What is Docker?
Summary
TLDRThis 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
🐳 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.
🔧 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.
📦 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.
Mindmap
Keywords
💡Docker
💡Containers
💡Dependencies
💡Development
💡Testing
💡Production
💡Frameworks
💡Hypervisors
💡Docker Hub
💡Docker Engine
💡Images
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
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