What is Docker?

Summary

This video delves into Docker, an ecosystem for creating containers that encapsulate applications with their dependencies, ensuring consistent performance across development, testing, and production environments. It contrasts Docker with hypervisors, highlighting Docker's efficiency by sharing the host OS among containers, thus conserving resources. The video also touches on Docker's components, such as Docker Hub and the Docker engine, and mentions the availability of pre-built images, making it easier to deploy applications. The speaker invites viewers to explore Docker further, hinting at its utility in upcoming tutorials.

Takeaways

• 😀 Docker is an ecosystem that facilitates the creation and management of containers, which are isolated environments that can run applications consistently across different computing environments.
• 🛠️ The need for Docker arises from the challenges developers, testers, and operations teams face in ensuring that applications run smoothly across different environments due to varying dependencies and libraries.
• 💻 Developers often use frameworks and libraries that require specific versions or dependencies, which can lead to compatibility issues when the application is tested or deployed on different systems.
• 🔄 The 'it works on my machine' problem is a common issue where an application runs perfectly on a developer's system but fails on a tester's or production server due to differences in dependencies and environment configurations.
• 🌐 Hypervisors, like virtual machines, solve some of these issues by allowing multiple operating systems to run on the same hardware, but they can be resource-intensive and require multiple licenses.
• 📦 Docker containers, unlike hypervisors, do not require a separate OS for each application, sharing the host OS's kernel and only isolating the application and its dependencies, thus saving resources.
• 🚀 Docker images are snapshots of a container that can be shared and used to create new containers, ensuring that the application and its environment are consistent across different machines.
• 🔄 Docker Hub is a public repository where users can find and share Docker images, making it easy to deploy applications that require specific environments or dependencies.
• 🏢 Docker, the company, offers both a community edition (Moby) and an enterprise edition, with the latter providing additional support and features.
• 🔧 Docker's client-server architecture includes a Docker engine that manages the building, shipping, and running of containers, streamlining the development and deployment process.

Q & A

What is Docker and why is it needed?

Docker is an ecosystem that allows for the creation and use of containers, which are lightweight, portable, and self-sufficient software packages that include everything needed to run a piece of software, including the framework, libraries, dependencies, and even the OS-level features. It is needed because it provides a consistent environment for developing, shipping, and running applications, ensuring that they work seamlessly across different systems and platforms.

How does Docker help in the software development lifecycle?

Docker streamlines the software development lifecycle by enabling developers to create containers with all the necessary dependencies and configurations. This ensures that the application runs consistently from development to testing to production, eliminating 'works on my machine' problems and reducing dependency conflicts.

What is the problem with dependencies when shipping an application without Docker?

Without Docker, when an application is shipped to testing or production environments, there can be issues with dependencies due to version mismatches or missing libraries. This can lead to the application not running as expected, causing delays and additional work to resolve these discrepancies.

How do virtual machines compare to Docker containers in terms of resource usage?

Virtual machines (VMs) run a full guest operating system on top of a hypervisor, which can be resource-intensive as each VM requires its own OS. In contrast, Docker containers share the host OS kernel, making them more lightweight and efficient in terms of CPU, memory, and storage usage.

What is a Docker image and how is it used in the containerization process?

A Docker image is a read-only template that contains the application, its dependencies, libraries, and configuration files. It is used to create containers by defining the environment in which the application will run. Once an image is created, it can be used to spawn multiple containers that are consistent with the application's intended environment.

Why might a company choose to use Docker over traditional hypervisor-based virtualization?

Companies might choose Docker over traditional virtualization because it is more resource-efficient, faster, and provides a more consistent environment for applications. Docker containers are also easier to manage and scale compared to VMs, and they can simplify the deployment process across different environments.

What is the Docker Hub and what role does it play in the Docker ecosystem?

The Docker Hub is a cloud-based registry service that allows users to link code into images, collaborate on projects, and share images with other users. It serves as a central repository for Docker images, making it easier to distribute and manage containerized applications.

How does Docker help in avoiding the 'it works on my machine' problem?

Docker helps avoid the 'it works on my machine' problem by ensuring that the same environment, including all dependencies and configurations, is used across different stages of the development lifecycle. This consistency means that if an application runs on one developer's machine, it should also run the same way on testing and production environments.

What are some of the benefits of using Docker for application deployment?

Using Docker for application deployment provides benefits such as faster deployment, easier scaling, consistent environments, and reduced overhead compared to traditional deployment methods. It also simplifies the management of application dependencies and allows for the quick creation and management of application instances.

How can Docker be used for educational purposes or demonstrating tools?

Docker can be used for educational purposes by creating containers with specific software, frameworks, or tools pre-installed. These containers can then be shared with students or users, allowing them to quickly and easily access the required environment without needing to install anything on their local machines.

