-
Section 1: Introduction
-
Section 2: Docker Basics for Beginners
-
Section 3: VPS — Rent Your Own Server
-
Section 4: Running Varyshop in Docker
-
Section 5: Building Your Website and Lead Magnet Page
-
Section 6: CRM — Managing Your Contacts and Leads
-
Section 7: Mass Communication — Email & SMS Marketing
-
Section 8: Conclusion and Next Steps
How Docker Works — Images, Containers, Volumes
How Docker Works
Images, Containers, and Volumes — the three core concepts
Docker has only three concepts you need to understand. Once you grasp images, containers, and volumes, everything else is just details. Let us walk through each one.
Images — The Blueprints
A Docker image is a read-only template that contains everything needed to run a piece of software: the operating system, libraries, application code, and configuration. Think of it as a snapshot or a recipe.
docker pull postgres:16 docker pull odoo:18
Docker Hub
Docker Hub is the public registry where thousands of pre-built images are available. PostgreSQL, Nginx, Python, Node.js — all ready to use.
Containers — The Running Instances
A container is a running instance of an image. You can start, stop, restart, and delete containers without affecting the image. Multiple containers can run from the same image simultaneously.
docker run -d --name my-postgres postgres:16 docker run -d --name my-odoo odoo:18
Lightweight
Containers share the host OS kernel. Starting a container takes seconds, not minutes like a virtual machine.
Isolated
Each container has its own filesystem, network, and process space. One container cannot interfere with another.
Disposable
Containers are meant to be created and destroyed. If something breaks, delete and recreate it from the image.
Volumes — Persistent Storage
By default, data inside a container is lost when the container is deleted. Volumes solve this by storing data outside the container on the host machine. Your database files, uploaded images, and configuration survive container restarts and updates.
docker volume create pgdata docker run -d -v pgdata:/var/lib/postgresql/data postgres:16
Never Skip Volumes
Without volumes, deleting a database container means losing all your data. Always use volumes for any data you want to keep.
How They Work Together
Pull an image
Download a pre-built image from Docker Hub or build your own from a Dockerfile.
Create a container
Start a new container from the image. Map ports and attach volumes.
Attach volumes
Connect named volumes to directories inside the container for persistent storage.
Run your service
The container starts the application. It is isolated, portable, and reproducible.
Remember
Image is the recipe, container is the running dish, volume is the pantry that survives between cooking sessions. Master these three concepts and Docker becomes simple.
Hlubší prozkoumání Docker konceptů včetně image, kontejnerů, volumes, Docker Hubu a klíčových příkazů, které budete v kurzu používat.
There are no comments for now.