Terraform if else create resource. But It says me there is no change in the infrastructure.

Terraform if else create resource I’d appreciate any advice or guidance folks could offer! Thanks in Advance! Background: Goal and Problem Goal: I am looking for a way to create a terraform resource only when a real-world resource of the same name doesn’t already exist. tfstate file. g. Read: 5 minutes. Using a loop, you can manage several similar objects without writing a separate block for each one. id value = random_string. 11 or lower? If so you should have explained that in your question because Terraform 0. If we set count = 1 for a particular resource , we will get one copy of that resource. I do not want to use taint, because we don't know when the resources is actually tainted on a run. Technical Stack: AWS, Terraform. When you use count in a resource block, that makes Terraform treat references to that resource elsewhere as producing a list of objects representing each of the instances of that resource. The If / Else statement in Terraform enables you to make decisions within your This Terraform code showcases conditional logic techniques. We can use the `aws_vpc` data $ TF_VAR_vanity_env=-np terraform apply Apply complete! Resources: 0 added, 0 changed, 0 destroyed. Terraform evaluates precondition blocks after evaluating existing count and for_each arguments. variable "create_instances" {type = bool default = false} Then run apply command as terraform apply -var="create_ebs_resource=1" if you would like to create resource else simply run terraform apply. You wouldn't normally be adding resources to "possibly" existing resource groups. Conditional resource creation or how to implement the “if else” statement in Terraform# Let’s start from the most popular one: whether to create a resource depending on some fact, e. This was introduced in Terraform 1. Modified 3 years, that block must I am trying to write an if statement in Terraform to deploy or not to deploy a specific resource and struggling to get it to work. – This is a WRONG answer. Modified 2 years, 6 months ago. foo * var. We can use the meta argument Count with conditional logic as below. Unfortunately, destroying those resources isn't an The general approach in terraform is to use resource count as an if statement to create or not the resource in that scenario. Create a terraform file named “main. The provider requires a destroy/create action if we simply declare the optional attribute and set it to null. The content there is talking about multiple modules in the same configuration, but the same principle applies to multiple configurations that interact with each other: Terraform expects that each object is managed by only one configuration, though it can It turned out that the issue is happening because of the way I was provisioning new ALB rule resources; every time I was creating TF ALB rule resource with new resource name (rule2, rule3, etc) which was clashing with existing priority number. If you create resources out of band — such as by manually clicking around the AWS Console First, create a boolean variable azurerm_create_resource_group. Note: this will also delete existing How can I incorporate this resource as being conditional? Something like if var. tf files that are generic to several applications. "resource_name": This is a user-defined name for the resource block. However, It has not created https listener yet on the infrastructure. All of the query dictionaries are nested in a list (see query_dict variable). If the data resource DOES NOT EXIST, then it is noted in the parameter and then the resource creation is skipped. password. The try function will not catch errors relating to constructs that are provably invalid even before dynamic expression evaluation, such as a malformed reference or a reference to a top-level object that has not been declared. This gives you a straightforward way to create one or more resource instances if your condition is true. This approach ensures that resources are only created when necessary, making your configuration One simple solution is: Set the variable in a suitable context, then, use in the resource name with ternary operator: "aws_lambda_function" "my_lambda". , a new instance with a different configuration in the same subnet. Terraform also evaluates preconditions before evaluating the resource's configuration arguments. tfvar files and when you run terraform just point to the var file which would be cleaner and better practice. Certain parameters should only be filled in if terraform can grab the data resource. count – This looping construct creates a fixed number of resources based on a I'd like to create the following resource only if the variable var. vms_to_image. If/Else statements are conditional statements that perform decisions based on some known state, or variable. In your case then, the answer is to ensure that the assertion that the object exists only appears in situations where it should exist. 