What is the difference between Docker's community and enterprise versions?

Docker's community version is open-source and free to use, while the enterprise version offers additional features and support for a fee. Both versions have similar core functionalities, but the enterprise version is tailored for businesses that require more robust support, security, and scalability.

Outlines

00:00

🐳 Introduction to Docker

The paragraph introduces Docker as an ecosystem for creating containers to run applications. It discusses the need for Docker from the perspective of developers, testers, and operations teams. The main challenge highlighted is the dependency issues that arise when an application is built with specific frameworks and libraries, which might not be the same on the tester's machine. The paragraph emphasizes the importance of ensuring that the application runs consistently across different environments, which is where Docker's containerization comes into play.

05:00

🔧 Hypervisors and the Problem They Solve

This paragraph delves into the concept of hypervisors and virtual machines as a solution to dependency issues. It explains how a hypervisor allows for the creation of virtual machines, each with its own operating system, thus encapsulating the entire environment needed for an application. The paragraph outlines the process of shipping a virtual image to testers and production, ensuring that the application runs as expected without dependency clashes. However, it also points out the inefficiencies and resource wastage associated with running multiple operating systems on the same hardware.

10:01

📦 Containers: The Docker Advantage

The final paragraph contrasts Docker containers with hypervisors, highlighting that containers do not require separate operating systems, thus sharing the host OS and saving resources. It discusses how Docker allows for the creation of containers from images that include the application, its dependencies, and the necessary environment. The paragraph also touches on the ease of sharing and reusing these images, the Docker ecosystem, and the company behind Docker. It concludes by hinting at the practical application of Docker in high-performance computing and encourages feedback for further exploration of Docker concepts.

Keywords

💡Docker

Docker is an open-source platform designed to make it easier to create, deploy, and run applications by using containers. It packages software into standardized units that contain everything needed to run, including the code, runtime, system tools, libraries, and settings. In the video, Docker is discussed as a solution to the problem of dependency clashes and inconsistent environments across development, testing, and production stages.

💡Containers

Containers are lightweight, standalone, and executable software packages that include everything needed to run a piece of software, including the code, runtime, system tools, system libraries, and settings. They allow developers to package up applications along with their dependencies and ship them as one package to any environment. In the video, containers are presented as a more efficient alternative to hypervisors, allowing multiple applications to run on the same OS without the need for multiple OS installations.

💡Dependencies

Dependencies refer to external libraries, frameworks, or services that an application relies on to function properly. In the context of the video, dependencies are crucial because they can cause compatibility issues if different versions are used in development and testing environments. Docker helps manage these dependencies by packaging them with the application in a container.

💡Development

Development in the video refers to the process of creating software applications. Developers use various frameworks and libraries to build applications, and Docker can be used to ensure that the application, along with all its dependencies, is packaged in a container for consistent deployment across different environments.

💡Testing

Testing is the phase where the application is checked for bugs and errors before it is deployed to production. The video discusses how inconsistencies in dependencies can lead to issues during testing. Docker helps by providing a consistent environment for testing, ensuring that the application behaves the same way as it does in development.

💡Production

Production refers to the final stage where the application is deployed to a server and made available to end-users. The video highlights the importance of having a consistent environment in production as in development and testing, which Docker facilitates by using containers.

💡Frameworks

Frameworks are pre-built software structures that provide a foundation for developing applications. Examples mentioned in the video include Spring Framework for Java and Django for Python. Docker can package these frameworks along with the application into a container, ensuring that the application runs the same way in any environment.

💡Hypervisors

A hypervisor is a software that allows multiple operating systems to run on a single physical host by creating virtual machines. In the video, hypervisors are discussed as an initial solution to dependency issues but are considered resource-intensive because each virtual machine requires its own OS.

💡Docker Hub

Docker Hub is a cloud-based registry service that allows users to link code repositories, build images, and store them. It's a central place to share and collaborate on container images. The video briefly mentions Docker Hub as part of the Docker ecosystem, where users can pull pre-built images to quickly set up environments.

💡Docker Engine

Docker Engine is the underlying technology that powers Docker and enables the creation and management of containers. It's a client-server architecture that includes a daemon, client, and a REST API. The video touches on Docker Engine as part of the broader Docker ecosystem, which facilitates the use of containers.

💡Images

In the context of Docker, an image is a read-only template with instructions for creating a container. It includes the application, its dependencies, and the necessary configurations. The video explains that developers can create an image of their application and its environment, which can then be used to create containers in testing and production.

Highlights

Docker is an ecosystem for creating and running containers.

Docker helps in providing software to users by facilitating the development, testing, and deployment process.

Developers use frameworks and dependencies to build applications, which can lead to version clashes during testing.

