Routing in Kubernetes is managed at the application level. CNI plugins handle correct routing to pods. Load balancing within the cluster is important.
CNI plugins interact with the underlying infrastructure (physical switches and routers) to manage these networking functionalities. They ensure that Kubernetes containers can communicate across nodes and with the external network while abstracting networking from the users.
Container Network Interfaces (CNIs) play a crucial role in Kubernetes network operating systems. They interact with networking components and enable various functions related to networking.
Containers can be compared to a virtual instance of a network device in a test setup.
When you launch a Docker image, it becomes an active container.
Containers run an isolated copy of their image on the host operating system, much like when you deploy a network function on a virtual device.
This isolation allows you to execute multiple containers independently on the same host without interference, akin to running multiple test cases on separate virtual devices.
A Dockerfile is a script composed of various instructions, each of which creates a layer in the image.
Similar to an automated test script that sequences actions to configure a test environment, a Dockerfile sequences actions that construct an image ideal for running a specific application.
The Docker Daemon is a background service running on the host that manages the building, running, and distributing Docker containers.
The daemon is responsible for handling the heavy lifting of ensuring that all platforms and applications based on Docker images run correctly.
The Docker Client is the command-line interface (CLI) that allows users to interact with the daemon.
It can be compared to the CLI or dashboard you use to control or configure network equipment or monitoring tools like IXIA, Spirent, or NAS equipment.
A container is like a virtual packet that encapsulates the application and its environment. Similar to how an IP packet encapsulates data and metadata for networking.
Setting up Docker involves installation and configuration, which can be compared to setting up network equipment. Just like installing firmware or operating systems for network devices, Docker setup requires following certain steps.
Note: If you find any mathematical expressions or code, I won't be able to summarize it. Please let me know if you need any other assistance.
daemon.json
file to define Docker's behavior, similar to configuring a switch or router.
systemd
to enable Docker to start on boot, similar to configuring a device to boot with a specific configuration.
Verify Docker installation by pulling an image and running a container.
To test the installation of Docker, you can follow these steps:
docker pull
command.
docker run
command.
By performing these steps, you can determine if Docker is installed correctly and running properly on your system.
docker run
: Runs a command in a new container
docker start
: Starts one or more stopped containers
docker stop
: Stops one or more containers
docker ps
: Lists all running containers
docker images
: Lists all available images
docker pull
: Pulls an image from a registry
docker push
: Pushes an image to a registry
docker build
: Builds an image from a Dockerfile
docker rm
: Removes one or more containers
docker rmi
: Removes one or more images
docker run:
Create a new container from an image
docker ps:
List all running containers
docker stop:
Stop a running container
docker start:
Start a previously stopped container
docker rm:
Remove a container
docker images
: List all images on the local system
docker pull
: Fetch an image from a registry to local machine
docker build
: Create a new image from a Dockerfile
docker rmi
: Remove an image from local storage
docker volume create
: Create a new volume that can be attached to containers to persist data
docker volume ls
: List all volumes
docker volume rm
: Remove a volume
Understanding Docker commands is similar to understanding CLI commands on a network device. However, instead of configuring network paths or policies, you are manipulating a container's lifecycle and the images they are based on.
Docker offers a straightforward CLI with logically named commands, which should feel natural for someone with your background.
A container image is a lightweight, standalone, executable software package that includes everything needed to run a piece of software, including the code, runtime, system tools, libraries, and settings.
Container images are used to manage the distribution of software, similar to how network elements have firmware images stored and managed for distribution and upgrades.
Container images use registries to manage the distribution of the images.
Docker Hub is a service that functions similarly to a code repository in Version Control Systems (VCS). It allows users to find and share container images.
docker pull
command
docker push
command
Docker Hub allows users to control who can view or edit their containers with public and private settings.
docker pull ubuntu:latest
docker tag my-image username/my-repository:my-tagdocker push username/my-repository:my-tagWhich benefit of containerization is analogous to VLANs in network equipment isolating network traffic?
What is a Dockerfile in Docker?
What is one of the key factors that differentiate containers and virtual machines (VMs) in terms of resource efficiency?
What is the role of Docker Engine in managing Docker containers?
What is one of the initial steps recommended for installing Docker on a Linux distribution?
What Docker command is used to create a new container from an image, similar to provisioning a network device with an initial configuration?
What is the role of container registries in the workflow of containerized applications?
Why is using a private container registry advantageous?