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Searching images

Learn to search images with docker search.

Searching for images

docker search searches Docker Hub. The results show the star count and the OFFICIAL mark. Because many results come back, filters and limits are used:

$ docker search --filter is-official=true --limit 3 redis
NAME      DESCRIPTION                                     STARS     OFFICIAL
redis     Redis is the world’s fastest data platform …   13000     [OK]

For the tag list and detailed documentation, Hub's web page is more convenient.

Inspecting an image

Before running an image you can look at its contents: which user it runs as, its open ports, its entry point. docker image inspect gives these; docker scout cves lists known security vulnerabilities:

docker image inspect -f '{{.Config.User}} {{.Config.ExposedPorts}} {{.Config.Entrypoint}}' redis:7
docker scout cves redis:7

Practice Search and inspect

Write two commands: search only for official postgres images with at most 5 results; then show the exposed ports of the postgres:16 image with {{.Config.ExposedPorts}}.

Starter code

terminal
# buraya yaz

Sample solution

terminal
docker search --filter is-official=true --limit 5 postgres
docker image inspect -f '{{.Config.ExposedPorts}}' postgres:16

Expected output

NAME       DESCRIPTION                                   STARS     OFFICIAL
postgres   The PostgreSQL object-relational database …   14000     [OK]
map[5432/tcp:{}]

Questions and answers

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

1 When choosing an image from search results, what is the most reliable sign?

  • Having a long description
  • Being uploaded most recently
  • Being official (OFFICIAL) or a verified publisher Correct answer
  • Having a short name

Explanation: Anyone can upload images to Hub; unknown images may contain malware.

2 Search only for official images.

Question 
docker search --filter ____=true nginx
Answer 
docker search --filter is-official=true nginx

Explanation: is-official=true filters for official images.

3 Match.

Term Meaning
docker search Search Hub
[OK] OFFICIAL Official image
image inspect Show the configuration
scout cves Vulnerabilities

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