0. – depends_on is for more complicated situations where the data flow between objects is insufficient because the final result depends on some side-effects that are implied by the remote API rather than explicit in Terraform. count is Terraform’s else {resource "aws_iam_user_policy The key realization is that terraform plan looks only at resources in its Terraform state file. 2. For example , there will be two configurations folders one for AWS and one for Azure. The lifecycle block is required. google_vpc_cidr is set not empty. Optional variable in Terraform is not ignored when the value is null. Improve this question. If Statement. As a result, neither var. This lets Terraform evaluate the precondition separately for each instance and then make each. In HCL, a boolean is one of the many ways you can create an if-statement. The following example has the effect you desire. tf line String literals are the most complex kind of literal expression in Terraform, and also the most commonly used. Just don't create a lifecycle resource for them. Anyway, for your specific case you need to combine two things: the equivalent of i of your pseudo-code in Terraform would be: count. One of the most common ways to implement if-else logic in Terraform is through conditional expressions. As an example, let’s create a “maintenance mode” for a service which allows a “under maintenance” holding page to be served when a Terraform variable is set. My customer would like to create the bit bucket pipeline which dynamically creates the s3 buckets (one at a time ). I can have it run directly from bash (which, indeed I may have to), but then I have to copy this command to every script that executes terraform, and if I have a Boolean called "loose", based on it's value I want to use an existing resource or create one, let say a security group. terraform destroy - Things will get more interesting over here because once you issue terraform destroy it will delete all terraform resources but when terraform destroy command try to evaluate the condition over the project_B it can not decide By default, a resource block configures one object. Compute resources are assigned a cost of `100`, storage resources a cost of `50`, and all other types default to a cost of `25`. variable "azurerm_create_resource_group" { type = bool } It creates those buckets too. local. In Terraform, this logic is particularly useful when fed into the countstatement to deploy multiples of resources. resource_name1 -target=resource_type2. To learn more, see Import. you can set count to 1 on a specific resource and get one copy of that resource. So if you have two boolean variables, var. Terraform If-Else Logic inside resource. My basic setup includes: terraform version However terraform tries to create all time_sleep resources in the nested module and then inerates through the objects in the main module and creates them this way: a) all time_sleep resources are created. default == 1 and another otherwise. 1_2016" ssl_support_method = "sni-only" } If not, It is intended that a Terraform configuration specifies what resources it owns, so there is no “create if not exists” operation. Certifications; Using dynamic blocks to implement a maintenance mode. The idea is to create a file that will keep count for us of who is running now and everyone else waits, I'm creating the file using a null resource: Terraform stores state which caches the known state of the world the last time Terraform ran. else: Create one aws_instance resource: If count. Dynamic resource creation; Suppose you want to create an AWS instance only when it is explicitly told to do so. It is not possible to generate meta-argument blocks such as lifecycle and provisioner blocks, since Terraform must process these before it is safe to evaluate expressions. That's Perfect Sajeer, Thanks a lot for the response For example, you could use a conditional statement to only create a resource if a certain variable is set to a specific value. 3. Goal Create two aws_athena_named_query resources using terraform. terraform apply This will validate the resources if it already exists and create if not If you are doing for different envs (e. tfvars" Terraform is declarative, not imperative. Starting in Terraform v0. . id to # get the VPC ID For more information on topics covered in this tutorial, check out the following resources: Read the Terraform custom conditions documentation. If I use count, I just need to change one variable. Where a language would write The answer by deniszh is pretty close, but I thought I'd clarify it a bit and clean up the syntax. Is there a cause of action for intentionally destroying a sand castle someone else has built on a public beach? You can use the lifecycle replace_triggered_by attribute to do this. Is there a way to detect the resource by if else select statement in Terraform, so that if the resource is exit then I I think this will be either difficult or impossible with Terraform. Indeed, that non-determinism is why you're seeing Terraform in your situation flop between trying to create and then trying to delete the resource: you've told Terraform to only manage that object if it doesn't already exist, and so the first time you run Terraform after it exists Terraform will see that the object is no longer managed and so As per my knowledge, terraform does not support direct if-else statements. We will combine this idea with the count attribtue of a resource to create an if-else statement. resource "aws_iam_user" "terraform_users" Optionally Creating Resources # The tools for optionally creating a resource block in Terraform are the count and for_each meta-arguments. key, count. You can create two resources: one if var. In your case to trigger the replace of aws_lightsail_instance_public_ports. jar" Only one of the two resources is created due to the count attribute. I populate many