Terraform if variable is not null. This Terraform code showcases conditional logic techniques.

Terraform if variable is not null Given that, in order to distinguish between true, false, and not set at all you can define a variable like this: variable "x_lock" { type = bool default = null } Note that it's not really true to say that this is "the equivalent of an empty Terraform is a "desired state" system, so Terraform expects you to tell it whether this configuration should be creating a directory or referring to one that already exists. delete_retention_policy_days } Here is an I am creating aws_workspace, In this terraform I am looping over the variables provided in the main file and assigning the values using for each loop. id for_each = {for k,v in local. Terraform conditionals - if variable does not exist. If the actual behavior of a feature differs from what we explicitly documented as the feature's behavior, we will usually treat that as a bug and change the feature to match the I know you can pass null to parameters of a resource so it is omitted, but what happens if you have a resource and parameter such as so resource "oci_core_network_security_group_security_rule" "nsg" { network_security_group_id = oci_core_network_security_group. encryption == "IPSEC" ? [var. tfvars. and then use conditional logic to declare an inline S3 bucket only if that input variable is null. Follow answered Jan Explanation: variables. If it is set to anything else, then count = 1, and the resource will be deployed 1 time. appId != null ] } It does not produce any errors, so null is returned. its better to use coalesce instead of try: administrator_login = coalesce(var. administrator_username, "testuser") : null How to tell the terraform not to destroy the existing resource conditinally. Within loops you can reference the name of the resource and in case there is no such resource available it won't create them, which seems to be what you tried to indicate when mentioning null. Among its many features, Hi @slalomdavidsinclair,. Variables and Outputs. create_bucket is true, and 0 (create no instances) if it's false. 12 introduces nullable arguments which would allow you to set these conditionally with something like the following Photo by Himesh Kumar Behera on Unsplash. Maybe a sample code of what I If nullable is false and the variable has a default value, then Terraform uses the default when a module input argument is null. overwrite_old_value). arn won’t be known until the apply step, because the provider marked it as “unknown” in the plan. id != null something like this: NSG, DNS Zone is created when deploying AKS terraform. delegation_name != "null", which will return true unless the delegation name is the string "null". From that requirement it follows that in order to create zero instances you’d need to provide a map with zero elements. Here is my . The decoded result may have attributes that are not The result of an expression is a value. cache_nodes. The [*] operator here is asking Terraform to translate the possibly-null string variable var. Actual Behavior. Use Terraform Modules for handling null values: If you are working with Terraform modules, you can define default values within the module itself, Hi @crmartis,. If this logic statement is true, then [1] will be passed back and the block will be created. What I cannot accomplish is passing the value of the variable which was chosen to be implemneted in the resource. secrets key_vault_id = var. All values have a type, which dictates where that value can be used and what transformations can be applied to it. key value = each. As a result, using try here is not appropriate. You could look at doing a local. "coalesce" returns # the first argument that's not null, so it'll # ignore var. Terraform 0. If myvar is 0, false or any other falsy value the test will fail (if you only intend to check for not null). terraform init not_null_check_ipa = "has null elements" not_null_check_oke_build = "has no null elements" not_null_check_size = "has null elements" If you have too many lists to check, this would get repetitive & you gotta loop these with another for a loop. But even though I have set the cloud drivers variable to 1, the terraform The strcontains function checks whether a given string can be found within another string. Each assertion requires a As written above, Terraform will require that all values in feature_flags have all of the attributes defined, although the caller can set them to null to indicate that they are unset. Terraform coalesce function takes any number of arguments and returns the first one that isn’t null or an empty string, making it a useful option when working with optional values and setting defaults. 0 – Samuel Harmer. Keeping in mind that your terraform config not shown I've used a general example of for So like if cname_records contained nothing, would for_each be able to handle the null value and thus not create any resource? – Em Ma Is there any way that I can ignore the entire block if my condition is not true, EX: image_uri = “${module. – Alok Nath. The main requirement for for_each is that you provide a map with one element per instance you want to declare. regardless of whether it was # passed in or declared inline. References Something like is present I have a variable var. Your condition here is subnet. 