The 'works on my machine' problem is a common issue due to different environments and dependencies.

Hypervisors, like virtual machines, allow for the creation of virtual OS images to solve dependency issues.

Virtual machines can be resource-intensive and require multiple OS licenses.

Docker introduces the concept of containers that share the same OS kernel, reducing resource usage.

Containers can be created from images, which package the application and its dependencies.

Docker images can be shared and pulled from public repositories, simplifying the setup process.

Docker's client-server architecture includes a Docker Engine that manages the containers.

Docker offers both community and enterprise versions, with the latter providing additional support.

Docker can be used to create custom environments for teaching or demonstrating tools without installation.

Docker Hub is a platform for sharing and managing Docker images.

Docker's ecosystem includes a variety of tools and services that facilitate containerization.

The video discusses the potential for a series on Docker for further in-depth exploration.

Docker is set to be utilized in high-performance computing scenarios.

Transcripts

[Music]

welcome back aliens monuments of Nvidia

in this video we'll talk about docker

docker is basically an ecosystem where

you can create containers where you can

run containers but then why do we need

it see we can talk about this docker in

detail but then the main question is why

do we need Dockers now think about this

as a developer or as a tester or as

operation team what we do is we work

with Sophos like the ultimate thing is

to provide a software so that your user

can use it I'm talking about the web

application now all web services so what

we do is we build an application

normally development team they pay a

software and then this soffit goes for

the testing so testing team will be

doing the testing on it all and then

after that if everything is going good

of course if something goes wrong it it

comes back to development team but what

if everything is perfect then goes for

the operation team so that they can

deploy the application on broad server

of course depend upon company this

process might change but then we have

these steps right there look the

application there's the application and

ship it to the production server so that

we can run there one thing is when as a

developer when you build an application

you might be using some framework so

let's say if you're working one job or

you might be using Spring Framework

maybe you want to build a web

application using using Python so you'll

be using Django framework so what we do

is when when we want to build an

application we have a framework and this

framework will need certain libraries

some dependencies or maybe some O's

level features so what we do is when you

want to start with the application you

need before even before touching the

application you have to download

dependencies you have to download the

libraries now the thing is after

researching which library to use after

is searching with dependence that you

use you will download them and you will

have those things on your machine so you

have your framework you have your

application you have your dependencies

and maybe some postal features now

everything is done right your product is

ready with you and of course the next

step would be testing so you will ship

this product to the ship to the testing

team but the problem is the testing team

when they start using your application

they might face issues so there's

nothing wrong with the software what

went wrong is with with the dependencies

because the dependency which you have

used of course you have list them all

the dependencies which are required so

they might be download

those dependencies or maybe you are

sending those dependencies in a jar file

or dinner in a zip file the problem is

it's not just the number of dependencies

it's also the versions right so maybe

you have used our version 4.2 and then

they might be using 4.0 so there will be

a clash your software will generate

issues the problem is with the

dependencies and the libraries and

sometime you know what happens when you

are building an application your

application may need some extra

dependencies which even you are not

aware of so what happens is maybe you

have worked on some earlier projects and

those projects needed some dependencies

which you have in your machine but the

same thing is not there in the tester

machines but testing team will say hey

developer something went wrong something

went wrong because of you and you will

be saying hey it was working on my

machine is not working on your machine

so it's something wrong with your

machine we can have a blame game there

but that's not happen if it happens in

the company but then we can you might

imagine a scenario right they might be

thinking this in the in their head so

what if you can when you when you are

shipping the application the application

which you have build not just

application but you have to ship

everything the framework dependencies

and that is everything so you will take

take the entire stuff and give it to the

testing team but is it possible is it

possible to give everything the thing is

some dependencies and libraries are

dependent on the OS so you have to give

the entire OS and that's not practically

possible right you find copy or say -

haven't give it to someone else and

that's where we got a solution and that

solution is hypervisor okay if you don't

know about hypervisors think about

virtual machines all VM very few that's

very famous software which you might

have used in your polish days or in your

company so what we do using the virtual

machine is so you have a hardware so you

have a physical hardware and on that

hardware you install an OS of course

every app every machine has arose maybe

Windows or Linux based OS for Macintosh

now on that OS you will be installing a

hypervisor or VMware basically now this

VMware can install another OS now the

amazing thing is when you install the

new OS now this OS can be back and you

can ship it so you can create an image

of it so the amazing thing is when you

give this OS to someone else they can

load it the same OS and this OS will

have everything so what I'm saying is a

Hardware OS hypervisor

and you're always the customers or the

or the virtual OS now on this virtual OS

okay you can do anything you want you

can install software you can install

dependencies you can you can build an

application now when you're giving the

application to the testing team don't

just give the software give the entire

image of your OS the virtual image which

