What you will learn

1. Containers.

   • Container Registries.

   • Container Orchestration.

2. Docker.

3. Kubernetes.

   • OpenShift.

   • Istio

Understanding the Benefit of Containers

Introduction to Containers

• • A container is a standard unit of software that encapsulates everything that programmers need to build, ship, and run applications.

  • Why uses Containers:

    1. Isolation and Allocation.

    2. Server Utilization

    3. Provisioning and Costs.

    4. Portability

    5. Resiliency.

    6. Scalability.

    7. Automation.

• • Characteristics:

    1. Virtualizes the operating system.

    2. A container is light-weight, fast, isolated, portable, and secure.

    3. Require less memory.

    4. Binaries, libraries within container enable apps to run.

    5. One machines can host multiple containers.

• • Challenges:

    1. Security impact.

    2. Difficult to manage.

    3. Complex to migrate legacy projects to container technology.

    4. Difficult to right-size containers for specific scenarios.

• • Container Vendors:

    1. Docker.

    2. Podman.

    3. LXC.

    4. Vagrant.

Dockers

• • Is an open platform, or engine, where programmers can develop, ship and run applications.

  • Written in Go Programming language.

  • Uses the namespaces technology to provide an isolated workspace called "container".

Benefits of Dockers

• • Consistent and isolated environments.

  • Fast development.

  • Repeatability and automation.

  • Support Agile and CI/CD Devops practices.

  • Versioning for easy testing. rollbacks, and redeployments.

Building and Running Container Images

• • Docker container creation process:

    1. Create a Dockerfile.

    2. Use the Dockerfile to create a container image.

    3. Use the container image to create a running container.

  • Use a Dockerfile to create a running container:

    1. Dockerfile has the commands FROM and CMD.

    2. FROM: Defines the base image.

    3. CMD: Prints the words "Hello World!" on the terminal.

  • Ex: FROM alpine CMD ["echo", "Hello world!"]

• • Create a container image using the build command:

• • Docker Images: $ docker images

• • Create the container using the run command:

• • To verify the details of the container created, run the docker ps -a command:

• • Docker commands:

Docker objects