What is docker and kubernetes how to#
What is docker and kubernetes portable#
What is docker and kubernetes software#
What is docker and kubernetes code#

It doesn’t matter where he runs this command. This command will start running the app on port 80 of the host. He just needs to run the following command: docker run -d -p 80:80 dotnetapp So when he wants to run the app, only Docker needs to be installed.

What is docker and kubernetes portable#

He’ll only do the “build’ once because the idea is to make the app portable to run anywhere.

What is docker and kubernetes code#

This command will create an image with the compiled code and all of its dependencies to run. John needs to put that file in the root of the source code and run the following command: docker build -t dotnetapp.

What is docker and kubernetes how to#

The only difference is that you’re just defining all dependencies and declaring how to build and run the app.

# Copy csproj and restore as distinct layersĪs you can see, it’s as if you were programming. Take a look: FROM microsoft/aspnetcore-build:2.0 AS build-env NET Core app, and the Dockerfile looks like this.

A base image and all its dependencies are described in a file called “Dockerfile.” A Dockerfile is where you define something like a recipe that you usually have in docs (or in your mind) for anyone who wants to run your app. He learns that Docker containers work with base images as their foundation to run an app. Let’s say John decides to start his containers journey. I know that sounds like a textbook definition, so let’s see how this is beneficial by following the day in the life of John. Containers let you be more agile and build secure and portable apps, which lets you save some costs in infrastructure when done well.

What is docker and kubernetes software#

You might be thinking this sounds pretty similar to VMs, but the difference is that containers are more lightweight: they don’t need another OS to make software run. I mean “isolate” in the sense that containers can assign separate resources from the host where it’s running. Containers are a way to pack and isolate a piece of software with everything that it needs to run. Use Docker to pack and ship your appĭocker is a company that provides a container platform. The good news is that that’s where Docker and Kubernetes come into play. We all wish deployments could be as boring as pushing a button. Maybe John even has to spend a whole weekend doing deployments and fixing all sorts of broken things. That’s hard to do.Įven having automation in place, deployments might be too complex or painful. He has to work with production-like environments to ease deployments and reduce risk. But when we’re talking about production, things get risky. Now, he can screw things up in other environments too and then fix it, and that’s okay. He’ll still need to deploy changes in code and any dependencies to other environments. And then he has to somehow organize all the different versions of those VM snapshots. Why? Because every time something changes, he has to take a new snapshot. That way, he can isolate all dependencies and avoid affecting any existing apps and their dependencies One solution could be for him to work with virtual machines (VMs). It’s kind of hard to remember all the steps when we’re in a rush. The struggle becomes even bigger when he has to push a new change after doing all of that to another environment. When something’s not working, he just installs, uninstalls, updates, or removes until finally things get back up and running. The problem is when things aren’t compatible with what he’s installed. He struggles every time a new version of the language, framework, or library comes out and he has to run an upgrade. John’s a developer working for a startup, and he’s responsible for deploying his code to a live environment. For practical purposes, we’ll talk about the fictional developer John Smith.

Then I’ll explain how these two technologies can help. So let me start with a typical day in the life of someone who struggles through every deployment. Everything starts with your local environment