I set up terraform to use a backend to remotely store the statefile. That works fine.
My project take several minutes for the full terraform apply to complete. During development, sometimes one of the later stages hangs (seemingly) eternally. I need the outputs in order to manually connect to the servers and inspect what is broken. However, the statefile does not get written until the terraform process completes. So there are no outputs available during the first terraform apply.
Is there a way to make terraform update the statefile intermediately, while it is still busy applying things?
I know I could solve this by separating the process into multiple modules, and apply each one after the other. But I am looking for a solution where I can still apply all at once.
When you run
terraform plan
you get the outputs also. What you can do is save that file before applying -
terraform plan -out tf.plan
Then you apply.
You can look into this file to find the changes.
Remember, you won't find the output data that were to be showed after apply, like a thing that does not exist yet.
Best wishes.
So here's what I'm trying to do
Given I changed a configuration in the load balancer
And I added that to my terraform declaration
When I run a plan there are zero changes which is expected
Do I need to refresh at this point to match my hardware state before applying?
Or when I run an apply this would just update the state?
If you've changed the settings outside of Terraform and you've updated the Terraform configuration to match then indeed there's no extra step to run here: terraform plan should report that it detected the value changed outside of Terraform (assuming you're using Terraform v1.0.0 or later) but then report that it doesn't need to make any changes to match with the configuration.
Note also that in recent Terraform the terraform refresh command is still available but no longer recommended. Instead, you can use terraform apply -refresh-only to get a similar effect but with the opportunity to review the detected changes before creating a new state snapshot. In the situation you've described, a refresh-only apply like this will also allow you to commit the detected change as a new state snapshot so that future terraform plan won't re-report that it detected a change made outside of Terraform, which might avoid your coworkers being confused by this message when they make a later change.
I'm new to this terraform world and I've been assigned into the task of creating many configurations to azure with it.
I'm developing a main.tf script (which creates some resources, like resource group, vnets, kubernetes cluster, app services, etc.) and while coding it and executing
Terraform apply, it seems to only apply what changed doing in fact updates.
Then we deleted the resource group the script created and a colegue of mine had to run the same script with terraform creating a resource group with another name since i didn't had a required permission, after that, if i run the command Terraform apply it fails and gives errors, that say that the resource cannot be created because it already exists.
After reading some documentation i found that it might be because of the state
https://www.terraform.io/docs/state/index.html
Is the update of a script something that only works for each session of terraform?
Even doing a Terraform refresh doesn't seem to work.
Or probably I'm just mistaking and there is no way to update some resources.
EDIT: for some reason the state file that was on the storage only had a few things, the solution was to delete everything and create again.
For the new resources, there is nothing more, the Terraform script helps you create the resources you set in the script.
For the existing resources, when you make changes in the script that you already deployed via the Terraform, then it will check the state file to make sure what changes the resources should update. If there is no state file ( or you delete it), then it will deploy the Terraform script directly, but if any resources you want to deploy already exists, then it will fail due to the existing resources. And the command terraform refresh just updates the last state of the resources in the Terraform script that you already deployed. If the deployment failed and the state file has no resources in it, then refresh is not useful.
If someone else ran terraform apply for you because you didn't have access, and now you want to modify that terraform and run it yourself, you need to get the state file that was generated when that other person ran it. You absolutely have to maintain the Terraform state file somewhere, so that it can be accessed on subsequent runs. You should really configure a Terraform backend, instead of using local state files.
You need to be aware that Terraform stores everything it does in the state file, and refers to that file before every run. A terraform refresh only tells Terraform to refresh the state of the things that are in the state file, it doesn't rebuild the state file from scratch. Understanding Terraform state files is so fundamental to the use of Terraform that you really need to understand this before using it.
I make test with Terratest but I set wrong timeout and now test failed and resources are still there. I can remove them manually but better way will be using terraform destroy.
Is there way how get state or save them during running test via Terratest?
Terratest essentially just runs terraform commands with the parameters you give it in your local folder structure.
So, you should just be able to change directories to the module run by terratest (i.e. the TerraformDir) and run typical terraform commands (e.g. terraform plan, terraform destroy).
If you're asking about having the terratest do the destroy automatically for you, you can do that by passing along the same options to terraform.Destroy as in this example. The defer is recommended so that destruction happens after you have validated your resources.
I had the same problem. But in the output, it tells you the temporary folder where it's putting everything to run. It also had the state file. I was able to run a terraform destroy from that temp folder!
We have a couple approaches to tackle this issue:
Increase the Go test timeout by adding flag go test -timeout 1h
Increase the task and job timeout in the pipeline.
Use the test_structure "framework" from TerraTest with skippable Stages (env SKIP_<name of stage>). With the test_structure you can defer the destroy and will *always run.
Custom post cleanup script step in the build that run always, unless the destroy is skipped. The custom script will reset peerings, private endpoints and even clear state files.
*Not always, in case of a bigger issue, a timeout for example.
Is terraform destroy needed before terraform apply? If not, what is a workflow you follow when updating existing infrastructure and how do you decide if destroy is needed?
That would be pretty non-standard, in my opinion. Terraform destroy is only used in cases where you want to completely wipe your infrastructure. One of the biggest features of terraform is that it can do an intelligent delta of your desired infrastructure and your existing infrastructure and only make the changes needed. By performing a refresh, plan and apply you can ensure that terraform:
refresh - Has an up-to-date understanding of your current infrastructure. This is important in case anything was changed manually, outside of your terraform script.
plan - Prepares a list for you to review of what terraform intends to modify, or delete (or leave alone).
apply - Performs the changes laid out in the plan.