1 and A. : Variables in terraform Blocks: Using variables directly within I know that it is possible to make the rule variable "Optional" by setting its default value to null. It should therefore work to declare a variable as optional by setting its default to null, and then assign the value directly to the argument: # NOTE: It's conventional to name Terraform variables in lowercase Here I’ve used various type conversion functions (tostring, toset, tomap, try) to convert the input into consistent data types in a similar way to what Terraform would normally do automatically as part of applying a variable type constraint, but with additional conditional logic to substitute default values when some attributes are not set. You have a couple of questions here. Is there a neat way to do this in terraform? delete_retention_policy { days = var. I have resources defined in . I can't check if a variable is null (because they are all defined in variables. example. It comes in two forms. Note that Terraform does support traditional logical, equality, and comparison operators such as == (equal to) or != (not equal to) && (and), etc. ob : s if var. Ask Question Asked 4 years ago. k string_value = Some resources allow you to use an empty string to omit basic values and the provider will interpret this as a null value, not passing it to the API endpoint so it won't complain about it not being set properly. Steps to Reproduce. If your goal is to use different behavior when the list is empty, test the length of the list instead: If dead_letter_topic is null, then you are trying to create a google_pubsub_topic_iam_member that has a null or empty string for a topic. drives size=var. If you can share some more For example, the statement below checks if the variable var. 0 Compatibility Promises:. 12 and respective HCL2 were released, you can achieve this by just setting the default variable value to "null". ; The aws_iam_policy_document needs to pack everything into a single big string containing a JSON IAM policy document. environments[terraform. Example: So the for_each in the block above should Declare your variable like this: variable "resource_groups" { type = map(object({ location = string # (and any other attributes you need) })) default = {} nullable = false } You need to use an empty I was using the following pattern often in my code: abc = something == null ? some_default : something until I realised it can be more succinctly captured (especially when This article will explain how to use the try function to normalize a predictable value, or a soft of default, in the event that the variable or attribute isn’t set. First, let's decide that the variable being set means that it has a non-null value, and thus its default value should be null to represent the "unset" case: variable "another_definition" { type = any default = null validation { # The time constraint above is looser than we really # want, so this validation rule also enforces that # the caller This check is actually not safe. value. Terraform treats optional attributes as "unset" when you pass a null value. 0 In Terraform 1+ list() becomes tolist(). size size2=var. Here is a great link regarding loops in terraform that thoroughly explains the different types of loops and how to use them: The coalesce function takes any number of arguments and returns the first one that isn't null nor empty. How to conditionally populate an You can use a for expression with an if clause to filter elements from a collection. 10. So with all of this said, it seems like there's more to do to meet the use-case you gave here, but I'm not sure yet exactly what the right set of features for that would be, to ensure that variables The compact function removes null or empty string elements from a list. Not setting this up and making it work would be nice. Luckily we can achieve the same result by using a specific parameter called count. This is somewhat unclear, because if var. You can then decide externally whether a particular use of the module should be managing the bucket or not, either manually (just have the human operator decide) or with some Current Terraform Version Use-cases Attempted Solutions Proposal Usually other languages has feature ifdefined(var. name => x} On the case I have some values “name” under The options you have are to raise a pull request for the provider allowing you to pass an empty string, create a second module that differs only by whether it has a private network, or wait for Terraform 0. This is indeed a limitation of terraform. ; number: a numeric value. 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 Create Terraform resource if variable is not null. But for 2-3 lists, it's okay to have them this way. size3:null Therefore, I'm attempting to create or take input for size2 and size3 variable only when the values of the cloud drives are 2 and 3, respectively. Terraform won't replace null with a Hi @amanohar,. When you declare an object attribute as optional, if it is not present in the input to the variable, Terraform assigns it a null value. It defines variables for instance type and key name. Secondly, for determining which set of variables to use, I'd recommend going with a good old map in a local value. │ Error: Invalid value for module argument │ │ on main. mode, "Default") == "Default" ? coalesce(var. Hot Network Questions Dimensional analysis and integration Is there a way to confirm