Docker Tutorial for Beginners | Docker Container | What is Docker? | Learn Docker | Edureka

hi folks this is vaudeville America today I'm going to tell you why doctors the hottest technology in the devop scene doctor is a software containerization platform if you don't know what that is then you don't need to worry because I will explain it in detail in today's session now before we move forward let me show you the agenda for today in the first section of this video you will understand the subtle difference between virtualization and containerization and you will learn how containerization is an upgrade to virtualization I will then tell you what is docker and show you what comparative analysis between virtual machines and docker containers proving out docker comes out on top in every aspect after that I will talk about Dockers working architecture the second section of this video will be a practical hands-on session where I will show you how to build your own images and it's been continuous all of them this also happens to be a practical lab Neturei karta ops course so first let's talk about the difference between virtualization and containerization virtualization is the technique of importing a guest operating system on top of a host operating system this technique was a revelation in the beginning because you have developers run multiple applications in different virtual machines all running on the same host this eliminated the need for extra hardware resource and enable backup allowing for easy recovery in case of failure conditions thereby lowering the total cost of ownership but virtualization has some shortcomings running multiple VMs in the same host OS leads to performance degradation this is because of a guest OS running on top of the host OS which will have its own kernel and its own set of libraries and dependencies this takes up a chunk of the system resources another problem with virtual machines which uses virtualization is that it takes almost a minute to boot up this is very critical in case of real time applications where fast processing is a priority this along with the fact that's carrying up the number of virtual machines being a tedious and costly affair gave rise to containerization but what is containerization it is a technique of bringing virtualization to the operating system level while virtualization brings abstraction to the hardware containerization brings abstraction to the software do note that containerization is also a type of virtualization containerization is more efficient because there is no guest OS here binaries and libraries of containers are run on the host kernel which makes processing and execution very fast even booting up a container takes only a fraction of a second because all the containers run on the same host they are lightweight and faster than virtual machines folks to make this video more interactive I will post a number of questions and expect answers from you I will do this to check we wanna so the concepts properly you can pause the video for a few seconds to read the question and you can put your answers in the comment box if you don't know the answers you can rewind the video to the previous slides and learn every moneyö detail and then comment your answers in the comment box this is the first of the many questions I will be asking you today which is the below options is incorrect containerization is rebasing virtualization containerization brings profits level isolation and hypervisors manage the virtual machines the correct option is continuation is replacing virtualization that is because this statement is not correct it is not replacing virtualization it is just the next step in the evolution process there are still many circumstances where virtualization is a better option if you want to run an application in the Linux machine and if you have a Windows machine then you cannot run the application and at that point of time hosting a do not VM on your Windows machine would be very beneficial I will ask you many such questions in this video so what is the entire video to have fun while learning now let's see what is docker docker is a software container ization platform which packages your application and all its dependencies together in the form of containers so as to ensure that your application works seamlessly in any environment be it development or test or production this means that each application will run on a separate container and will have its own set of libraries and dependencies this also ensures that there is process level isolation meaning each application is independent of other applications giving developers surety that they can build applications that will not interfere with one another as a developer I can build a container which has different applications installed on them and give it to my QA team we'll only need to run the container to replicate the developer environment you may have questions like how does this help it helps because the QA team need not install all the dependents are and applications to test the code helping them save lots of time and energy this also ensures that the working environment is consistent among all the individuals involved in the process the number of systems can be scaled up easily and the code can be deployed on them effortlessly now let's learn in detail the benefits of docker our virtual machines the image you can see on a screen is very typical of how docker is when compared to virtual machines the space consumption in case of a virtual machine and docker can be related to the comparison of space occupied by an elephant and a rack starting up a virtual machine and starting docker can be related to the difference in speed between a tour toys and a cheetah and when it comes to integration virtual machines will say what on earth does integration where as docker can be comfortably integrated with many DevOps tools for automating manual processes now let's talk about this more detail consider a hypothetical situation where I have a system with 16 gigabytes of RAM and have to run three virtual machines on it to run the virtual machines I divide my RAM such as my first VM gets 6 GB of RAM my second VM gets 4 GB of RAM and my third VM gets the remaining 6 GB now even if my first VM uses only 4 GB of RAM my second VM uses only 3 GB of RAM and my third BM usually 2 GB of the allotted 6 GB of RAM then I will be wasting 7 GB of RAM in total this 7 GB of RAM cannot be used for setting up a new virtual machine because once any virtual machine is allocated memory it cannot be taken back later this is a major issue because Ram is a very costly Hardware now how can I avoid this problem if I use docker my CPU will only allocate the docker container exactly the amount of memory that will be used my first container will be using only 4gb of memory the second container will be using only 3 GB of memory and my third container will