you say and then once they get the image

they can create an instance of it so

basically you can imagine the concept of

classes and objects in Java when you

give up class they can create objects

they can do it instances of it of course

you can't the running image but you can

run instances with one image you can

have multiple instances running so you

can have ten instance if you have

hundred instances so that's amazing

right so the testing team will they will

run the instance now the amazing thing

is they don't have to worry about

dependencies because you have given them

everything the software which you have

built libraries dependencies and maybe

some oysters features now they will be

testing the application not the

dependencies but they will test your

your logic and everything is working or

not and then if everything goes well

even they don't have to I know think

about the production server they can

simply create a virtual image again the

new image we making after making some

changes and give it to the production

now production will have the image they

will get the image and the ops team they

will simply clear instance everything is

running right so if if this software

works on your machine it will also work

on the server that's great right that's

the concept of hypervisors but then

something went wrong right because the

the title of the video talks about

docker in fact in the start of the video

I've said hey we will talk about docker

and I'm talking about hypervisors so the

problem with hypervisor is it's a great

concept right so if hypervisor was

perfect we don't even need Dockers but

the thing is hyper was I still agreed

okay there are lot of application there

a lot of companies they're still using

hypervisors for various reasons might

for one of the reason why hypervisor is

not referred is the the thing is when

you install in OS when you install the

hypervisors and then you have to install

another OS now what if you have a server

and then you want to run multiple

application so imagine every application

will need its own OS then that will be

bulky right so you are basically running

multiple operating system on this

same hardware the same physical hardware

so you're wasting resources okay but

necessary sauce you're wasting CPU

you're wasting Ram you are wasting

harddrive you are wasting all the

resources this the next issue is with

the licenses what if the OS which are

using is Windows OS so of course you

have to buy those licenses or even if

you are using appropriate with index

based OS you have to buy licenses for

license for that so we don't want to

invest at of that much of money so we

got a concept of containers no thanks to

Linux containers which is lxv we can

have a container systems

now what continuous are is think about

containers as hypervisors the only

differences in containers we don't

install Newars so all the containers

will share the same they will share the

same OS cardinal and that's beauty right

so on the hardware you will be having OS

on that always will be installing docker

not hypervisor docker and on this docker

you can have multiple containers and

each container can run its own

application the full-fledged application

your application dependencies everything

that that's awesome right so that's the

concept of containers now this container

can be created with the help of images

now go back to the example as a

developer you will be having a physical

hardware on that hardware you will be

installing an OS on that OS will be

installing dock and on docker you can

create containers now once you build

into the application you just have to

pack the application that you have to

pack the container now when you pack a

container it will create a image now

this image goes to the tester they can

create multiple containers they can

create multiple instances and each is

just we can call it as containers again

the same concept imagine image as as a

class and if you have multiple

containers as objects and if you create

two container of the same image they

will behave in the same way okay because

they are the containers there are these

juices of the same image so now when

testing team has this they can again

they can do testing and then when this

ship when this ship this product to the

production server again they will again

give the image and on the person's away

you can run containers and container

will have everything they just need a

docker system there and it can run the

application now the beauty is you can

create your own container so let's say

if I want to teach the spring framework

to someone and or maybe I want to

demonstrate some tool so of course they

don't have to install the software so

what I can do is on my machine I will

install

docker and I can create container with

multiple libraries and Spring Framework

and then I can give them the container

the image now they can run the image on

their machine on their taco right so we

can also share the images and that's why

if you go to the public repository of

docker they will have all the they were

had they have most of the repositories

they have most of the images so you can

use those images example they have image

for for ladies they have image for Noah

so they have image for the window as

well so if you want to run to this

application just use docker pull the

image run it on your machine and you can

you can get started right that's the

people test the beauty now come back

coming back blocker the docker is a

ecosystem as I mentioned in docker we

have so many things to talk about we can

talk about chocolate hubs so the deposit

ways which I'll talk about talking about

it was a docker hub then we have a

concept of docker engine so you know we

have a client-server architecture where

we have a server when you have a client

of course we can talk talk about those

things in detail it's not a small topic

you talk about right so it has so many

things involved inside docker so doctor

is also a company now when you say you

work with docker so that's a company

they are talking in fact doctor also has

an enterprise version so they have a

community version they have Enterprise

version committee was is open source and

they have named it mobi and their the

Enterprise version as well the feature

is almost same it's just that for the

enterprise version they provide support

so that's the introduction of dropper

let me know if you if you want to know

some more concepts about this I can make

a series on talk anyway we are going to

use this concept in high polish of

fabric goes so yeah that's it that's

about docker so I hope you enjoyed this

video write me in the comment section

and use it for the videos