This content originally appeared on DEV Community and was authored by Bhaskar Sharma

Hello dev.to community!

Yesterday, I explored Docker Basics — the foundation of containerization. Today, I’m diving into Networking & Volumes in Docker — two essential concepts that bring containers closer to real-world use cases.

Why Networking & Volumes Matter

Networking → lets containers communicate with each other and the outside world.

Volumes → ensure data persists even if containers are removed.

In DevOps, both are crucial for building reliable, production-ready systems.

Core Concepts I’m Learning

Docker Networking

Bridge network (default): containers get private IPs and can talk to each other.

Host network: container shares host’s network.

Overlay network: connects containers across multiple hosts (used in Swarm/K8s).

Example:

Create a custom bridge network

docker network create mynet

Run two containers in the same network

docker run -d –name web –network mynet nginx

docker run -it –network mynet alpine ping web

Docker Volumes

Volumes store data outside container lifecycle.

Great for databases, logs, and config files.

Types: named volumes, host mounts, anonymous volumes.

Example:

Create a volume

docker volume create mydata

Run MySQL with volume

docker run -d -v mydata:/var/lib/mysql mysql

Mini Use Cases in DevOps

Run a database container with volumes to persist data.

Connect backend & frontend containers via networks.

Share config files securely across multiple services.

Pro Tips

Use named volumes instead of host paths for portability.

Inspect networks with:

docker network ls

docker network inspect mynet

Clean up unused volumes & networks:

docker volume prune

docker network prune

Hands-on Mini-Lab (Try this!)

1⃣ Create a network:

docker network create devnet

2⃣ Run Nginx & Redis in the same network:

docker run -d –name mynginx –network devnet nginx

docker run -d –name myredis –network devnet redis

3⃣ Verify connectivity:

docker exec -it mynginx ping myredis

Containers are now talking to each other inside devnet!

Key Takeaway
Networking connects containers like a mini-internet, while volumes ensure data survives beyond container restarts. Together, they make Docker production-grade.

Tomorrow (Day 9)
I’ll dive into Dockerfiles & Image Building — automating app packaging for CI/CD pipelines.

#Docker #Containers #DevOps #CICD #DevOpsJourney #CloudNative #SRE #Automation #OpenSource

This content originally appeared on DEV Community and was authored by Bhaskar Sharma