of the fields via a . terraform plan and to apply the tf script changes. proj_key, │ on main. internal is true and instead create a record in the public zone when var. For example, you may want to create a specific resource only if a certain condition If true, instances are created based on the length of instance_names; otherwise, no instances are created. I have tried this already but terraform does not allow having 2 data sources with the same name: A aws_vpc data resource named "vpc" was already declared. , the value of a variable. In certain scenarios, you can add depends_on to force a resource to create after another. k8s_role k8s-role If it does not exists in the path it will simply ignore the resource creation and will go ahead with the rest of the code. 12 Use-cases Example, in AWS, if a security group It is intended that a Terraform configuration specifies what resources it owns, so there is no “create if not exists” operation. Current Terraform Version 0. win_folder["the server id"]'. Publish Provider Module Policy Library Beta. Conditionally add to resource attribute via terraform. Is there a way of coding a resource that includes a for_each loop in such away that the resources only get created if a boolean variable use count to create resources in a loop. All we had to do was write a script that executed cloudtrail queries to search for all "Create" API calls made that DID NOT assume the Jenkins-Terraform role, and we got all resources that were created manually through the console by people with way too much power. 12+'s null to rewrite this more simply: A well known technique to control the conditional creation of resources is to use something like: count = var. The syntax of a conditional expression is as follows: Terraform discussion, resources, and other HashiCorp news. The from argument is the address of the resource you want to remove, without any instance keys (such as "aws_instance. But you can develop your own external data source to do that. It seems like for loops in terraform are not advanced enough to do this. The simplest expressions are just literal values, like "hello" or 5, but the Terraform language also allows more complex How can we conditionally create this module based on the return value from local. tfstate file is under workspace us-east-1. " type = string} Explanation:-local. index (in case you use count) the if-else-else is probably something like: When you use count in a resource block, that makes Terraform treat references to that resource elsewhere as producing a list of objects representing each of the instances of that resource. "). For this, I can have a variable defined like "lb_exists=true" and based on this "true" value, the resource has to be created otherwise, terraform should skip the LB creation. workspace] == "logging" ? true : false Hello - I’m working on my first terraform project and am hitting a snag. Is there a resource that can taint another resource? If I could create additional document versions, I think that would address the problem. ) - As expected. create_vm_images == "Yes" then for_each = var. The documentation doesn't include an explicit example of the equivalent pattern for count, but it I’m trying to write a module to DRY up some AWS CloudFront distributions across multiple environments. But It says me there is no change in the infrastructure. Terraform meta-argument count helps to describe that kind of resource creation logic. Let’s imagine that our myvar setting is not set to “some_setting” - well in that case, the resource group will not create; however, the app service plan will, because no such check exists. Improve this answer. That is where you use the whatever returned attributes to subsequent resources. The Terraform documentation has a section Chaining for_each between resources which describes declaring chains of resources that have the same (or derived) for_each expressions so that they can all repeat based on the same source information. myserver-sig-public-ports whenever aws_lightsail_instance. Terraform supports both a quoted syntax and a "heredoc" syntax for strings. In Terraform, a boolean true is converted to a 1 and a boolean false is converted to a 0. tfvars file. They also allow for filtering data and configuring specific resource Terraform provides a way to conditionally write resources using a ternary operator, the conditional expression is as following: condition ? value_if_true : value_if_false Using a ternary operator to Resource Creation Based on Conditions. Resource : Azure Alert (azurerm_monitor_scheduled_query_rules_alert_v2) If you found this page like me, looking to rename resources that were not created by terraform/tofu - You can find a given result by using the data block to filter a given object, and then use the aws_ec2_tag resource to apply a Name tag to the resource, assuming that the resource you are trying to modify accepts an ec2 tag. – How to write If/Else Statements in Terraform. The example below will create the null resource if the condition is true, and because two is greater than one, this will be true. bar}" But it would work. I have resources defined in . tf” in the root of a directory you want to I have created dozens of resources using terraform azurerm, but I want a particular resource that needs to be deleted and created every time I do terraform apply. There is no way to make that decision dynamically, because that would make the result