your Alipay works before arriving in China? How would you recode this LaTeX example, to code it in the most primitive TeX-Code? Scary thriller movie from the 90s: mother haunted by her kid(s) who died in a car The Terraform "splat" operator [*] can be used as a convenient way to translate from a value that might be either set or null into either a zero-length or one-element list, which is then more convenient to use with the collection-oriented features of the Terraform language like dynamic blocks for example:. Terraform discussion, resources, and other HashiCorp news. We encourage you also to explore how Without parentheses, higher levels will be evaluated first, so Terraform will interpret 1 + 2 * 3 as 1 + (2 * 3) and not as (1 + 2) * 3. aws_subnet being Read. You note that v. Look at this example from Terraform website: variable "override_private_ip" { type = string default = null } 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 many languages, null is considered falsey, so it is interesting this is not true in Terraform DSL. client_certificate != null && var. variables == null) ? null : jsondecode(var. Then the person using your Terraform code can optionally override that default value. This is a pragmatic tradeoff to make it easier to set simple values in common locals { test = "${ condition ? value : (elif-condition ? elif-value : else-value)}" } For a more literal "if-elif-else" approach you can embed the if short hand with other ones to produce a similar effect. count is Terraform’s oldest, simplest, and most limited iteration construct: all it does is define how many copies of the resource to Cause Problem Description Solution; Variables in Output Values: Trying to directly use an input variable within an output block's value argument. Instead of using the local variable to assign defaults, you can use the second Wondering how to make Terraform variables optional in resources, especially for attributes in object variables? If you use Terraform modules with other configuration automation tools (e. They try function in HashiCorp Terraform allows values to be read from a Data Source, input variables, or some other attribute while providing a default value if the evaluation expression errors. @dannyman Since 0. Types. key is supplied, and it changes every time terraform runs. If condition isfalse then the result is false_val. Set resource if not null. When nullable is true, null is a valid value for the variable, and the module configuration must always account for the possibility of the variable value being null. The == operator can only return true when the two operands have identical types, and the type of [] alone (without any further type conversions) is an empty tuple rather than a list of strings and so I expect that comparison is always returning false. vpc. I believe the logic in your for_each is flawed. ob if the variable isn't set, so that the for_each will either cover all of the elements or none of them:. If it is null, the default value "us-west-2a" is assigned to the availability_zone attribute of the aws_instance resource. server is set to “UbuntuServer”. The Terraform try function is able to catch errors that occur when The not_null function returns true if the given value is not a null value. vpc if it is null and return the # locally-declared VPC instead. public_zone_id value out of the decision entirely when In this case, the availability_zone variable is checked for null using a conditional statement. Handling variable not found in Terraform. tf I have. You can To make this work requires using a different strategy that avoids applying the >= operator to a null number. The number type can represent both whole numbers like . The docs also says destination_fqdns is optional. Terraform - Create Terraform resource if variable is not null. Setting var. Like this: 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 Assuming that default_tags (not shown in your question) is similar to your local. 14, there is an experimental feature for marking attributes as optional which seems like it would, once stabilized, be suitable for this use-case. Understanding Null Behavior: In Terraform, setting an argument to null is equivalent to omitting it entirely. Variables with default = null are marked as required. 8. Perhaps you meant to check if the value is not null?If so, you should remove the quotes around null so Terraform will understand it as the null keyword rather than as a string containing those characters: I need to define a resource in Terraform (v0. Terraform Test Example It is an argument. The variable loader for environment variables and -var command line options intentionally does not evaluate expressions like the I need to use only the key and value where value is NOT null I tried the following but it did not work resource "databricks_secret" "workspace" { for_each = [for key, value in local. I'm not sure why Hashicorp keeps saying it's a breaking change when it was always intended to work that way. HashiTalks 2025 Learn about unique use cases, homelab setups, and best practices at scale at our 24-hour virtual knowledge sharing event. ami_image. configs is actually accessing the correct object, but for some reason { for k, v in server_group. If the variable is set to 0 then I do not want the policy days block to be enabled. If I’m trying to conditionally create a resource based on a variable. I want to go one step deeper and make the sub-variables* optional/required. 