Check the below example of a Terraform configuration: You're already applying this logic in your "aws_vpn_connection", just reverse the logic for your data source: count = var.create_vpn_gateway ? If you just need access to the properties of the resource, it is better to use a Terraform data source. However due to data sources causing erroring out on failure, it is getting a bit messy: Error: Inconsistent conditional result types. What I want is to create a terraform configuration that is able to switch my lambda from javascript to java by setting a parameter to "javascript" or "java". That had me going for quite a while cos I am a dumbass. The code discussed in this post is available on Github for reference. The count meta-argument allows to specify how many instances you want to create. And, as mentioned and pre 0.12, if you made the data source conditional then anything that depends on it (even conditionally) will fail due to the eager evaluation of ternary statements in HCL1. Setting the depends_on meta-argument within data blocks defers reading of If you don't use that property, terraform will try to fetch lambda function that doesn't exist yet. Then, you have a data source denoted by the data block. (Optional) Enable feature SSH key authentication. He has worked on large-scale distributed systems across various domains and organizations. 1 What is a Terraform Conditional Data Source? instead of hard-coding them in the module or fetching them from a remote state. If you are new to Terraform, chances are that you might also get confused between data sources, locals and variables. By rejecting non-essential cookies, Reddit may still use certain cookies to ensure the proper functionality of our platform. Providers allow Terraform to interact with cloud providers, SaaS providers, and other APIs. Does contemporary usage of "neithernor" for more than two options originate in the US, Trying to determine if there is a calculation for AC in DND5E that incorporates different material items worn at the same time, Sci-fi episode where children were actually adults. Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on LinkedIn (Opens in new window), Click to email a link to a friend (Opens in new window), Click to share on Reddit (Opens in new window), Microsoft Certified: DevOps Engineer Expert, Terraform: Overview of Azure Providers and Tools, Why HashiCorp Terraform is Essential for SREs and DevOps Engineers, HashiCorp Certified: Terraform Associate DevOps / SRE Certification, Terraform Feature Flags & Environment Toggle Design Patterns, Terraform Modules: Create Reusable Infrastructure as Code, Terraform Expression: Get List Object by Attribute Value Lookup, Azure Cosmos DB Desktop Data Migration Tool v2.0. 2 Using Conditional Data Sources in Terraform, 3 Advantages of Conditional Data Sources, 4 Pitfalls of Terraform Conditional Data Source. Terraform Conditional Data Source is the key to building flexible infrastructure. You could get rid of the conditional in the output and just use a try. When setting up a block of HCL code to deploy / manage a resource, you can combine the inline If/Else conditional expression with the Resource count feature to easily be able to check a condition, then decide programmatically whether to deploy / manage the resource or not in your deployment. He has worked on large-scale distributed systems across various domains and organizations. For example, local-only data sources exist for Custom Condition Checks You can create conditions that produce custom error messages for several types of objects in a configuration. To conclude things, Terraform Data Source is a must-have ingredient if you want to streamline your infrastructure management. instead of hard-coding them in the module or fetching them from a remote state. false then the result is false_val. If there is a complex relationship between a couple of resources, you can use. Whenever you need to share the state between modules, your first choice should be terraform data sources. A Terraform conditional data source helps us read data conditionally from a resource within a Terraform configuration. Conditional Lookups Terraform fergoid October 21, 2021, 2:31pm #1 Is there any way to perform a conditional data lookup with the equivalent of something like a try / catch block. I have a need to query the existing OpsGenie team by a given name and only if the team that I am trying to create, does not exist I will create it. It allows our code to be selective when In case of any queries, please write them in the comments section below. Data sources support the filter block, to fetch specific resources. Making statements based on opinion; back them up with references or personal experience. Terraform modules that use a resource group data source can't be evaluated. then we will pass in an empty map; this will mean that the entire block will not get set! Herkese merhaba Terraform'u renmeye devam ediyoruz. EOT, "/Users/brendanthompson/.ssh/bltadmin.pub". I am trying to use conditionals for setting up cross region AWS SG CIDR access based on a simple var.I have the cross region working unconditionally with: That all works groovy. typical scenarios where they could be used. Some providers require you to configure them with endpoint URLs, cloud regions, or other settings before Terraform can use them. However, you would do well to keep a few pitfalls in mind while working with them: With this, we have successfully understood the usage of Terraform conditional data source. You can use a conditional on data sources the same as you can with resources and also from Terraform 0.13+ on modules as well: One use case for this in Terraform 0.12+ is to utilise the lazy evaluation of ternary statements like with the following: This would create a record in the private zone when var.internal is true and instead create a record in the public zone when var.internal is false. It uses a ternary operator to evaluate the value of the environment variable. Here are some common scenarios when conditionals should be used: In this section, we will go through a few ways that conditionals can be used as feature flags, there the real values obtained. Each instance will separately read from its data source with its 0 : 1 1 [deleted] 3 yr. ago [removed] apparentlymart 3 yr. ago When the condition is true, our code will iterate over a map defined in our locals, although this data resource itself has <