non-deterministic and -- for objects managed by Terraform -- make it unclear which To conditionally create resources in Terraform based on whether the secret already exists, you can use the count meta-argument along with conditional expressions and data sources. myserver-sig-public-ports This replaces the former workflow of terraform taint <resource_address> followed by a plan and apply. The following example shows how to optionally specify whether a resource is created (using the conditional operator), and shows how to handle returning output when a resource is not created. Sign-in Providers hashicorp aws Version 5. Usually terraform will return resource attributes that can only be determined after creation, such as DNS name, password, Id, etc. To define a resource existence conditionally, you can use this Q for reference. Share. Ask Question Asked 2 years, 6 months ago. Terraform - nested loop for I am trying to create resource aws_lb_listener with terraform interpolation for if-else condition. 11. As a workaround you can call the modules separately configuration files if you are using input variables which the user will be asked to input. For future references, you can check and create resources conditionally using the external resource data, in my case i need to createone repo for development images in one repository and i was using docker provider to build and push the image to that ecr I want to create a for loop and in it I want to create an S3 event notification, create an Sns topic that listens to that notification, create an Sqs queue and then subscribe the queue to the sns topic. We will create a Terraform configuration that creates an Amazon EC2 instance only if a certain variable is set to a specific value. @Sudhansu, you have to do a terraform apply -auto-approve not terraform plan for the code to create the resources 2022 at 7:29. I am attempting to use a dynamic block in the VMSS resource, and the idea is that this block will only be run if a variable is not set to null. You need to add AWS Provider to be able to create AWS resources. But in this case all 50 resources are created at once. Here’s a useful technique for using Terraform’s dynamic blocks to create conditional nested blocks. 4. The dynamic block for_each argument expects to receive a collection that has one element for each block you want to generate, so the best way to think about your problem is to think about producing a filtered version of var. Terraform doesn't seem to support if/else so I'm not sure what my options are. Expressions refer to or compute values within a configuration. ow do I check for the existence of a resource by name in terraform? You can't, as there is no build in functionality in TF to check for pre-existing resources. Both count and for_each can dynamically choose the number of instances of a resource. Since its a fully custom data source, you can program it to check for the existence of your resources, and use that information later in your TF config files. Skipping resource creation because of any kind of clash, not just by resource name, means that this offending resource is actually not managed by Terraform but by something else, possibly even manually. dev, stage & prod) why not create separate . Sajeer Noohukannu Sajeer Noohukannu. Create AWS Provider. vpc. 83. Terraform: If-else not working with alb_lb_listener resource. myserver-sig is replaced, add the following code to the You can use the lifecycle replace_triggered_by attribute to do this. On top of what Marcin says, which is 100% correct, if what you intend is to create the resource but optionally launch the provisioner "local_exec" (which makes no sense, Is there an if else select in Terraform? There are many resource are configured already manually in the Azure portal. The tool just isn’t built for what you want to do with it, I’m afraid. what i meant is terraform apply is also no creating the delegation, neither am i able to see the delegation in portal – Sudhansu. This is what a ternary looks like I'm trying to create a module that creates interconnect-attachments, but some parts are only defined if the attachment is using ipsec encryption and if it's not, that block must not exist in the Terraform: Create block only if variable matches certain values. Start by looking at the boolean value we are passing to create_eip in this module. How to create a terraform resource only if doesn't exists. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company In this case you’d import into a specific named instance of the resource to create the right correlation: 'vsphere_folder. For example, the statement below Conditional expressions combined with count and for_each offer the ability to control whether a resource is created, and how many instances of a resource to create. This reduces the amount of code you need to write and makes your scripts cleaner. myserver-sig is replaced, add the following code to the Hi team, Me new to the terraform environment. enable_lifecycle } # A technique for the conditional creation of resources is to have a line immediately after the one with name of the resource like: count = var. index, etc. This can be highly useful when you need to create or destroy resources based How to create a terraform resource only if doesn't exists. Terraform: Assign resource attribute to resource argument using If/Else pattern. Rather than trying to write a module that itself tries to detect whether something exists and create it if not, we recommend applying the dependency inversion approach: making the module accept the Even in this case, skipping resource creation if it exists does not make much sense because of the reasons above. To achieve this, I am planning to have depends_on. While these arguments are normally used to create multiple instances of a single resource type, they also allow you the flexibility of creating a single instance or no instances at all if an empty list or map is passed to the argument. create_resource ? 