2. tf and will return a string). In other words, you are effectively doing this: how to check a variable string with two values in terraform. I have no control over what value of var. Setting nullable to false ensures that the variable value will never be null within the module. Terraform command line arguments doesn't work with conditional expression. tfvars (shown below) vpc = "10. Additionally, you can use {% if variable is not defined %} to test the inverse. client_certificate. 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. 2. Hello, I hope everyone is ok! I use terraform 0. So I only want to set the variable if Hello, How can I put a condition on a for_each ? I need to execute the for_each only if the value is not NULL I have a ressource who get informations from a YAML file : alert_email: - name: “Name 1” query: “Query” resource “logdna_view” “my_alert_mail” { for_each = { for x in local. How is this possible? variable "google_vpc_cidr" { description = "Google Compute Engine VPC CIDR I'm hoping to be able to pass in an environment variable via the command line, and based on that, determine whether or not to fetch this data source. Terraform, conditionally execute some lines of code in template file. tf (formatted correctly) and terraform. GitHub != null } This is fixing the 50% issue, but I still have to set the tag GitHub = null. For example: IF DEFINED somevariable echo Value exists In this particular case, the negative form should be used: IF NOT DEFINED somevariable echo Value missing PS: the variable name should be used without "%" caracters. I’ve found this reference to be useful for helping me understand the null value! Create Terraform resource if variable is not null. variable "tags" { description = "A mapping of tags to assign to the bucket. 12 which will introduce the null value that will then make Terraform core ignore the parameter entirely. value } The absence of a value is represented in Terraform by the keyword null, which is valid for any type. variable "vpc" { type = string default = null } In my root directory where I actually want to define my code for project A, I have tried this in both variables. Terraform doesn’t have any sense of a Hi @camlow325!Thanks for sharing this use-case. When I set the variable instance_prefix I want to use the local variable called instance_prefix_new. Actually the module is public on GitHub and if I understand it correctly the above toggled configuration is supposed to populate this I tried when: foo|bool as mentionned but it returns false every time the variable is filled with a string that's not yes, true, Yes foo is defined doesn't work since the var is defined. locals { users_with_appId = [ for user in var. tf files in the directory. This is particularly useful when data is retrieved from an external system in JSON or YAML format and then decoded. 0. workspace_vars: { k: key, v: value} if value != null] key = each. 19 {% if variable is defined and variable %} would also check for emptiness – Vivek. 12 or later, you can assign the special value null to an argument to mark it as "unset". Functions. For instance, in the resource documentation it is written that one must specify either *_addresses or *_ip_groups. default_action_type to null or forward will not create the block. You can explicitly set a resource argument to null to indicate that no value is provided. You can add custom conditions via assert blocks, which execute at the end of the plan and apply stages and produce warnings to notify you of problems within your infrastructure. g. For example, In cases where the variable has a value not known at plan-time, consider using an object where the key is known. Firstly, you should be able to use the newer, experimental custom validation rules to assert that a value is in a specific list of values. You could also do a combination of an empty default value with a coalesce function, which is how I typically handled this back in < 0. tf? 1. The Terraform language uses the following types for its values: string: a sequence of Unicode characters representing some text, like "hello". input. foo | length > 0 doesn't work because null doesn't have a length. 1 contains the string variable, and A. It returns the first non-null value from a list of expressions. delete_retention_policy_days. In Terraform, the null value type represents the absence or omission of a value. I know with resources you can use the count property, but it doesn't seem you can use that with data sources. Also if the the private subnets are empty, then why do multiple subnets match? – Matthew Schuchard I think this will be either difficult or impossible with Terraform. terraform\modules\cognitive_account\variables. Conditional attributes in Terraform. Let’s dive into a practical example: Terraform does not have for-loops or other traditional procedural logic built into the language, so this syntax will not work. resource "aws_ec2_tag" "ami-taggging" { resource_id = data. foo ? var. The null_resource triggers reacts to changes rather than to specific values. Any idea on how to pass a null value to the virtual_network_subnet_id if the subnet variable is not present, and then if it is present obtain the subnet variable from the azurerm subnet data block? We’re using a CI/CD pipeline (when necessary) to