be using only 2 GB of memory since there is no RAM that is allocated on unused I save 7 GB of memory by using docker I can even create additional containers from the leftover Ram now when it comes to start up virtual machines take a lot of time to boot up because the host system needs to be set up first which will then run the hypervisor which will in turn set up the different virtual machines this is time consuming and will prove very costly at times when quick startup of applications is needed in case of docker since the container will be running on your host OS you would be saving precious boot up time this is a clear advantage of of virtual machines so consider a situation where I want to install different versions of Ruby on my system if I use virtual machines then I will need to set up two different virtual machines for running the different versions each of these will be having its own set of libraries and binaries were running on different guest operating systems whereas if I use docker even though I will be creating two different containers where each container will be having its own set of binaries and libraries I will be running them on my hosts OS running them straight on my host OS makes my system lightweight and faster this is the advantage with docker but what about integration integration of different tools using virtual machines may be possible but even that possibility comes with a lot of complications I can now only a limited number of devops tools running on a virtual machine as you can see from the screen if I want many instances of Jenkins and puppet then I would need to spin up many virtual machines because each virtual machine will have only one running instance of these tools setting up each virtual machine brings with it infrastructure problems I will have the same problem if I have to setup multiple instances of ansible Nagios selenium and gate it will also be a hectic task to configure these tools in every virtual machine this is where docker comes to the rescue using docker containers we can setup many instances of Jenkins puppet and many more all running in the sea container or running in different containers which can interact with one another by us running a few commands I can also easily scale up by creating multiple copies of these containers so configuring them will not be a problem summing it all up I can confidently say that docker is a more sensible option when compared to words and machines learn more about how different tools can be integrated using docker please watch our video titled DevOps tools you can find the link to that video on your screen and in the description below folks it's time for our next question suppose I have a system with only 4gb of RAM and I want to run four instances of a particular DevOps tool then which of the below is the best choice for VMs with four different instances of that tool one VM with four different instances of that tool or four different docker containers with different instances of that tool do take your own sweet time to answer this question you can put the answer in the comment box which will validate at the earliest and the correct answer is docker containers that's because docker containers utilize very less RAM and compatible machines another advantage here is that these four docker containers will be running on the same host operating system making your system lightweight and faster and the other thing is that virtual machines cannot be used here because each virtual machine requires at least 1 GB of RAM and we do not have that much resource since our Rama is only 4 GB we cannot use a complete 4 GB on virtual machines but in case of docker there is no need to pre allocate RAM and hence docker is the obvious winner here so who can use docker the answer is everybody docker is designed to benefit both developers and system administrators making it a part of many DevOps tool chains developers can write their code without worrying about the testing or the production environment and system administrator's do not worry about the infrastructure as docker can easily scale up and scale down the number of systems for deploying on the servers so how is docker used in DevOps doctors used 90% of the time in the continuous testing phase and probably 10% of the time in the continuous deployment phase dhaka plays a major role in the continuous testing because it sets up the testing environment it is also used to deploy the code to production and that's how it plays its role in the continuous deployment phase let's now look at how docker works docker engine is the heart of the docker system it works like a client-server application matures a server which is the type of a long-running program called a daemon process and a command line interface climbed the REST API with the combination of a socket IO and a tcp/ip connection is used for communication between the CLI klein and the docker demon in an energy operating system there is a dark line which can be accessed from the terminal and a docker host which runs the docker demon we build a docker images and run the docker containers by passing commands from the CLI client to the dock a demon but in case of Windows or iOS there is an additional docker toolbox component inside the docker host this docker toolbox is an installer to quickly and easily install and setup a docker environment on your windows or an iOS system the docker toolbox installs docker client machine compose kite ematic and VirtualBox ok now it's time for the next question how does the communication happen between the docker client and the docker demon is it through the REST API is it a combination of the REST API in the socket IO or is it a combination of the REST API and the TCP or is it just the combination of the REST API socket IO and TCP you can pause the video here and put the correct option in the comment box and then resume the video and the correct answer is the combination of REST API socket IO and TCP even though the rest the API is the primary mode for communication the dock edemen can listen to the remote API requests where are three different types of socket Unix TCP and empty this information might not be there on the slides but I specifically mentioned this a couple of back and folks that is why I request you to please be attentive in class so moving on to our next topic let me tell you what our images and containers images can be related to an executable file images are the building blocks of a docker container these docker images are created with the build command and these read-only templates are used for creating the containers by using the run command continue to the ready applications are created from the images containers are instances of images and they hold the entire package that is needed to run the application the docker registry is where our images are stored the registry can be either a user's local repository or