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Summary - Registry

Combine login, search and pull to share images.

Summary: registry

In this group:

  • A registry stores images; the default is Docker Hub (docker.io/library/).
  • docker login authenticates; on CI the token is given with --password-stdin.
  • Official images are filtered with docker search and inspected with image inspect and scout.
  • Official images offer documented environment variables and conveniences like initdb.d.
  • Private registry: registry:2 or managed services; the name starts with the registry address.
echo "$TOKEN" | docker login ghcr.io -u ali --password-stdin
docker tag api:1.0 ghcr.io/ali/api:1.0
docker push ghcr.io/ali/api:1.0

Practice End-to-end publishing

Write three commands: log in to ghcr.io as ali from standard input with $GHCR_TOKEN; tag api:2.0.0 as ghcr.io/ali/api:2.0.0; push it.

Starter code

terminal
# buraya yaz

Sample solution

terminal
echo "$GHCR_TOKEN" | docker login ghcr.io -u ali --password-stdin
docker tag api:2.0.0 ghcr.io/ali/api:2.0.0
docker push ghcr.io/ali/api:2.0.0

Expected output

Login Succeeded
The push refers to repository [ghcr.io/ali/api]
2.0.0: digest: sha256:9e8d… size: 1789

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 Which registry does docker push ali/api:1.0 go to?

  • ghcr.io
  • localhost:5000
  • None
  • Docker Hub (docker.io) Correct answer

Explanation: With no registry address, Docker Hub is assumed.

2 Log out of the registry.

Question 
docker ____ ghcr.io
Answer 
docker logout ghcr.io

Explanation: logout removes the saved credentials.

3 Match.

Term Meaning
login Log in
tag Target name
push Push
pull Pull

All lessons in Beginner

1 What is Docker?

  1. What is Docker?
  2. Containers and virtual machines
  3. Images and containers
  4. Docker architecture
  5. Use cases
  6. Summary - What is Docker

2 Installation and first commands

  1. Installing Docker
  2. docker version
  3. docker info
  4. The hello-world container
  5. Docker Desktop
  6. Summary - Installation

3 First container

  1. docker run basics
  2. Running in the background
  3. docker ps
  4. docker stop and rm
  5. docker logs
  6. Summary - First container

4 Dockerfile basics

  1. What is a Dockerfile?
  2. The FROM instruction
  3. The RUN instruction
  4. COPY and ADD
  5. CMD and ENTRYPOINT
  6. Summary - Dockerfile

5 Build and images

  1. docker build
  2. Tagging images
  3. Build context
  4. Layers and cache
  5. .dockerignore
  6. Summary - Build

6 docker run options

  1. Interactive mode
  2. Naming containers
  3. Restart policy
  4. Working directory
  5. Switching users
  6. Summary - docker run

7 Image management

  1. docker images
  2. docker rmi
  3. docker pull
  4. docker push
  5. docker tag
  6. Summary - Image management

8 Port mapping

  1. The port concept
  2. The -p flag
  3. Multiple ports
  4. Random ports
  5. IP binding
  6. Summary - Port mapping

9 Volumes and data

  1. Data persistence
  2. Named volumes
  3. The -v flag
  4. Bind mounts
  5. Volume management
  6. Summary - Volumes

10 Environment variables

  1. The -e flag
  2. The ENV instruction
  3. The ARG instruction
  4. env-file
  5. The WORKDIR instruction
  6. Summary - Environment

11 Project: docker-compose

  1. Compose design
  2. Service definition
  3. Database service
  4. Volume and network
  5. Putting it together - compose

12 Docker Hub and registry

  1. What is Docker Hub?
  2. docker login
  3. Searching images
  4. Official images
  5. Private registry
  6. Summary - Registry

13 Network basics

  1. Network drivers
  2. docker network ls
  3. Bridge network
  4. Container connectivity
  5. Publishing ports
  6. Summary - Network

14 Beginner final

  1. Challenge - Dockerfile
  2. Challenge - Build and run
  3. Challenge - Volume
  4. Challenge - Compose
  5. Challenge - Beginner project