restore a DB from a snapshot, this sets an environment variable with a snapshot ID, and then recreates the resource to be based off of that Snapshot. The be There are several issues with the count meta-argument in the question, including the use of it originally, but to answer the question's intent, you could could conditionally manage a module like:. Terraform hcl is not 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. In this case, it seems like your goal would be served by filtering all elements out of local. Using your conditional and variables: ipsec_internal_addresses = var. However if we run the pipeline to deploy/update the rest of the infrastructure, this variable will not be set and will be null, thus recreating the DB form scratch loosing all the What I want In terraform, I have a map service_map: variable "service_map" { type = map description = "Map of some services and their ports. Terraform for_each issue with data type. Terraform will not make that decision for you, because it doesn't want to implicitly take ownership of an object that is supposed to be managed by another Terraform configuration or managed outside of Terraform entirely. variable "env" { type = "string" default = null } You can't just The syntax of a conditional expression is as follows: If condition is true then the result is true_val. Passing a null value as a module input I tried set "" as value, but that of course not work. Otherwise, it returns false. Terraform If Not Null The concept of “if not null” in Terraform Terraform is an infrastructure as code (IaC) tool that enables users to define and provision infrastructure resources in a declarative manner. 5. Defines an aws_s3_bucket resource with the count meta-argument. Create Terraform resource if variable is not null. normalized_value attributes without the need to repeatedly check for and handle absent attributes that would otherwise produce errors. . So if you do something like this: variable "foo" { default = "true" } output "truthiness" { value = "${var. azurerm_private_dns_zone. Depending on whether the variable is null or not, a resource of type aws_service_discovery_service shall be created. configs : k => v if v != null } is not iterating over the How can I handle the following where the variables var can be null locals { tf_variables = (var. 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 Pre Terraform 0. " I realized that if you set the parameter to null instead of an empty string "", it will automatically remove the key from the map without having to create a for loop. I would like to dynamically create some subnets and route tables from a . For example if I have a resource like: I added in the server_group. 10. 0 complains about an empty tuple and that the collection has no elements. key) to check if the variable is defined. Defines an AWS provider. function: not_null. You can't do that at all for required attributes. I only want to use logging, when I define a non-empty logging argument in my module call:. This Terraform code showcases conditional logic techniques. resource "aws_lambda_function" "lambda" { # [EDITED] I had a use-case where type() would have been pretty helpful to use in my code for a Terraform module I was creating. workspace] == "logging" ? toset(["this"]) : [] } which will manage one declaration of the module I’m trying to write a module to DRY up some AWS CloudFront distributions across multiple environments. Modified 2 years, 5 months ago. cc_redis. 6) in the Terraform console, which makes it bit more difficult to do type inference, but not impossible!. tf line 12, in variable "client_certificate": │ 12: condition = var. But the issue that I am facing is that I am trying to pass the username only as a second variable and now I am trying that for-each loop should pick the default value if the value is not given Terraform will accept null as the given value for these attributes in the module block, since null is considered a valid value of type string. now when I apply I need to just I am creating key vault secrets with for_each resource &quot;azurerm_key_vault_secret&quot; &quot;secrets&quot; { for_each = var. applicationstack,null) From the terraform docs for lookup built-in function:. Commented May 11, 2017 at 20:09. null is equivalent to “unset”. resource "aws_backup_vault" "vaultrds" { for_each = toset([ for s in local. I can’t use overwrite = property, because if it’s set to false terraform will throw an exception attempting to overwrite the value Default as an empty list[]: when I pass the empty list the allowed_origns it fails saying that not a valid URL; Default as an null: If I pass as null, allowed_origin alone gets null and cors is passing as an empty block i. I had a quick test, but I could not get the regex to accept null as a valid option. 0/16" Internally within Terraform there is no difference between an argument set explicitly to null and one just left unset: provider logic cannot see the difference in order to make distinctions based on it. For example, by creating helper local variable users_with_appId:. In cases where input variable has nullable argument set to false and the value passed to the variable is null, the validated value is null instead of the default value. When it's not set, I want to use the local variable called instance_prefix. lab_user into a list of either zero or one elements, and then using the length of that list to decide how many aws_iam_user queries to make. The code demonstrates how to handle empty strings in Terraform when creating an AWS EC2 instance. When to use Terraform conditional create? create_if = var. possible_choice and so on). Outputs should reflect values determined after resource creation. Is there any way to have this work or must I create two config (let's call it config A. Moved block; Terraform block; Backend block. Improve this answer. 