Loading a CSV file into terraform

2 min read

Sometimes if you have some externally managed data it can come handy to be able to import it into terraform as a CSV file instead of having to manually enter all the date. To do so we can use the csvdecode() function

10/08/2021

terraform: Using for_each over tuples

2 min read

Let's imagine we have the following data structure:

locals { queries = [ { query = "SELECT version()"  engine = "postgresql"  }, { query = "SELECT * FROM v$version"  engine = "oracle"  }, (...) ] } 

If we want to use just some of the items on a resource we can use for_each through the resulting array of filtering the objects using a for:

for_each = [ for item in local.queries: item if item.engine == "postgresql" ] 

22/06/2021

terraform: create an array of resources using for_each

3 min read

If we need to create multiple resources of the same kind based on a set of objects, we can use the for_each keyword for creating them.

08/06/2021

terraform: Using dynamic blocks to conditionally set a block on a resource

2 min read

In the same way we can conditionally include a resource, we can also use for_each to conditionally include a nested block using terraform's dynamic blocks

For example, if we want to add a variable that controls whether we should set this value:

resource "helm_release" "spinnaker" {  name = "spinnaker"  (...)  set {  name = "halyard.additionalScripts.data.enable_mptv2"  type = "string"  value = <<-EOF  #!/bin/sh  cat $0  echo "custom mptv2"  $HAL_COMMAND config features edit --managed-pipeline-templates-v2-ui true  EOF  } } 

28/05/2021

Terraform dynamic blocks

3 min read

When we have a resource that can have multiple nested blocks to be configured we can use dynamic blocks to configure it dynamically. A perfect example is a SecurityGroup that can have multiple ingress and egress rules to be able to allow traffic. Let's use the following aws_security_group resource definition as a starting point:

resource "aws_security_group" "demo_sg" { name = "demo_sg" description = "pet2cattle demo SG with dynamic blocks" vpc_id = aws_vpc.main.id ingress { from_port = 443 to_port = 443 protocol = "tcp" cidr_blocks = [aws_vpc.main.cidr_block] } egress { from_port = 0 to_port = 0 protocol = "-1" cidr_blocks = ["0.0.0.0/0"] } } 

27/05/2021