provider “aws” {region = “ap-south-1”access_key = “”secret_key = “”} provider “github” {token = “”organization = “”} variable “instance_count” {type = numberdescription = “This is for demo of number variable”default = 2 }variable “users” {type = “list”default = [“bharath”, “sharath”, “nikhil”]description = “This is for demo of list variable”} variable “amis” {type = “map”default = {“us-east-1” = “ami-““us-west-2” = “ami-“}} variable “reponame” {type = stringdescription = “This is for demo of string variable”default = “terraform”} resource “aws_iam_user” “iamuser” {name = “${var.users[0]}”}

provider “aws” {access_key = “”secret_key = “”region = “eu-east-2”} resource “aws_instance” “web” {ami = “ami-xbbsj”instance_type = “t2.micro”count = 1tags = {Name = “Demo”}} provisioner “file” {source = “conf/install-apache.yml”destination = “/etc/install-apache.yml”} provisioner “remote-exec” {inline = [“sudo apt update”, “sudo apt install python3 -y”, “sudo apt install ansible -y”] } provisioner “local-exec” {command = “ANSIBLE_HOST_KEY_CHECKING=False ansible-playbook -u root -i ‘${self.ipv4_address},’ –private-key ${var.pvt_key} -e ‘pub_key=${var.pub_key}’ install-apache.yml”} } install-apache.yml -name=install_httpdhosts=webservertasks=-name:install httpd in serveryum:name: httpdstate: latest

CMD You can set default commands with parameters using the CMD instruction. If you run a Docker container without specifying any additional CLI commands, the CMD instruction will be executed. You can include an executable as the default command. However, if you choose to omit it, you will have to specify an ENTRYPOINT instruction along with the CMD instruction. If you have specified an argument along with the Docker run command, the default one specified using the CMD instruction will

Ansible playbook demo.yaml -name= install nginxhosts= webservertasks=-name: install nginx in serveryum:name: httpdstate: latest Terraform script to insstall ansible and python provider “aws” {access_key = “*******************”secret_key = “*********************”region = “eu-west-3”} resource “aws_instance” “web” {ami = “ami-12345”instance_type = “t3.micro”count = 1tags = {Name = “Demo”}} provisioner “file” {source = “etc/demo.yaml” destination = “etc/demo.yaml”} provisioner “remote-exec” {inline = [“sudo apt update”, “sudo apt install python3 -y”, “sudo apt install ansible -y”] connection {host = self.ipv4_addresstype = “ssh”user = “root”private_key = file(var.pvt_key)} } provisioner

provider “aws” {access_key = “************”secret_key = “************”region = “eu-west-3”} provider “github” {token = “*************”} variable “instance_count” {type = numberdescription = “This is for demo of number variable”default = 3} variable “reponame” {type = stringdescription = “This is for demo of string variable”default = “day3-broad”} variable “users” {type = “list”default = [“demo1”, “demo2”, “demo3”]description = “This is for demo of list variable”} variable “amis” {type = “map”default = {“us-east-1” = “ami-b374d5a5”“us-west-2” = “ami-4b32be2b”}} resource “github_repository” “repo” {name = var.reponamedescription = “Demo

FROM A FROM command allows you to create a base image such as an operating system, a programming language, etc. All the instructions executed after this command take place on this base image. It contains an image name and an optional tag name. If you already have the base image pulled previously in your local machine, it doesn’t pull a new one. There are several pre published docker base images available in the docker registry. You can also push your

docker exec The docker exec command runs a new command in a running container. docker attach The docker attach command to attach your terminal’s standard input, output, and error (or any combination of the three) to a running container using the container’s ID or name.

docker stop The docker stop command stops the container gracefully and provides a safe way out. If a docker stop command fails to terminate a process within the specified timeout, the Docker issues a kill command implicitly and immediately. In Docker, there are two ways we can use the docker stop command to stop a process. We can use container Id or container name to stop a container. docker kill The docker kill command terminates the entry point process abruptly. The docker kill command causes an unsafe exit. In some cases, the docker container

Docker pause The docker pause command suspends all processes in the specified containers. Docker unpause The docker unpause command resumes all processes in the specified containers.

The Docker components are divided into two categories; basic and advanced. The basic components include Docker client, Docker image, Docker Daemon, Docker Networking, Docker registry, and Docker container, whereas Docker Compose and Docker swarm are the advanced components of Docker.  Basic Docker Components: Lets dive into basic docker components: Docker Client: The first component of Docker is the client, which allows the users to communicate with Docker. Being a client-server architecture, Docker can connect to the host remotely and locally. As

docker pull: pull the image from the docker hubdocker ps: list the running containersdocker ps -a: list the running and stopped containersdocker start start the containerdocker stop: stop the one or more running containersdocker restart: restart the containerdocker rm: remove the containerdocker exec: runs a new command in a running containerdocker image: show all imagedocker info: show the information about docker installationdocker kill: kill one or more running containersdocker login: login into docker register

CMD: Default parameters can be override from the Command Line Interface when container is runningENTRYPOINT: Default parameters cannot be override from the Command Line Interface when Container running

FROM: specify the valid docker image name, LABEL: metadata infomation to the image, ADD: copy files, directories and remote URL files to the destination, RUN: executes any command, WORKDIR: set the working directory, ENV: set environment variables with key and value, COPY: copy files, directories and remote URL files to the destination, MAINTAINER: author who create the docker image

Docker follows Client-Server architecture. Docker having three main components Docker Client, Docker Host, and Docker Registry.Docker Client: Docker client uses REST APIs to communicate with the Docker server when the client send commands to the server, server receives commands in the form of REST APIs request.Docker Host: Docker Host is used to provide an environment to execute and run applications. It contains the docker daemon, images, containers, networks, and storage.Docker Registry: Docker Registry manages and stores the docker images

docker exec executes a new command or create a new process in the container. while docker attach just connects the standard input or output or error to a running container using the container ID or name

docker info: displays information about docker installation docker ps : to check the running containers docker ps -a : to check all the containers which are running and exited docker images: to check the list of images docker pull: to pull the image from registry docker push: to push the created image to registry docker stop: to stop the container docker start: to start the stopped container docker kill: to kill the running container unsafe docker rmi: to remove the

both the commands are when we run container using images. ENTRY POINT appends the commands given in command line CMD overrides the command given in command line

Stop: The docker stop command stop one or more running containers, By sending “SIGTERM” signal inside the container and stop the processKill: The docker kill command kill one or more running containers, By sending “SIGKILL” signal inside the container and kill the process immediately

FROM : To get the base image MAINTAINER: author of the generated image ADD: It is similar to COPY but it supports get remote URLs and also unzips tar balls RUN: Run is used to run specific commands. CMD: This is similar to ENTRYPOINT it allows the override the command ENTRYPOINT: after starting the container it is the initial process that runs. Entry point doesn’t allow override the command WORKDIR: Used to create working directory inside the container. COPY: copy

Pause: The docker pause command suspends all processes in the specified containers. when suspending a process the SIGSTOP signal is used, which is observable by the process being suspendedUnpause: The docker unpause command unsuspends all processes in the specified containers.