How to remove a resource from Terraform state?

To remove a resource from the Terraform state, you can use the $ terraform state rm command. This command allows you to remove resources from the Terraform state file.

1. How to remove a single resource from terraform state file?

Here are the steps which you should follow before you remove any resource -

1. List the resource- Using the following terraform list resource command first you can check how many resources you are planning to remove from the state file.

1# List all the resources
2
3terraform state list 

2. Remove the resource - If you want to remove a resource named my_resource from the state, you can use the following command:

1# Remove the resource name - my_resource  
2
3terraform state rm my_resource

3. $terraform apply - Previous command will remove the resource and all of its associated data from the state file. You can then use the $terraform apply command to apply the changes and remove the resource from your infrastructure.

It's important to note that removing a resource from the Terraform state does not destroy the resource itself. If you want to destroy the resource and remove it from your infrastructure, you will need to use the $terraform destroy command.

2. How to remove multiple resources from terraform state file?

There is no out-of-the-box support for removing multiple resources from the state file. But you can be a little smart with you shell scripting skills and can build short custom commands to remove multiple resources from the state file.

Here is my first example -

1# Instead of aws_instance, you can supply your own resource name  
2
3terraform state rm $(terraform state list | grep aws_instance)

Here is my second example -

1# Remove multiple resources without locking the state between each resource
2
3terraform state list | cut -f 1 -d '[' | xargs -L 1 terraform state rm 

3. How to remove the s3 bucket/ec2 instance from the terrafrom state file?

If you want to remove an S3 bucket named my-bucket from the state, you can use the following command:

1# Remove S3 bucket from state file
2# Replace the my_bucket name with the correct bucket name.
3
4 terraform state rm aws_s3_bucket.my-bucket

1# Remove EC2 instance from the state file
2# Replace the my_bucket name with correct EC2 instance name.
3
4 terraform state rm aws_instance.my-instance

This will remove the S3 bucket and all of its associated data from the state file. You can then use the terraform apply command to apply the changes and remove the bucket from your infrastructure.

It's important to note that removing an S3 bucket from the Terraform state does not delete the bucket itself.

4. How to save the backup of terraform state file while using terraform state rm?

To use the $ terraform state rm command with the -backup flag, you can specify the path where you want to save a backup of the state file before the changes are applied.

Here is an example of using the $ terraform state rm command with the -backup flag to remove an EC2 instance from the state and save a backup of the state file:

1# Specify the path to the backup state file before removing the resource
2
3terraform state rm -backup=./state_backups/aws_instance.my-instance aws_instance.my-instance
4 

In this example, the EC2 instance named my-instance will be removed from the state file, and a backup of the state file will be saved to the ./state_backups/ directory with the name aws_instance.my-instance.

You can use the -backup flag to save a backup of the state file before making any changes, in case you need to restore the state later on.

For more information about the terraform state rm command and how to use it, you can refer to the Terraform documentation

5. Use -path flag to specify the path of the state file to modify the resource

To use the $ terraform state rm command with the -state flag, you can specify the path to the state file that you want to modify.

Here is an example of using the $ terraform state rm command with the -state flag to remove an EC2 instance from a state file located in a different directory:

1# Here you can specify the state file that you want to modify
2
3terraform state rm -state=./my-project/terraform.tfstate aws_instance.my-instance

In this example, the EC2 instance named my-instance will be removed from the state file located at ./my-project/terraform.tfstate.