1 : 0 However, for a resource that contains a for_each loop this does not work. In this blog, I will explain how to use the If/Else conditional statement in Terraform. The issue is that the entire design of Terraform is based around the declarative specification of what resources exist, and full ownership of the lifecycle of what it creates. When using Terraform you shouldn't need to check for existing resources because you are creating a set of resources that has the same life cycle. The problem comes when assigning the NIC. index is 0: then: Assign public IP: else By design Terraform providers will typically not automatically "adopt" existing objects as now being managed by Terraform, because to do so would potentially lead to costly mistakes if you inadvertently bind a remote object to a Terraform resource and then run terraform destroy without realizing what is going to be destroyed. is_null = true. I need to omit some of the resources entirely based on variables in the Terraform’s `create_if` and `destroy_if` attributes allow you to conditionally create or destroy resources based on the values of other resources. terraform; terraform-provider-azure; Share. Commented Jan 10, 2022 at 7:39. Old. 2. create resource in Terraformにはif文がない。 しかし、環境ごとに値を変えたいなど条件分岐的な記述をしたい時がある。 Terraformでは、三項演算子と特定のプロパティを組み合わせることによって、条件分岐的な記述が可能になる。 count + 三項演算子 However, every Terraform resource has a meta-parameter you can use called count. Conditional statements are handy for controlling whether a resource should be created or not. create_resource ? 1 : 0 and I tried this with the Azure provider on resources such as: resource "azuread_service_principal_password" "auth" { service_principal_id = azuread_service_principal. Instead using 'count' we can achieve similar results. Use locals to assign expressions to variables for reuse, conditionals to declare if/then scenarios, and the splat expression to return attributes from complex value types. It defines variables for environment, feature enabling, and resource creation. What you describe as "conditionally running Terraform resource" really means "conditionally create zero or one instances of a Resource". workspace]? Expected: When the user runs terraform apply the resources are conditionally created based on the selected workspace. Since that value is just a normal list value, you can take its length in order to concisely write down what is essentially the statement "there should be one Y for each X", or in your I’m trying to write a module to DRY up some AWS CloudFront distributions across multiple environments. b) all resources that depend on them (see a)) are created. to validate your tf script. But in this case you However, there’s still a problem here. It comes in two forms. This behavior is very useful, you can modify the cloudtrail query for any purpose. Edit this page on GitHub. My concern is the resouce name, I don’t want my team to modify the terraform script to change the resource However, there’s still a problem here. In my situation, i’m attempting to create a key if none exists, so that it can be used in ec2 resource. This would allow me to create just the resources I need to confirm the changes work, e. For this specific use case you could also use Terraform 0. These expressions are straightforward but incredibly versatile. available to those conditions. if its set to 0 then no resource will be created. They will never coexist. A "splat expression" can be used to get a list of the values of an attribute for of the instances created from a resource block with count: Optionally Creating Resources # The tools for optionally creating a resource block in Terraform are the count and for_each meta-arguments. In terraform, one way to deploy a resource multiple times is by using count. How do I tell terraform to only create the resource only if it doesn't already exist? Share Add a Comment Controversial. More If/Else statement in Terraform is much more powerful than you think. Hands-on: Try the Create Dynamic Expressions tutorial. I'm using the following set up to iterate through my locals. Is there any way to change this logic, so that-resouce that uses time sleep is created However, if you are faced with this being a requirement, one approach is to use the Terraform external data resource to run a shell script, capture the date, and use that in your Terraform as a value for your tags. In Terraform, you're required to decide explicitly what system is responsible for the management of a particular object, and conversely which systems are just consuming an existing object. The thing to remember here is that you will have So imagine the scenario, I have 2 resources, one for admin users and one for non admin users, when I create the user / admin everything is fine however when I move the user from say non admin to admin, It destroys the Non admin user, and recreates the user (so passwords also go etc. Terraform conditional argument block. 