day36.md

On the thirty sixth day, I learned the following things about Terraform.

Terraform Configurations in JSON Format

• First create a directory by the name of hello-world-json.

• Get into it by writing cd hello-world-json and create a file by the name of first.tf.json in it.

• Inside that file, write the following data in the JSON format.

  {
          "output": {
                  "hello": {
                          "value": "Hello Bilal, nice meeting you."
                  }
          }
  }
  

• After writing and saving the data, write a command terraform plan and it will show the keys and values as a result that you have written in a file.

• Terraform also works with the JSON format to write the infrastructure.

Write Multiple Blocks in Single Terraform File

• Create a directory by the name of hello-world-multi-block.

• Get into it by writing cd hello-world-multi-block and create a file by the name of first.tf in it.

• Inside the first.tf file, write the following data.

  output "firstoutputblock" {
          value = "this is the first hello world block"
  }
  
  output "secondoutputblock" {
          value = "this is the second hello world block"
  }
  
  output "thirdoutputblock" {
          value = "this is the third hello world block"
  }
  

• After writing and saving the data, write a command terraform plan and it will show the keys and values as a result that you have written in a file.

Write Multiple Terraform files in the Same Directory

• Create a directory by the name of hello-world-file-destructure.

• Get into it by writing cd hello-world-file-destructure and create a file by the name of first.tf in it.

• Inside the first.tf file, write the following data.

  output "firstoutputblock" {
          value = "this is the first hello world block"
  }
  

• Create another file by the name of second.tf and write the following data in it.

  output "secondoutputblock" {
          value = "this is the second hello world block"
  }
  

• Create another file by the name of third.tf and write the following data in it.

  output "thirdoutputblock" {
          value = "this is the third hello world block"
  }
  

• After writing and saving the data, write a command terraform plan and it will show the keys and values as a result that you have written in the files.

• The result will be loaded in an alphabetical sequence according to the given output.

Create a variable in a file

• Create a directory by the name of hello-variable and get into by writing cd hello-variable.

• After that, create a file by the name of hello-variable.tf and write the following data into it.

  variable username {}
  
  output printname {
        value = var.username
  }
  

• After writing and saving the data, write a command terraform plan and it will ask you for the username and then show the keys and values as a result that you have written in a file.

• If you want to write something more with the user name then write it inside the commas like this:

  variable username {}
  
  output printname {
        value = "Hello, ${var.username}"
  }
  

• After writing and saving the data, write a command terraform plan and it will ask you for the username and then show the keys and values as a result that you have written in a file.

• Now separate the variables and the outputs in different files by simply creating another file by the name of variable.tf inside the hello-variable directory.

• Cut the variable username {} from the hello-variable.tf and paste it in a newly created file variable.tf.

• After writing and saving the data, write a command terraform plan and it will ask you for the username and then show the keys and values as a result that you have written in a file.

Enter a variable value in the command

• We have seen that in order to enter the username, you first have to write terraform plan and then it will ask you for the value to be printed.

• But you can give a value in the command also by simply writing terraform plan -var "username=Bilal Khan" and it will print the data for you without asking to enter the value.

Explaining it in a video

Here you can get an explanation in a video. 36/60 Day of DevOps Challenge