JSON configuration alternative in Terraform - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a JSON variable in Terraform.

Terraform

variable "config" {
  type = [1]
}

Drag options to blanks, or click blank then click option'

Aany

Bstring

Cmap(string)

Dobject

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'string' type instead of 'map(string)'

Using 'any' which is too broad for this case

The map(string) type is used to represent JSON objects with string values in Terraform.

2fill in blank

medium

Complete the code to parse a JSON string into a Terraform map.

Terraform

locals {
  config_map = jsondecode([1])
}

Drag options to blanks, or click blank then click option'

Avar.config

Bjson

Cconfig

D"var.config"

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the variable name as a string with quotes

Passing an undefined variable

The jsondecode() function expects a JSON string variable, so we pass var.config without quotes.

3fill in blank

hard

Fix the error in the JSON configuration by completing the code.

Terraform

resource "aws_s3_bucket" "example" {
  bucket = [1]
  acl    = "private"
}

Drag options to blanks, or click blank then click option'

Abucket_name

Bjsondecode(var.bucket_name)

C"var.bucket_name"

Dvar.bucket_name

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the variable name

Using jsondecode on a string variable

The bucket name should be passed as a variable reference var.bucket_name without quotes or decoding.

4fill in blank

hard

Fill both blanks to create a JSON object variable and assign a default value.

Terraform

variable "settings" {
  type    = [1]
  default = [2]
}

Drag options to blanks, or click blank then click option'

Amap(string)

Bobject({region=string, env=string})

C{"region" = "us-east-1", "env" = "dev"}

D{region = "us-east-1", env = "dev"}

Attempts:

3 left

💡 Hint

Common Mistakes

Using JSON string syntax for default value

Using map(string) type without specifying keys

The variable type is an object with keys and string types, and the default value is a Terraform map with key-value pairs.

5fill in blank

hard

Complete the code to decode a JSON string and access a nested value.

Terraform

locals {
  config = jsondecode([1])
  region = config["region"]
}

Drag options to blanks, or click blank then click option'

Avar.json_string

B[

C]

D.

Attempts:

3 left

💡 Hint

Common Mistakes

Using dot notation for map access

Passing JSON string as a literal with quotes

We decode the JSON string variable, then access the 'region' key using square brackets.

Practice

1. What is the main reason to use JSON configuration files in Terraform instead of the usual HCL language?

easy

A. To enable automation and integration with other tools

B. Because JSON files are easier to read for humans

C. To reduce the size of the configuration files

D. Because Terraform does not support HCL anymore

Solution

1. Step 1: Understand Terraform configuration formats

   Terraform supports both HCL and JSON formats for configuration files.

2. Step 2: Identify the benefit of JSON format

   JSON is often used for automation and integration with other tools because it is a widely supported data format.

3. Final Answer:

   To enable automation and integration with other tools -> Option A

4. Quick Check:

   JSON helps automation = C [OK]

Hint: JSON is best for automation and tool integration [OK]

Common Mistakes:

• Thinking JSON is easier for humans to read than HCL
• Believing Terraform no longer supports HCL
• Assuming JSON reduces file size

2. Which of the following is the correct way to start a Terraform JSON configuration file?

easy

A. { "resource": { "aws_instance": { "example": { "ami": "ami-123456", "instance_type": "t2.micro" } } } }

B. { resource: { aws_instance: { example: { ami: "ami-123456", instance_type: "t2.micro" } } } }

C. { "resource": [ { "aws_instance": { "example": { "ami": "ami-123456", "instance_type": "t2.micro" } } } ] }

D. [ "resource": { "aws_instance": { "example": { "ami": "ami-123456", "instance_type": "t2.micro" } } } ]

Solution

1. Step 1: Check JSON syntax rules

   JSON keys and strings must be in double quotes, and objects use curly braces {}.

2. Step 2: Identify correct Terraform JSON structure

   Terraform expects "resource" as a key with nested objects, not arrays or unquoted keys.