5. It must be unique within your Terraform configuration. See the terraform doc link at the end of the page. Dynamic Blocks are used to create if statements inside Terraform resources. How to conditional create resource in Terraform based on a string variable. So which subscription you set in the CLI then you use it for your Terraform. Reply reply Top 3% Rank by size . It can go from creating a resource zero times to hundreds, or thousands of times. ? : "lambda. ordered_cached_behaviors that only contains the elements you want to use to create blocks. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company The answer by deniszh is pretty close, but I thought I'd clarify it a bit and clean up the syntax. Your other option here would be to force Terraform to create dependencies between these resources in the graph by using the depends_on configuration block. This can be useful for creating resources HashiCorp Terraform has an inline If/Else conditional expression that enables you to set parameters and variables programmatically based on the condition being evaluated. 0 (released May 2022). 0 resource: This keyword is used to declare a resource block. bar, you can represent AND using simple multiplication: count = "${var. Terraform is declarative, not imperative. resource_cost: This calculates a cost value based on the `resource_type` variable. 12 would properly handle those lists that's in the other answer and has now been out for more than 9 months so it's pretty reasonable to expect that people are using 0. You can think Some resources were previously created without that optional attribute being declared. The key is to structure your Terraform code in a way that allows for the conditional creation of resources without causing errors. You can set the value to true if you need to create the resource; otherwise, if you just want to read data from an existing resource, you can set it to false. Building conditiional statements inside for_each is a powerful way to control which resources are built inside complex modules. 0 Latest Version Version 5. Introduction. If there’s a custom certificate, use it: viewer_certificate { acm_certificate_arn = "" minimum_protocol_version = "TLSv1. I used to use count to do this, but wanted to get it working with for_each as it keeps the value of the variable map. Skip to How to write an if/else statement in terraform to deploy a specific resource. 12. I’m stumped on how to make the viewer_certificate block dynamic. This happens to be done using a module, and uses an object variable's element as a flag to indicate whether the resource should be created or not. The configuration for each query is defined in separate dictionaries. How to run a null_resource in terraform at the start of the script. Reason : After applying change to that resource , it's not functioning as expected. Theme. auth. Actual: 330: count = length("${local. Yes, Terraform allows you to conditionally create a resource or use a data source based on the value of a variable. 1_2016" ssl_support_method = "sni-only" } If not, I appreciate what you are suggesting and I wish this could work. In AWS using terraform, have to create a load balancer resource only when the LB does not exist. tfvars file, enabling flexible and configurable infrastructure deployments. Since that value is just a normal list value, you can take its length in order to concisely write down what is essentially the statement "there should be one Y for each X", or in your Hello, the old subject of conditional creation of a resource, if another resource already exists. { # This declaration allows everything else in the # module to just refer to e. It’s essentially a numerical value that determines how many instances of a resource to create. A value of false means that Terraform will remove the resource from state without destroying it. How is this possible? variable "google_vpc_cidr" { description = "Google Compute Engine VPC CIDR then I can use lifecycle to force a Destroy-Then-Create scenario. tf line Terraform is (sadly) not a programming language, so it's not easy (or possible) to convert any pseudo-code to HCL. Having that particular provisioner inside null_resource would make it consistent central point of execution. My Document: In Terraform a data block like you showed here is both a mechanism to fetch data and also an assertion by the author (you) that a particular external object is expected to exist in order for this configuration to be applyable. I am using the for loop in the appropriate resource: resource "aws_s3_bucket_lifecycle_configuration" "compliant_s3_bucket_lifecycle_rule" { for_each = { for bucket, values in var. Destroy All Resources; 1. Finally, if your role is not currently managed by Terraform but you would like to put it under Terraform's ownership, you can explicitly tell Terraform to start managing that existing object by importing it to create the association between the existing object and your resource block: terraform import aws_iam_role. terraform aws-provider every time A resource created by terraform after its creation comsumes CPU/RAM on cluster where it is created, so some kind of delay is needed before the next resource on the same cluster is created. I would like to avoid using terragrunt. For example, if you’re creating an AWS EC2 instance with Terraform, the resource type would be "aws_instance". Every resource