DNS resolution between containers in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is DNS resolution between containers in Docker?

It is the process where containers use container names as hostnames to find and communicate with each other automatically within the same Docker network.

beginner

How does Docker enable DNS resolution between containers?

Docker creates an internal DNS server for each user-defined network. Containers connected to this network can resolve each other's names to IP addresses automatically.

beginner

What command creates a user-defined Docker network for DNS resolution?

docker network create my-network

beginner

How do you connect containers to the same network for DNS resolution?

Use the --network option when running containers, for example: docker run --network my-network --name container1 busybox

intermediate

What happens if containers are on the default bridge network regarding DNS resolution?

Containers on the default bridge network cannot resolve each other by name automatically; you must use IP addresses or create a user-defined network.

Which Docker network type supports automatic DNS resolution between containers?

A Default bridge network

B Host network

C None network

D User-defined bridge network

User-defined bridge networks have an internal DNS server that allows containers to resolve each other's names.

What is the correct command to create a Docker network named 'app-net'?

A docker network create app-net

B docker create network app-net

C docker network new app-net

D docker create app-net network

The correct syntax is 'docker network create '.

How do containers resolve each other's names inside a user-defined network?

A Using external DNS servers

B Using Docker's internal DNS server

C Using hosts file only

D They cannot resolve names automatically

Docker provides an internal DNS server for user-defined networks to resolve container names.

If two containers are on different user-defined networks, can they resolve each other's names?

A Only if they share the same image

B Yes, always

C No, DNS resolution works only within the same network

D Only if they use host networking

DNS resolution between containers works only if they are connected to the same user-defined network.

Which option connects a container to a specific Docker network?

A --network

B --net-connect

C --link

D --connect-network

The '--network' option specifies the network a container should join.

Explain how DNS resolution works between Docker containers on the same user-defined network.

Think about how containers find each other by name inside Docker.

Describe the steps to enable DNS resolution between two Docker containers.

Focus on network creation and container startup options.