I am working on terraform tasks and trying to understand how state files work. I have created main.tf file which has
vpc,firewall,subnet,compute_instance
which has to be create in GCP. So i have applied this to GCP environment and a file name terraform.tfstate file got created and i did backup of this file into folder called 1st-run.
Now i have updated my main.tf with
2vpc,2firewalls,2subnets,compute_instance
as i need to add another nic for my vm.Did terraform apply and environment got created and terraform.tfstate file got created. I did backup of this file into folder called 2nd-run.
I want to rollback the environment where i have executed for 1st-run. I have that state file which is in 1st-run folder.
What is the command to rollback by using statefile instead of touching the code so that automatically my GCP environment will have
vpc,firewall,subnet,compute_instance
which i have executed for the 1st time.
There is no way to roll back to a previous state as described in a state file in Terraform today. Terraform always plans changes with the goal of moving from the prior state (the latest state snapshot) to the goal state represented by the configuration. Terraform also uses the configuration for information that is not tracked in the state, such as the provider configurations.
The usual way to represent "rolling back" in Terraform is to put your configuration in version control and commit before each change, and then you can use your version control system's features to revert to an older configuration if needed.
Not all changes can be rolled back purely by reverting a VCS change though. For example, if you added a new provider block and resources for that provider all in one commit and then applied the result, in order to roll back you'd need to change the configuration to still include the provider block but not include any of the resource blocks, so you'd need to adjust the configuration during the revert. Terraform will then use the remaining provider block to configure the provider to run the destroy actions, after which you can finally remove the provider block too.