in Terraform has a “count” meta-parameters that is 1 by default, but setting it to 0 (zero) prevents the resource from being created. As Martin Atkins has mentioned in the comments , it is not possible to dynamically configure the providers in terraform for now. In terraform, conditional expression can be written in below format. Both of these syntaxes support template sequences for Adding to Julio's answer, you could target multiple resources in the following manner:. Ask Question Asked 3 years, 3 months ago. Note: I'd recommend you implement a Dependency Inversion approach as described in Conditional Creation of Objects from the official Terraform documentation:. First, create a bash script in the Terraform module: I want to avoid terraform to destroy the resources that I have created previously but instead create the new one. Terraform - don't create resource if data source does not exist. Check the article “How to use Terraform Count” for more details. Terraform - conditionally creating a resource within a loop. Terraform deploy module with a condition. Error: no matching EC2 Key Pair found │ │ with data. We can use this fact with ternary operators. For example, you can use a for_each loop to build an autoscaling group module that only builds a load balancer if the user specifies it. result end_date_relative Feature Request Need the ability to check to see if an object already exists and then be able to use it else create a new object. So, Terraform will not create them at the same time. For example, the default_action block inside the aws_lb_listener resource is a literal block. Dynamic blocks can be used with any literal block inside a Terraform resource. aws_key_pair. example[1]. Use HCP Terraform for free Browse Providers Modules Policy Libraries Beta Run Tasks Beta. Maintenance mode. Are you using Terraform 0. In this tutorial, we will show you how to use multiple if statements in Terraform. non_existent are supported. Learn how to leverage Terraform's conditional logic to dynamically create resources based on variables defined in your . You can use the count parameter along with the count A conditional expression uses the value of a boolean expression to select one of two values. 12 Use-cases Example, in AWS, if a security group name xyz_sg already ex If/else. HashiTalks 2025 Learn about unique use cases, This allows you to take resources you have created by some other means and bring them under Terraform management. Follow answered Sep 6, 2019 at 5:54. Instead, you must bind existing Terraform - conditionally creating a resource within a loop. In Terraform deploying 0 resources is also fine if the condition is not met. Let’s consider a scenario where we want to conditionally create a security group resource based on the. You need to determine why Terraform thinks the resource doesn't exist, which is most likely missing state information. Q&A [deleted] • That's basically Terraform's whole job, so something else is wrong here. String literals are the most complex kind of literal expression in Terraform, and also the most commonly used. In the case of trying to apply a name to a transit gateway I think what you are describing here is the approach the documentation warns against in Conditional Creation of Objects. description = "Specifies the type of resource (e. It demonstrates basic conditional expressions using the ternary operator, handling multiple conditions similar to "elif" statements, conditional resource creation based on boolean variables, and using multiple resource blocks Make your Terraform configurations more dynamic and reusable with expressions. foo and var. Terraform v0. existence of a specific VPC. If we set count = 0, No resources will get created. When using Terraform you shouldn't need to check for existing resources. I am/want to using the terraform like this: create the AWS IAM groups and policies But when I tried to pass the new var file, I create the new resources and delete the previous one, so I want to create the new one but still want You can force the recreation (delete/create or -/+) by using the -replace=ADDRESS argument with terraform plan or terraform apply: terraform apply -replace=aws_lightsail_instance_public_ports. – @Kombajnzbożowy The issue is this terraform is triggered by different scripts in different scenarios. Follow the Customize Terraform Configuration with Variables tutorial to learn how to create Terraform variables and how to validate the values of individual variables. Normally this would be used to tell Terraform that resource foo needs to be created before resource bar but resource bar has no reference to anything from resource foo. One example of such a situation is where an object doesn't become usable until an access policy is applied to it in a separate step, such as with A dynamic block can only generate arguments that belong to the resource type, data source, provider or provisioner being configured. Once you’ve done that, Terraform will see that these items already exist and that Terraform manages them and so subsequent changes to the configuration will be applied to them by Terraform. Ask Question Asked 1 year, 9 months ago For just this one resource, these lists of URIs aren't used at all and so you could potentially simplify this to just be a set of bucket name strings and throw away the URIs; I kept it as a map both because I don't know what else you might be doing with this data structure