4.Networking.md

Networking

Create a Docker bridge network for a developer to use for their containers

• docker network create --driver bridge my-bridge-net
• docker run -d --network my-bridge-net nginx

Troubleshoot container and engine logs to understand a connectivity issue between containers

• To view container logs, enter: docker logs CONTAINER
• To view logs for all tasks of a service, execute: docker service logs SERVICE
• To view Docker daemon logs, input: sudo jounralctl -u docker

Publish a port so that an application is accessible externally

The host port is the port that will listen on the host. Requests to that port on the host will be forwarded to the CONTAINER_PORT inside the container docker run -d -p HOST_PORT:CONTAINER_PORT IMAGE

Identify which IP and port a container is externally accessible on

Describe the different types and use cases for the built-in network drivers

Host This driver connects the container directly to the host’s networking stack. It provides no isolation between containers or between containers and the host. docker run --net host nginx

Bridge This driver uses virtual bridge interfaces to establish connections between containers running on the same host. docker network create --driver bridge my-bridge-net docker run -d --network my-bridge-net nginx

Overlay This driver uses a routing mesh to connect containers across multiple Docker hosts, usually in a Docker swarm docker network create --driver overlay my-overlay-net docker service create --network my-overlay-net nginx

MACVLAN This driver connect containers directly to the host’s network interfaces, but uses special configuration to provide isolation.

docker network create -d macvlan --subnet 192.168.0.0/24 --gateway 192.168.0.1 -o parent=eth0 \ my-macvlan-net docker run -d --net my-macvlan-net nginx

None This driver provides sandbox isolation, but it does not provide any implementation for networking between containers or between containers and the host. docker run --net none -d nginx

Understand the Container Network Model and how it interfaces with the Docker engine and network and IPAM drivers

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Configure Docker to use external DNS

Use Docker to load balance HTTP/HTTPs traffic to an application (Configure L7 load balancing with Docker EE)

Understand and describe the types of traffic that flow between the Docker engine, registry, and UCP controllers

Deploy a service on a Docker overlay network

Describe the difference between "host" and "ingress" port publishing mode