3. Final Answer:

   { "resource": { "aws_instance": { "example": { "ami": "ami-123456", "instance_type": "t2.micro" } } } } -> Option A

4. Quick Check:

   Proper JSON syntax with quoted keys = A [OK]

Hint: Always use double quotes for keys and strings in JSON [OK]

Common Mistakes:

• Using unquoted keys in JSON
• Using arrays instead of objects for resources
• Mixing JSON and HCL syntax

3. Given this Terraform JSON snippet:

{
  "variable": {
    "region": {
      "default": "us-west-2"
    }
  },
  "provider": {
    "aws": {
      "region": "${var.region}"
    }
  }
}

What will happen when you run terraform apply?

medium

A. Terraform will deploy resources in the us-west-2 region

B. Terraform will throw an error because variable interpolation is not supported in JSON

C. Terraform will ignore the provider region and use the default AWS region

D. Terraform will deploy resources but with an empty region value

Solution

1. Step 1: Understand variable interpolation in Terraform JSON

   Terraform JSON does not support interpolation syntax like "${var.region}" inside JSON files.

2. Step 2: Identify the error cause

   Using interpolation in JSON causes Terraform to fail parsing or applying the configuration.

3. Final Answer:

   Terraform will throw an error because variable interpolation is not supported in JSON -> Option B

4. Quick Check:

   Interpolation not allowed in JSON = A [OK]

Hint: No interpolation syntax allowed in Terraform JSON files [OK]

Common Mistakes:

• Assuming interpolation works same as HCL
• Thinking Terraform ignores invalid region values
• Believing Terraform defaults region silently

4. You have this JSON Terraform config snippet:

{
  "resource": {
    "aws_instance": {
      "ami": "ami-123456",
      "instance_type": "t2.micro",
      "tags": {
        "Name": "ExampleInstance"
      }
    }
  }
}

When running terraform apply, you get a syntax error. What is the most likely cause?

medium

A. The JSON keys are not properly quoted

B. The "tags" block should be an array, not an object

C. The JSON file is missing a root-level "terraform" key

D. The JSON file uses incorrect nesting for resource blocks

Solution

1. Step 1: Review Terraform JSON resource structure

   Terraform expects resource blocks nested as: resource type -> resource name -> attributes.

2. Step 2: Check the nesting in the snippet

   The snippet places attributes directly under the resource type "aws_instance" without the required instance name (e.g., "example") as an intermediate object key.

3. Final Answer:

   The JSON file uses incorrect nesting for resource blocks -> Option D

4. Quick Check:

   Resource nesting must follow Terraform JSON schema = B [OK]

Hint: Check resource nesting carefully in JSON configs [OK]

Common Mistakes:

• Confusing JSON object vs array for tags
• Expecting a "terraform" root key in JSON
• Not quoting JSON keys properly

5. You want to convert this HCL Terraform config to JSON:

resource "aws_s3_bucket" "bucket" {
  bucket = "my-bucket"
  acl    = "private"
  tags = {
    Environment = "Dev"
    Team        = "Cloud"
  }
}

Which JSON configuration correctly represents this resource?

hard

A. {
"resource": {
"aws_s3_bucket": {
"bucket": "my-bucket",
"acl": "private",
"tags": {
"Environment": "Dev",
"Team": "Cloud"
}
}
}
}

B. {
"resource": [
{
"aws_s3_bucket": {
"bucket": {
"bucket": "my-bucket",
"acl": "private",
"tags": {
"Environment": "Dev",
"Team": "Cloud"
}
}
}
}
]
}

C. {
"resource": {
"aws_s3_bucket": {
"bucket": {
"bucket": "my-bucket",
"acl": "private",
"tags": {
"Environment": "Dev",
"Team": "Cloud"
}
}
}
}
}

D. {
"resources": {
"aws_s3_bucket": {
"bucket": {
"bucket": "my-bucket",
"acl": "private",
"tags": {
"Environment": "Dev",
"Team": "Cloud"
}
}
}
}
}

Solution

1. Step 1: Understand Terraform JSON resource format

   Terraform JSON uses "resource" (singular) as the root key with nested resource type and name.

2. Step 2: Compare options for correct keys and structure

   { "resource": { "aws_s3_bucket": { "bucket": { "bucket": "my-bucket", "acl": "private", "tags": { "Environment": "Dev", "Team": "Cloud" } } } } } correctly uses "resource" with nested "aws_s3_bucket" and resource name "bucket" with attributes.

3. Final Answer:

   { "resource": { "aws_s3_bucket": { "bucket": { "bucket": "my-bucket", "acl": "private", "tags": { "Environment": "Dev", "Team": "Cloud" } } } } } -> Option C

4. Quick Check:

   Correct root key and nesting = D [OK]

Hint: Use singular "resource" key with nested type and name [OK]

Common Mistakes:

• Using "resources" instead of "resource"
• Using arrays instead of objects for resources
• Incorrect nesting of resource name and attributes