Hands-On

• Launch containers with docker run redis

  
• docker version to view details about the Docker client and server.

  • Docker is a two-part system: client and engine communicate via various protocols.
• • docker run -d -p 8800:80 httpd
  • -d: Detach, runs the container in the background.
  • -p 8800:80: Publishes container's port 80 on host's port 8800.
  • httpd: Apache HTTP server image.
• • Use curl localhost:8800 to verify the Apache server
  • Run docker ps to display running containers; you should see one.
  • To run a second Apache server on a different port, execute:-docker run -d -p 8801:80 httpd
  • Docker downloads the image and creates separate containers (Container 1 and Container 2).
  • Each container has a private IP with port 80 inside Docker's virtual networking.
  • External ports (8800, 8801) map to the containers' internal ports.
• 1. Docker Version:

  • Command: docker version
  • Returns the version of the Docker client and server (engine).
  • Ensure both client and server versions are up-to-date for optimal compatibility.

  1. Docker Info:

  • Command: docker info
  • Provides detailed information about Docker engine configuration.
  • Includes data on containers, images, and other engine settings.
• Review of Commands:

  • docker version: Check client and server versions for compatibility.
  • docker info: Obtain detailed information about Docker engine configuration.
  • docker: List available Docker commands.
  • Command Structure: Old commands (e.g., docker run) coexist with new management commands (e.g., docker container run).
• 1. Image vs. Container:

  • Image: Binaries, libraries, and source code that constitute an application.
  • Container: A running instance of an image.
  • Multiple containers can be based on the same image.

  1. Image Registries:

  • Registries (e.g., Docker Hub) host container images, analogous to GitHub for source code.
  • Docker images are pulled from registries when needed.
• Practical Exercise: Running Nginx Container

  • Use the command: docker container run -p 80:80 nginx
  • Explain the command parts:
  • -p 80:80: Publishes local port 80 to container's port 80.
  • nginx: Specifies the image (Nginx web server).
  • Access Nginx server in a browser at localhost.

  1. Listing and Stopping Containers:

  • List running containers: docker container ls.
  • Stop a container: docker container stop <container_id>.
• 1. Container Logs:

  • Generate logs by refreshing the browser.
  • View logs with: docker container logs <container_name>.

  1. Inspecting Containers:

  • Use docker container top <container_name> to view container processes.
  • Explore additional container commands with docker container --help.
• docker container ls -a

  • lists all containers, including ones that have been stopped
• removing multiple containers:

  • docker container rm {ids of containers}

  Note: You cannot remove a running docker container, you first must stop it or use this command to force remove it:

  • docker container rm -f