Container to container communication in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is container to container communication in Docker?

It is the process where two or more Docker containers exchange data or messages directly with each other.

beginner

How do Docker containers communicate by default when on the same user-defined network?

They can communicate using container names as hostnames because Docker's user-defined networks provide automatic DNS resolution.

beginner

What Docker command creates a user-defined network for container communication?

docker network create my-network

intermediate

Why is it recommended to use user-defined bridge networks for container communication instead of the default bridge network?

User-defined bridge networks provide better isolation, automatic DNS resolution, and easier container name communication compared to the default bridge network.

intermediate

How can you allow two containers to communicate if they are on different Docker networks?

You can connect a container to multiple networks using 'docker network connect' or create a shared network both containers join.

Which Docker network type allows containers to communicate using container names as hostnames?

A None network

B Host network

C Default bridge network

D User-defined bridge network

User-defined bridge networks provide automatic DNS resolution, allowing containers to use container names to communicate.

What command creates a new Docker network named 'app-net'?

A docker create network app-net

B docker network create app-net

C docker network new app-net

D docker create app-net network

The correct syntax to create a network is 'docker network create '.

If two containers are on the default bridge network, how do they communicate?

A Using IP addresses only

B Using container names as hostnames

C They cannot communicate

D Using host machine's IP

On the default bridge network, containers must use IP addresses to communicate because DNS resolution is not provided.

How can you connect an existing container to a new network?

A docker network connect <network> <container>

B docker connect network <container>

C docker network add <container> <network>

D docker container network connect <container> <network>

The command 'docker network connect ' connects a container to a network.

What is a benefit of using user-defined networks for container communication?

A No network isolation

B Containers cannot communicate

C Automatic DNS resolution

D Slower communication

User-defined networks provide automatic DNS resolution, making container communication easier.

Explain how Docker containers communicate when placed on the same user-defined network.

Think about how computers find each other on a network using names.

Describe the steps to enable communication between two containers on different Docker networks.

Consider how you would connect two groups of friends who are in different rooms.