| Overlay | Good for multi-node; required for Docker Swarm, available in Kubernetes |
| Not directly supported - requires second container endpoint attached to NAT network on Windows Server 2016 or VFP NAT rule on Windows Server 2019. | Same/Cross Subnet: Network traffic is encapsulated using VXLAN and routed through Mgmt vNIC |
| L2Bridge | Used for Kubernetes and Microsoft SDN |
| Container MAC address re-written on ingress and egress |
|
| L2Tunnel | Azure only | Same/Cross Subnet: Hair-pinned to physical host's Hyper-V virtual switch to where policy is applied | Traffic must go through Azure virtual network gateway | Same/Cross Subnet: Hair-pinned to physical host's Hyper-V virtual switch to where policy is applied |
IPAM
IP Addresses are allocated and assigned differently for each networking driver. Windows uses the Host Networking Service (HNS) to provide IPAM for the nat driver and works with Docker Swarm Mode (internal KVS) to provide IPAM for overlay. All other network drivers use an external IPAM.
| Networking Mode / Driver | IPAM |
|---|---|
| NAT | Dynamic IP allocation and assignment by Host Networking Service (HNS) from internal NAT subnet prefix |
| Transparent | Static or dynamic (using external DHCP server) IP allocation and assignment from IP addresses within container host's network prefix |
| Overlay | Dynamic IP allocation from Docker Engine Swarm Mode managed prefixes and assignment through HNS |
| L2Bridge | Static IP allocation and assignment from IP addresses within container host's network prefix (could also be assigned through HNS) |
| L2Tunnel | Azure only - Dynamic IP allocation and assignment from plugin |
Service Discovery
Service Discovery is only supported for certain Windows network drivers.
| Local Service Discovery | Global Service Discovery | |
|---|---|---|
| nat | YES | YES with Docker EE |
| overlay | YES | YES with Docker EE or kube-dns |
| transparent | NO | NO |
| l2bridge | NO | YES with kube-dns |
Docker Desktop for Mac provides several networking features to make iteasier to use.
Features
VPN Passthrough
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 intoMac as if it originated from the Docker application.
Port Mapping
When you run a container with the -p argument, for example:
Docker Desktop for Mac makes whatever is running on port 80 in the container (inthis case, nginx) available on port 80 of localhost. In this example, thehost and container ports are the same. What if you need to specify a differenthost port? If, for example, you already have something running on port 80 ofyour host machine, you can connect the container to a different port:
Now, connections to localhost:8000 are sent to port 80 in the container. Thesyntax for -p is HOST_PORT:CLIENT_PORT.
HTTP/HTTPS Proxy Support
See Proxies.
Known limitations, use cases, and workarounds
Following is a summary of current limitations on the Docker Desktop for Macnetworking stack, along with some ideas for workarounds.
There is no docker0 bridge on macOS
Because of the way networking is implemented in Docker Desktop for Mac, you cannot see adocker0 interface on the host. This interface is actually within the virtualmachine.
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). From18.03 onwards our recommendation is to connect to the special DNS namehost.docker.internal, which resolves to the internal IP address used by thehost.This is for development purpose and will not work in a production environment outside of Docker Desktop for Mac.
The gateway is also reachable as gateway.docker.internal.
I want to connect to a container from the Mac
Port forwarding works for localhost; --publish, -p, or -P all work.Ports exposed from Linux are forwarded to the host.
Our current recommendation is to publish a port, or to connect from anothercontainer. This is what you need to do even on Linux if the container is on anoverlay network, not a bridge network, as these are not routed.
The command to run the nginx webserver shown in Getting Startedis an example of this.
To clarify the syntax, the following two commands both expose port 80 on thecontainer to port 8000 on the host:
To expose all ports, use the -P flag. For example, the following commandstarts a container (in detached mode) and the -P exposes all ports on thecontainer to random ports on the host.
See the run command for more details onpublish options used with docker run.