Update README.md

README.md

@@ -1,5 +1,10 @@
 # Repo to learn Docker with examples. Contributions are most welcome.
 
+## If you found this repo useful, give it a STAR 🌠
+
+You can watch the video version of this repo on my youtube channel -> https://www.youtube.com/@AbhishekVeeramalla
+
+
 ## What is a container ?
 
 A container is a standard unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another. A Docker container image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries and settings.
@@ -11,6 +16,7 @@ A container is a bundle of Application, Application libraries required to run yo
 ![Screenshot 2023-02-07 at 7 18 10 PM](https://user-images.githubusercontent.com/43399466/217262726-7cabcb5b-074d-45cc-950e-84f7119e7162.png)
 
 
+
 ## Containers vs Virtual Machine 
 
 Containers and virtual machines are both technologies used to isolate applications and their dependencies, but they have some key differences:
@@ -23,6 +29,8 @@ Containers and virtual machines are both technologies used to isolate applicatio
 
    4.  Management: Managing containers is typically easier than managing VMs, as containers are designed to be lightweight and fast-moving.
 
+
+
 ## Why are containers light weight ?
 
 Containers are lightweight because they use a technology called containerization, which allows them to share the host operating system's kernel and libraries, while still providing isolation for the application and its dependencies. This results in a smaller footprint compared to traditional virtual machines, as the containers do not need to include a full operating system. Additionally, Docker containers are designed to be minimal, only including what is necessary for the application to run, further reducing their size.
@@ -36,6 +44,8 @@ Below is the screenshot of official ubuntu base image which you can use for your
 
 To provide a better picture of files and folders that containers base images have and files and folders that containers use from host operating system (not 100 percent accurate -> varies from base image to base image). Refer below.
 
+
+
 ### Files and Folders in containers base images
 
 ```
@@ -54,6 +64,8 @@ To provide a better picture of files and folders that containers base images hav
     /root: is the home directory of the root user.
 ```
 
+
+
 ### Files and Folders that containers use from host operating system
 
 ```
@@ -78,14 +90,17 @@ so, in a nutshell, container base images are typically smaller compared to VM im
 I hope it is now very clear why containers are light weight in nature.
 
 
+
 ## Docker
 
+
 ### What is Docker ?
 
 Docker is a containerization platform that provides easy way to containerize your applications, which means, using Docker you can build container images, run the images to create containers and also push these containers to container regestries such as DockerHub, Quay.io and so on.
 
 In simple words, you can understand as `containerization is a concept or technology` and `Docker Implements Containerization`.
 
+
 ### Docker Architecture ?
 
 ![image](https://user-images.githubusercontent.com/43399466/217507877-212d3a60-143a-4a1d-ab79-4bb615cb4622.png)
@@ -108,18 +123,22 @@ There are three important things,
 
 ### Understanding the terminology (Inspired from Docker Docs)
 
+
 #### Docker daemon
 
 The Docker daemon (dockerd) listens for Docker API requests and manages Docker objects such as images, containers, networks, and volumes. A daemon can also communicate with other daemons to manage Docker services.
 
+
 #### Docker client
 
 The Docker client (docker) is the primary way that many Docker users interact with Docker. When you use commands such as docker run, the client sends these commands to dockerd, which carries them out. The docker command uses the Docker API. The Docker client can communicate with more than one daemon.
 
+
 #### Docker Desktop
 
 Docker Desktop is an easy-to-install application for your Mac, Windows or Linux environment that enables you to build and share containerized applications and microservices. Docker Desktop includes the Docker daemon (dockerd), the Docker client (docker), Docker Compose, Docker Content Trust, Kubernetes, and Credential Helper. For more information, see Docker Desktop.
 
+
 #### Docker registries
 
 A Docker registry stores Docker images. Docker Hub is a public registry that anyone can use, and Docker is configured to look for images on Docker Hub by default. You can even run your own private registry.
@@ -129,10 +148,12 @@ Docker objects
 
 When you use Docker, you are creating and using images, containers, networks, volumes, plugins, and other objects. This section is a brief overview of some of those objects.
 
+
 #### Dockerfile
 
 Dockerfile is a file where you provide the steps to build your Docker Image. 
 
+
 #### Images
 
 An image is a read-only template with instructions for creating a Docker container. Often, an image is based on another image, with some additional customization. For example, you may build an image which is based on the ubuntu image, but installs the Apache web server and your application, as well as the configuration details needed to make your application run.
@@ -141,11 +162,95 @@ You might create your own images or you might only use those created by others a
 
 
 
+## INSTALL DOCKER
+
+A very detailed instructions to install Docker are provide in the below link
+
+https://docs.docker.com/get-docker/
+
+For Demo, 
+
+You can create an Ubuntu EC2 Instance on AWS and run the below commands to install docker.
+
+```
+sudo apt update
+sudo apt install docker.io -y
+```
+
+
+### Start Docker and Grant Access
+
+A very common mistake that many beginners do is, After they install docker using the sudo access, they miss the step to Start the Docker daemon and grant acess to the user they want to use to interact with docker and run docker commands.
+
+Always ensure the docker daemon is up and running.
+
+A easy way to verify your Docker installation is by running the below command
+
+```
+docker run hello-world
+```
+
+If the output says:
+
+```
+docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/create": dial unix /var/run/docker.sock: connect: permission denied.
+See 'docker run --help'.
+```
+
+This can mean two things, 
+1. Docker deamon is not running.
+2. Your user does not have access to run docker commands.
+
+
+### Start Docker daemon
+
+You use the below command to verify if the docker daemon is actually started and Active
+
+```
+sudo systemctl status docker
+```
+
+If you notice that the docker daemon is not running, you can start the daemon using the below command
+
+```
+sudo systemctl start docker
+```
+
+
+### Grant Access to your user to run docker commands
+
+To grant access to your user to run the docker command, you should add the user to the Docker Linux group. Docker group is create by default when docker is installed.
+
+```
+sudo usermod -aG docker ubuntu
+```
+
+In the above command `ubuntu` is the name of the user, you can change the username appropriately.
 
+**NOTE:** : You need to logout and login back for the changes to be reflected.
 
 
+### Docker is Installed, up and running 🥳🥳
+
+Use the same command again, to verify that docker is up and running.
+
+```
+docker run hello-world
+```
+
+Output should look like:
+
+```
+....
+....
+Hello from Docker!
+This message shows that your installation appears to be working correctly.
+...
+...
+```
 
 
+## Great Job, Now start with the examples folder to write your first Dockerfile and play with it.