elsewhere in your module and also because it allowed me to show a few different things about for expressions Feature Request Need the ability to check to see if an object already exists and then be able to use it else create a new object. Both of these syntaxes support template sequences for I am using the IF/ELSE pattern in Terraform to build a NIC with or without a public IP. But as the Terraform recommend: We recommend using either a Service Principal or Managed Service Identity when running Terraform non-interactively (such as when running Terraform in a CI server) - and authenticating using the Azure CLI when running Terraform locally. If I create data source with diff name, then I've to create resources also with different names and pass data values there. Outputs: . resource_name1 terraform apply -target=resource_type1. 1. I want to deploy a subnet called AzureFirewallSubnet using an if . Example: So the for_each in the block above should be a condition, and the block should only be executed if that variable is not null. 12 unless they specifically state otherwise. 5. Therefore, the count is the only approach to accomplishing Terraform Conditional Resource. You have to use join for the values, because this seems to handle the inexistence of one of the two values gracefully. For example, if I am creating a workspace for us-east-1 and provisioned resources, now role is created in AWS and . bar}" Terraform, like many programming languages or Domain-Specific Languages (DSL), has the concept of Conditional Expressions, this uses the value of a boolean expression to select two values. For count you provide just that number directly, while in for_each you provide a map or a set of strings that has a number of elements matching the Terraform | Beyond IF-ELSE. It's important to note that for Terraform it's perfectly fine to deploy zero times. use the variable/count workaround (in place of an 'if' statement) to conditional create a resource Terraform: Assign resource attribute to resource argument using If/Else pattern. Follow You can conditionally create resources by setting the count meta parameter to 0 and using the conditional ternary operator. resource_name1 Hands-on: Try the Create Dynamic Expressions tutorial. Thanks ydaetskcor for pointing out in their answer the Leveraging the If / Else Statement in Terraform. 6+, the for_each loop became available for all Terraform resources and modules. The way Terraform intends for you to handle this circumstance, is to have the configuration author specify whether to create a resource (using a resource block) or look up an existing resource (using a data block). The usual way to filter the elements of a collection For just this one resource, these lists of URIs aren't used at all and so you could potentially simplify this to just be a set of bucket name strings and throw away the URIs; I kept it as a map both because I don't know what else you might be doing with this data structure elsewhere in your module and also because it allowed me to show a few This would create a record in the private zone when var. That is only true if I have . terraform apply -var-file="dev. the issue : i’m getting “No matching key found” and the workflow terminates. If you noticed, we added the count on both resources with revert logic. Conditional logic is an indispensable component of any IaC tool, and Terraform is no exception. Hello, the old subject of conditional creation of a resource, if another resource already exists. To define conditional blocks, read this - you can pick either solution depending on how much do these resources differ. Using your ternary example, terraform plan says Plan: 10 to add, 0 to change, 10 to destroy. Terraform allows you to perform these if/else statements using a ternary operation which have become popular as short-form if/else statements in many programming languages. Customer don’t want to use the module but have asked to create using the simple resource. non_existent or local. Outputs: foo = intl-foo-bar-baz-jk-mstr $ TF_VAR_vanity_env=-dr terraform apply Apply complete! How to use if/else statement in terraform for loop. The destroy argument determines whether Terraform will attempt to destroy the object managed by the resource or not. 678 4 4 silver badges 8 8 bronze badges. , compute, storage, network). how to create variable as soon as if condition is met in terraform. internal is false. Syntax. The upshot of this is that you’ll need to ensure that anything that uses a resource that has a count, must itself, have a count (and on the same logic). Terraform boolean variable true - based on mapped values. Two meta-arguments can be used to do this in Terraform:. You can set the count of the aws_lb_listener_rule resource that will hold the redirect to a value of 1 only if the environment variable is set to prod. terraform init terraform plan -target=resource_type1. It will first create project_A and then based on the condition it will decide to create project_B. "resource_type": This is the type of resource you want to create. IF-Like Conditionals without ELSE in Terraform. environments[terraform. The logic outside terraform is like all existing resources approve adding of a new resource, but they can do it one at a time, not 3 or 50. In Terraform, you can Resources: 0 added, 0 changed, 0 destroyed. bucket_details : bucket => values if values. toao gdea ekksicng iqbou eih parzthg dflie wtucy lnzitqu rxzw