0. Also tried other values, but can't figure it out. my_optional_variable} should equal not null. That being said, the question here is basically "how to do optional inputs for required arguments". So only use this to check for not null if the variable can never have another falsy value. this_name because the naming is not uniform (it could be either of this_name. e,cors{} which also fails due to property missing error basically saying if the variable is an empty string, do not create the resources otherwise create it once. Thanks for the report. anyvar ]) @rabidscorpio. Here are my variables and locals defined inside the module: I'd like to create the following resource only if the variable var. drives==2 ? var. vnet_type == &quot; Hello everyone, quick update on this issue. If there’s a custom certificate, use it: viewer_certificate { acm_certificate_arn = "" minimum_protocol_version = "TLSv1. 5. Commented Feb 22, 2017 at 15:37. 1_2016" ssl_support_method = "sni-only" } If not, variable "my_optional_variable" { default = "null" } And override. There are lots of ways to conditionally create a map with zero elements, but one concise way I like is to use a for The key here is that Terraform does know the value for var. A common use of conditional expressions is to define defaults to replaceinvalid values: If var. You have to declare in your module that you're using the experiment: terraform { # Optional attributes and the defaults function are # both experimental, so we must opt in to the experiment. Hot Network Questions Is it acceptable programming practice to reference a part of a slot (#[[1]], #[[2]], and #[[3]], for example)? If not, what alternative should I use? Sign of the sum of alternating triple binomial coefficient Faux Random Maze Generator When defining the arguments in a resource block that are declared by the provider itself, setting an argument to null is exactly the same as not setting it at all. 7 (the current latest minor release) because Terraform is now able to internally track whether an unknown value could possibly be null, and it knows that a multi-line template expression (like you have here) can never produce null as a result, even if Terraform doesn't know exactly what characters will be Hi, I am trying to create a module for deploying workloads to AWS Fargate. – pbaranay. ; main. tf that contains: variable "my_optional_variable" { default = "not null" } Then ${var. To make this work requires using a different strategy that avoids applying the >= operator to a null number. The different operators can be gathered into a few different groups with similar behavior, as described below. Terraform: how to declare a variable as required (or optional) in variables. Modified 1 year, 5 months ago. tf files that are generic to several applications. drives==3 ? var. 64. Rather then appended together like other . I want to check a string in a variable with two string values something like the below code. simplevm_bastion_nsg. variables)["variables"] } resource " Skip to main content Terraform for_each not recognizing all values in variable. I need to omit some of the resources entirely based on variables in the . foo != "" doesn't work because the var is null not a empty string. tfvars file: vnet_spoke_objec I want to set instance prefixes depending on wheter I have set an variable or not. The can 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: drives=var. 1. 2 not. Following the documentation I’ve created: If the 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. Documentation Also I found this answer helpful working with locals. Examples of Terraform conditional create. tf: Defines a boolean variable create_bucket to control resource creation. tfvars file. Check if parameter is null or not and change variable to true or false It seems if the subnet variable is null, terraform is still trying to resolve the value if it is true and thus failing when resolving a null index. tfvars: Sets the create_bucket variable to true. url}:dummy” lifecycle { ignore_changes = [ image_uri ] } Let’s assume I am not going to use image_uri block but I still need to keep them on my module for reuse purposes without creating a new Lambda Function. stack_version,var. foo : "default-foo" }" } In rarer situations where you do intend for the caller to be in control of the keys but want to treat certain keys a special for some reason only if they are set then there are some different strategies to achieve that. I’m stumped on how to make the viewer_certificate block dynamic. 