What is Docker?

You've likely heard about Docker. It's one of the big buzzwords currently running through the IT industry. Docker is a Linux container technology that lets us package and ship our applications and everything it needs to execute into a standard format, and run them on all our existing Linux hardware.

That might sound like a virtual machine, and it's a good start on how to think about Docker containers. Docker containers are similar to virtual machines in that our application runs on what seems to be it's own hardware instance. Every Docker container has it's own virtualized filesystem, memory, storage, CPU cycles and so on.

Where Docker containers differ is they virtualize the operating system kernel, not the hardware. That means we can't run any operating system, we have to run Linux. However, we also don't need to install an operating system for every application we want to run. This makes our containers very lean.

#java #docker #tutorial

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what-is-docker/

Concepts: Java, Docker, linux containers

Social Links: Don't hesitate to contact me if you have any further questions.

Related Videos:
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Deploy Java Apps Using Docker ➜

Media credits: All images are owned by DJ Spiess or used under CC0 unless listed below

[duyenho]

Love your videos. Thanks for making them!

[GueimeBr]

Your videos are very good! Congratulations. Please do more :)

[noytsarfaty]

Best videos!!!! Your smile and shiny eyes make it all less scary and give hope :) Keep up the great work! :)

[hinocenciopaulo]

I love your videos. You make any subject easy to understand! Thank you!!

[researchandbuild]

Great video, you know how to explain things in common sense terms ! We need more engineers like you. Most people use too much BS technical terms that dont make any sense

How good is docker for Windows environments i wonder? Can it handle the registry, etc?

[georgievvladimir]

great t-shirt and great video of course

[Kumar_Birendra]

Please upload the complete video for Node.js and Docker.

[user]

really simple and very helpful
thank you

[blackcity]

Hello,
Really nice videos and presentations!
Could you post a video on service discovery using docker containers please? (over 1 host or many hosts)

[jamesallen]

So am I understanding this correctly?

Assume two (2) docker containers are connected to the SAME OS and SAME DOCKER "engine". But each app, as far as they are concerned, they EACH individually "think" they are the ONLY app on that OS? One container doesn't even know about the other container.

So Docker visualizes the OS, not the hardware. Am I messing that up?

Followup question. What about the web server (apache, nginx)? Is it running at the OS level, or INSIDE the container?

[brunonegraozica]

Won't "docker build" command build the "image" and not the "container"?

[GenX-Memories]

Real-world, non-Docker IT user here: why would a person use Docker? What types of professional jobs use Docker? Why do people choose to learn and implement Docker?

[galaxydal]

Nice t-shirt and nice presentation. May I ask where did you buy this cool t-shirt ? :-)

[Suraj-uuil]

Hi Deege U, Really nice presentation, could you please give some idea or any video by which i can create our own repo in RHEL and copy our projects into that or copy any file into that. because everywhere i got only ubuntu, but i need to go with RHEL. Thanks

[JD-USA]

How does docker know what "ubuntu" is? Is there an OS image repo somewhere? And how can it install(?) ubuntu so quickly that it can echo "hello world" near instantly?

[tariqyounas]

If we need different OS for some reasons how we can achieve with containers? VMs can have different OS.

[rafaelvincere]

Excellent video. Horrible t-shirt though

[junaidtanoli]

i think this guy is dead or vanished, not uploading any more. ;(

[treymorrow]

I think it's hilarious that his communism t-shirt is covered by an ad.