a public repository like a dr. Hopp so that multiple users can collaborate and building an application even multiple teams within the same organization can exchange your shared containers by uploading them to the docker hub docker hub is Dockers very own cloud repository very similar to a github let us now understand the docker architecture in detail we have dr. client a doctor who is running the docker demon and a docker registry the docker demon is responsible for the images and the containers now if I have to build docker image I have used a CLI to issue a build command to block a demon the docker demon will then build an image based on my inputs and save it in my registry which can be either a docker hub or my local repository if I do not want to create an image then I can just pull an image from the docker hub which should have been built by a different user and finally if I want to create a running instance of my docker image I can issue a run command from my CLI which will create my container this my folks is a simple functionality of docker ok folks it's time for a couple of more questions which is the below options is correct with respect to creating docker containers I can build my own image and used for creating a docker container I can pull an image from the docker hub and then run the docker image or I can directly create it off a container without the docker image do take your sweet time and comment your answers both option one and option two are correct because you first bill your image and then you create a container if you don't want to build your image you can just pull an image from the docker hub and then run that image and create a container out of it but the third statement says that I can directly create a container without the docker image this statement is false and that's why the first two options are correct now let's move to the next question where does the docker demon store the docker images is it in the docker client from where the users type the commands or is it from the docker host which is running the docker demon or is it the docker registry the correct option is docker registry all the docker images are stored in the docker registry which can be either a local repository or a remote docker hub this is the second section of the video where I will be showing you some practical hands on these are some of the basic commands in docker to pull a docker image from the docker hub we can use the command docker pull image name colon tag the tag specifies the version of the image the different versions of the image are identified by the time to run that image we can use the command docker run and image name or docker on the image ID to list down all the images in our system we can give the command docker images to lets down all the running containers we give the command docker PS and to list on all the containers whether they are running or not we give the command docker PS - a now let me run a sample hello wall container and show you how docker works let me go to my terminal so here I am on my term loop let me first run the command docker images this lists down all the images that are in your system since there are no images there are no entries for me same thing with docker PS as you can see there are no running containers so there are no entries let me show you by running a sample HelloWorld container how docker works the command is docker run HelloWorld since the hollow wall container is not present in my local repository it will pull this container from the docker hub as you can see it says pulling from library hello world this is the image and it says pull complete and here is your message hello from docker this message shows that your installation appears to be working correctly now let me run the docker images command again as you can see there is a new image that's created with this ID let me do the docker PS command and this is the hollow wall container that's created now that you know water docker images and doctor containers let me show you how to build your own docker images images are comprised of multiple layers and each layer is an image of its own they comprise of a base image layer which is read-only any changes made to an image or saved as layers on top of the base image layer the containers are generated by running the entire set of image layers which are stacked one above the other for the demonstration purpose I'm going to show you how to run a tomcat and since on your local system I will be considering this Tomcat in an ubuntu village to build an image we have a docker file the dock file is used to install applications and build new images the daka files contain instructions for building a docker image these instructions contain various keywords like from run and many more from indicates the base image from which the container is build and run indicates the command that needs to be executed on that image for the demonstration purpose I am going to show you how to run a tomcat instance on your local system I will be configuring Tomcat and Ubuntu image to build Tomcat and one to image we use docker file the documents contain instructions for building and docker image these instructions contain various keywords like from run and many more from indicates the base image from which the container is built and run indicates the command that needs to be executed on that image let me now show you the docker file that I've created for the demonstration purpose my dacha file is present in my demos folder so let me first clear the screen and go to the demos folder I'll do a G edit docker file from a bun to indicate that I wish to use a boon to run my base image Tomcat will only run if I have Java present so I need to make sure to install both Java and Tomcat and my ubuntu village and as you can see there are three run commands my first run command is to add a Java repository my second run command is to install Java and my third run command is going to install my Tomcat this is the command to add a Java repository along with this I will run apt-get update command first and then installed coal I installed coal because later on I will be using curl to download the tar file of Tomcat these are the commands that will manage the repositories from where we install the software and this command is used to create the Java repository now to install Java this is the command used and these are the other licenses which are involved to install Java so the third run command which will install my Tomcat will first create a directory it will create a Tomcat directory in which it's going to download the Tomcat tar file it will download the tar file using curl and dwell on tar the package using this command then I'm going to use the RM RF command the Tomcat users or XML file has the properties to manage the roles in the Tomcat so this command is going to copy the properties in this file to this particular