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 Ok so this is not possible because values of variables cannot be used inside variable declarations, Terraform: set variable default as null if another variable is x. google_vpc_cidr is set not empty. configs == null ? {} : condition because TF was not happy abut attempting to access the k/v’s of a null object. When using the module_variable_optional_attrs experiment, it seems that if you use lookup() to find an object key which does not exist it'll always return null, not the default, as you might expect it to. If it is true, then count = 0 and will be deployed zero times. aws_ami. I want the subject alternative list to vary depending on what environment we are deploying into, however terraform doesn't accept null values in a list. privateSubnets is empty (as you state and the values are the subnet IDs), then the lazy evaluation of the iterator would then result in no data. " I'm sure it's simple, but is there a way to set a Terraform resource variable ONLY if not null? I used the tertiary operator, but lambda function resource does not accept "null" or "" as an acceptable value. Modules. That has me fairly certain that server_group. : Store the variable's value in a locals block and reference the local variable in the output. tf:123,1-20: element 0: │ attribute in my Module VPC variables. Therefore, you can use the normal pattern for specifying optional arguments where the conditional returns a null type if you do not want to specify a value. The only case I'd expect to see Terraform plan a change for this is if the condition expression produces a value that can't be known until apply, and thus Terraform must │ Error: Attempt to get attribute from null value │ │ on modulek\main. variable "service_map" { type Terraform discussion, resources, and other HashiCorp news. Decode the constant/variable Using In this example, we use the for_each combined with a ternary operator to create the if-statement. With the above local value expressions, configuration elsewhere in the module can refer to local. I think part of the problem may be I'm trying to write up some terraform code which will create a function and preferably create a new execution role, however the user does have the option of attaching an existing role. The not_null function returns true if the given value is not a null value. Your example isn't using optional attributes and is testing the value with regex, for which null is not a valid option. I have the following module which creating a private bucket. For this, the module has a variable service_discovery_dns_namespace_id. This is why an empty string will work but not null (which means the parameter is unset). module "us-west-2" { for_each = local. Ask Question Asked 1 year, 5 months ago. I can't pass instance. This makes for a variable that by default is NOT required for terraform, and thus should be marked as Required: no in the output from terraform-docs. Override files are loaded last and merged into your configuration. 8) that has a list property that may or may not be empty depending on a variable, see volume_ids in the following definition: resource " I have created route_table module in terraform with internet_gateway_id as argument, but i want to create another route table for private subnet NAT_Instance, but route_table module does not have variable "igw_id" { default = null } variable "instance_id" { default = null } variable "name" {} Share. tags: k => v if v != null} key = each. size2:null size3 =var. You In your case there is a chain of events which leads to this problem indirectly: some_resource. virtual_network_type = var. Checks; Import. alert_email : x. The modul shall support optional configuration of AWS Service Discovery. 12 in a few months). 12. ecr_repository. ; terraform. The Null Coalesce function, represented as coalesce(), is a powerful feature in Terraform that helps handle situations where a value might be null or undefined. Viewed If you want to allow someone using your Terraform code the option of passing in a variable or not, you have to explicitly declare the variable, and give it a default value. tfvars file, and then link each subnet to the associated route table if specified. mode == null │ ├──────────────── │ │ var. This answer provides a solution to working with count resources in Optional variable in Terraform is not ignored when the value is null. The default value for nullable is true. lookup retrieves the value of a single element from a map, given its key. create_resource ? 1 : 0 However, for a resource that contains a for_each loop this does not work. tf line 66, in module "cognitive_account": │ 66: identity = [{ │ 67: type = "SystemAssigned" │ 68: }] │ │ The given value is not suitable for child module variable "identity" defined at . However, every Terraform resource has a meta-parameter you can use called count. availability_zone != null} 4. 60. enabled == false && var. Hi @jprouten,. Commented May 13, 2022 @AlokKelsey I missed that the variable name was GitHub instead of FWIW, I would not expect this problem to occur on Terraform v1. lookup(var. id description = "ssh" direction = There is support for this as a Terraform "experiment" (it's implemented, but could change or be removed in future versions). lab_user is null then the length will be zero and so no queries will be made. Hot Network Questions OpenCascadeShape does not appear to work for sphere object - no wire mesh formed I need to understand Artificers Help Locate Bathroom Vent Leak An infinite number of figures What you are actually looking for are loops. Terragrunt or Ansible) to build your infrastructure, you may need to write generic modules which expose all resource arguments as variables with the same or similar argument How