By executing these 3 commands in sequence terraform will only perform the changes necessary, in the order required, to bring your environments in line with any changes to your terraform file.
Where I find destroy to be useful is in non-production environments or in cases where you are performing a restructure that's so invasive that starting from scratch would ensure a safer build.
*There are also edge cases where terraform may fail to understand the correct order of operations (do I modify a security group first or a security group rule?), or it will find itself in a dependency cycle and will be unable to perform an operation. In those cases, however, running destroy is a nuclear solution. In general, I would perform the problem change manually (via command line, or AWS Console, if I'm in AWS), to nudge it along and then run a refresh, plan, apply sequence to get back on track.
No terraform destroy is not needed before terraform apply.
Your Terraform configuration (*.tf and *.tfvars files) describes the desired state of your infrastructure. It says "this is how I want my infrastructure to be."
You use the terraform tool to plan and apply changes to get your infrastructure into the desired state you have described. You can make those changes incrementally without destroying anything.
A typical workflow might be:
make changes to .tf and .tfvars files
refresh state
plan changes
review the planned changes
apply those changes
If you wanted to completely destroy that infrastructure you'd use terraform plan -destroy to see what Terraform intends to destroy. If you are happy with that you'd then use terraform destroy to destroy it.
Typically, destroy is rarely used, unless you are provisioning infrastructure for a temporary purpose (e.g., builds) or testing your ability to provision from a clean slate with different parameters. Even then, you could use a count parameter on resources to temporarily provision resources by increasing the count, then decreasing it again when no longer needed.
More comments after #mwielbut's answer.
Instead of option apply + destroy, you need to run terraform with option taint + apply
Normally we don't need run terraform destroy at all. It is a really dangerous option, especially for a production environment.
with option plan and apply, it is good enough to update the infrastructure with code.
But if you do need to destroy some resources and re-build something which is already created, you can use the option of taint, which is the right answer for your question, it is so important and missed in #mwielbut's answer.
The terraform taint command manually marks a Terraform-managed resource as tainted, forcing it to be destroyed and recreated on the next apply.
This command will not modify infrastructure but does modify the state file in order to mark a resource as tainted. Once a resource is marked as tainted, the next plan will show that the resource will be destroyed and recreated and the next apply will implement this change.
Refer:
command taint:
https://www.terraform.io/docs/commands/taint.html
a sample of option taint:
https://www.terraform.io/docs/modules/usage.html
Terraform destroy destroys all the resources and it is not required if you want to apply incremental changes. Destroy should be only used if you want to destroy the whole infrastructure.
No need to use the destroy command before apply. as long as you are in testing period you can use destroy command or destroy the complete infra you can use destroy command
You can use below flow
terraform init
terraform plan
terraform apply
if you made any manual changes that needs to update in your state file, use below command to update the state file.
Terrafrom refresh
You don't need to run to terraform destroy . If you have made any changes to you infrastructure, [added/ removed a resource], on next terraform plan & terraform apply, the changes will be reflected automatically
Terraform apply always refreshes the Terraform state, so if you change anything, it auto recognizes the changes, lets say you've updated your NSG rules, added new VM, deleted old VM, so when you run terraform apply again, your old state gets updated with the new state where you've Added/Updated/Deleted.
If you use terraform destroy, it just kills the entire state and you'll be back to the new state if you are running terraform apply.
You need to use terraform destroy only if you think you just want to bring down your infrastructure and you don't really need it.
For minor - major changes like Adding Components, Updating Rules, Deleting other things, you can use plan and apply without any problem.
Simply NO.
You don't need to run terraform apply before terraform destroyو Your terraform (.tf) files describe the state of your infrastructure.
terraform apply always refresh your infrastructure. And it identifies the state of infrastructure and updates it.
terraform destroy only use is to bring down and completely wipe down your infrastructure. (You have to think twice before using it) you can use terraform plan and terraform refresh to ensure the state of the infrastructure.
You could always manually destroy your instances, after only running your terraform apply. Then when you run terraform apply it will create brand new instances without the terraform destroy.
No! you don't need to run terraform destroy when you need a modification of resources! This is the beauty of Infra-as-Code.
Here are some more details on Terraform init, plan, apply and destroy -
terraform init command is used to initialize a working directory containing Terraform configuration files. This is the first command that should be run after writing a new Terraform configuration or cloning an existing one from version control. It is safe to run this command multiple times.
terraform plan command creates an execution plan. By default, creating a plan consists of:
a) Reading the current state of any already-existing remote objects to make sure that the Terraform state is up-to-date.
b) Comparing the current configuration to the prior state and noting any differences.
c) Proposing a set of change actions that should, if applied, make the remote objects match the configuration.
terraform apply command executes the actions proposed in a Terraform plan. (you can do an apply without plan however it's not a best practice)
terraform destroy command is a convenient way to destroy all remote objects managed by a particular Terraform configuration.
Core Terraform workflows:
The core Terraform workflow has five steps:
Write - Author infrastructure as code.
Terraform init - it’ll automatically download and install partner and community provider directly to the local disk so that it can be used by other commands Plugin_Installation, Backend_Initialization, ChildModule_Installation and Community and third party plugin
Terraform plan - Preview changes before applying.
Terraform Apply - Provision reproducible infrastructure.
Terraform destroy - It will destroy your infrastructure.
No need for terraform destroy, as it will just destroy all the resources created.
You just need to provide the backend configuration in your tf file.
Backend configuration is the configuration in order to retrieve terraform state files.
Terraform apply first time will create your cloud infrastructure, this will update your state file also.
And next apply terraform will compare what new/update resources are to be done with what is already there using state file and will deploy accordingly.