location let me show you the properties in this file as you can see these are the properties to set the roles these are the different roles manager GUI manager script manager JMX manager status admin GUI and admin script I am assigning the same username and password to all the roles in this line as you can see I am separating all the roles by a comma manager GUI is one manager script manager JMX these are the different roles and I'm separating them with a comma and I am assigning the password at Rekha and the username at breaker to them so the next command in my daugher file is the expose command expose is used to ask Tomcat to run on the 8080 Porter after that I set my environment variables for Java then I have the CMD command the CMD command specifies the entry point in a docker file I use the CMD command to start the Catalina or shell file in the bin folder by specifying run now that my docker file is ready let me build my docker image let me go to my terminal I'm going to clear the screen the command to build the docker images docker build - T and the image name colon tag and I give a dot specifying that my TOC file is present in this folder my demos folder enter as you can see the base image that is being used is Ubuntu and it's pulling all the layers this is going to take some time so my first pull is complete now it's running the applicate update and it's going to install my call okay the first run is complete and now is the third run my third run my java is being installed so my fourth command is running now this is where my Tomcat is installed as you can see my image has been successfully built now I can run my image the command to run my images docker on I'll give a - p li 0 e 0 : a throw a 0 this is to map my container port to my host port folks do note that I have used a - P flag here where the P is lowercase now only if I am using a lowercase P flag well I have to mention the host port on which I want the instance to run whereas if I use an uppercase P flag then the command will run the default host port to which the container has been mapped and then I'll just give it a name but then and the container name as you can see my server is up and running if I open it in a new terminal if I do a docker PS command you can see there is one container that's up and running the Catalina shell is running and it's active on this port of mine so I'm going to copy this I am go to my web browser and paste it here now if I go here I would find my Tomcat is configured as you can see my Tomcat is configured let me go to manager app and all my roles are visible here so folks this shows a tomcat has been successfully configured I downloaded one to image and I installed Tomcat on that and I created a new image and I created a container out of the new image so this is the ID of the container and this is the name of the image we can just start uh pstop containers by just running a command from the terminal we need to specify the container ID as a parameters to to swap a container I can just give a docker stop and the container ID or the container name and if I want to remove the container altogether then I can do a docker RM and the container name or the container ID to delete an image I can do a docker RMI and the image ID but do remember that I cannot remove a running container so I need to first top the container and then give the RM command to remove the docker container let me show you that in my terminal this is the ID of my running container I'm going to copy this I am going to do a docker stop so this is going to stop my Tomcat yeah now if I go here you can see my container has been stopped and have exited that container now let me do a dock of PS command as you can see there are no containers running if I do a docker PS - eh it will show all my containers which are exited so I have a HelloWorld command and a tomcat container which I created so I can delete these containers by giving the docker RM and the container ID copy this and paste it here so that's remote in the same way I'm going to copy this do a docker RM and paste the container ID here and I'm going to remove so now if I do a docker PS - eh I am NOT going to find those containers similarly my docker images are here I can also remove my docker images by giving the docker RMI and continued right and image ID let's revise some important topics around docker functionality that we learned earlier the docker daemon is the process which runs on the host machine it manages different docker objects like images containers networks volumes data etc the docker client is the command-line interface using which the users will communicate with the docker demon for managing various objects like the images and containers the docker images are the read-only templates which are used to create the docker containers the docker image is an executable file built by packaging all the application and the features the docker registries are where the images are stored you can store the images in your local repository or in the docker hub which this dock was very own cloud repository containers are the run component of docker and the actual running instances of images okay folks that is the end of our session and these are the topics that we cover today first I told you the difference between containerization and virtualization then I spoke about docker and then I told the difference between docker containers and virtual machines I then told you what is Dockers role and DevOps and I spoke about docker engine I spoke about docker images containers and registry and finally I finished the session by talking about Dockers working architecture then I also showed you hands-on where I told you how to build your own docker images and it's been continuous all of them ok folks these are further questions that can test your learning please take your time to understand the questions and then answer them you can put the answers in the comment box and I will validate your answer you can also comment your doubts and queries to which I would respond add the earliest I hope this video helped you understand some important concepts around docker if you are interested to learn more about docker you can check out our DevOps course at www.archives.gov/calendar in our channel to learn more happy learning you

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Keywords: yt:cc=on, docker tutorial for beginners, Docker tutorial, What is Docker, Docker, docker beginner tutorial, docker training video, docker container, Docker Training, devops docker, docker basics, containerization docker, what is docker container, Docker Introduction, docker swarm, docker compose, Docker Architecture, docker explained, introduction to docker, how to use docker, DevOps tools, learn docker, Docker vs VM, devops training, docker edureka, edureka, devops edureka

Id: h0NCZbHjIpY

Length: 31min 34sec (1894 seconds)

Published: Tue Oct 04 2016