can I loop over the terraform resource github_membership to skip this k => v if v. 2) where A. client_certificate is Check blocks can validate your infrastructure outside the usual resource lifecycle. Expressions. There are a few different ways to do that, including one with The second operand (the nested && testing the range of the number) can't succeed if the value is null, because >= isn't defined for null numbers. I would like to have private_dns_zone_group if the appropriat variable is not null. In the Azure provider, the azurerm_image data source requires resource_group_name to be set. micro`, the `aws_instance` resource will not be created. Without parentheses, higher levels will be evaluated first, so Terraform will interpret 1 + 2 * 3 as 1 + (2 * 3) and not as (1 + 2) * 3. Related. To expand my answer a bit: in both node_version and java_version arguments you are using the same lookup:. 6. if you are using Terraform 0. As per Terraform v1. variable Harnessing the Terraform Null Coalesce Function. In this example, we will use the dynamic block to create an I'm trying to create an AWS ACM cert. At the time of writing, in Terraform v0. users: user if user. 12, Terraform has some slightly interesting handling of booleans and integers using type coercion under the covers as it technically only supports strings, lists and maps. But I need to be able to prevent value update based on some condition (say, bool variable var. This is a consequence of the intentional design decision that we treat environment variable values for primitive-typed values as direct literal values, rather than as Terraform language expressions as we would for a complex data type. default is not null, but from your configuration it appears that it must be null. I'm honestly out of So that you can modify the actual content of the variable and in this way leaving only the desired content? The above example is only and just an idea for achieving the goal which is not applicable - the conditional operator cannot be used with map values (which should change in Terraform ver. For json output, variables with default = null are treated same as variables without any default value, which are marked as "default": null. variable " Terraform: set variable default as null if another variable is x. ; The count is set to 1 (create one instance) if var. respectively. enable_public_dns_zone, so we can rely on that to take the module. 15. key_vault_id name Hello @lukasmrtvy,. address] : null Here's a breakdown of how to manage null values and set defaults in Terraform: 1. instance_type != null && var. a is an empty string then the result is "default-a", but otherwiseit is the actual value of var Passing a null value as a module input argument will override any default value. As you (probably) know, Terraform doesn’t support if statements. 4 and I’m building a load balancer module in GCP and I’m having difficulty with the google_compute_url_map resource, because I need to create the following condition I need when the default_url_redirect map is configured the default_service must be disabled otherwise the default_service must receive the resource 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 First of all thanks a lot @alisdair for the thorough explanation about this, and apologies for not adding all the bits in the first place. It defines variables for environment, feature enabling, and resource creation. I populate many of the fields via a . setting the default to null errors because it's not a map of object I get the question is how to create an empty set or map since you can't run functions in the variables file I'll try running that in locals in main I then need to test for either null or false value of said object key in object composition with for loop. It’s fine to use boolean values in the triggers map – Terraform will automatically convert them to strings like "true" and "false" – but unfortunately there isn’t any way to trigger only when the value changes to true or constantly while the value is true. The key name is conditionally set using a ternary operator, setting it to null if the variable is an empty string, effectively skipping key assignment. If var. If the variable is empty, then the resource should be skipped. You can add one or more assert blocks within a check block to verify custom conditions. Using If Statements for aws_lb_listener. tf:. So here we go (also, I appreciate the feedback! The right thing would be to use a "if defined" statement, which is used to test for the existence of a variable. – Yes, you can filter out users without the appId. But, as mentioned, the type() function is only usable currently (Terraform v1. In locals the count object can not be used; and referencing aws_elasticache_cluster. If the variable is not set to `t2. Hot Network Questions Quant Probability Parking Question What type of valve has a screwdriver slot and no handle? When choosing 2 new spells for a high INT Wizard achieving 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. tag, you could do the following:. For the following examples I'll assume the following declaration: # NOTE: Terraform variable names are conventionally # written in lowercase, not Now that Terraform v0. 0 Azure Private Endpoint with Terraform - smart way to do mapping between Subresource and Private DNS Zone. pcnyhx civo wqycblf kbdsy ygc tgflv qutj egqdtkf eazly zgkhwf