terraform string to map

There are easier ways to do this but in one case I had only a string with a comma delimited list of values to use as an input to terraform. I was pretty sure jsonencode and/or jsondecode could handle it but it did not. This is what I ended up doing.

bash script variable used for some other function but also needed in my code. I was after the allowed_cidrs list and has to be formatted like this:

sites1=192.168.1.10/32,sites2=192.168.1.11/32,sites3=192.168.1.13/32,sites4=192.168.1.14/32

in bash I packed the variable like this:

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variables="{\"region\":\"${region}\",\"tenancy_id\":\"${tenancy_id}\",\"ip_1\": \"${ip_1}\",\"ip_2\": \"${ip_2}\",\"allowed_cidrs\": \"sites1=192.168.1.10/32,sites2=192.168.1.11/32,sites3=${ip_3},sites4=${ip_4}\"}"

terraform variables

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variable "allowed_cidrs" {}
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locals {
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  pairs = split(",", var.allowed_cidrs)
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  allowed_cidrs = {
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    for pair in local.pairs :
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    split("=", pair)[0] => split("=", pair)[1]
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  }
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  transformed_list = [
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    for key, value in local.allowed_cidrs : {
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      description = key
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      cidr_block = value
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    }
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  ]
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}
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output "allowed_cidrs" {
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  #value = local.allowed_cidrs
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  #value = [for key, value in local.allowed_cidrs : "${key}: ${value}"]
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  value = local.transformed_list
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}

terraform dynamic block

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  dynamic "ingress_security_rules" {
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    for_each = local.transformed_list
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    content {
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        description = format("%s to mysql via NLB", ingress_security_rules.value.description)
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        source   = ingress_security_rules.value.cidr_block
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        protocol    = local.tcp_protocol_number
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        tcp_options {
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            max =  local.mysql_port_number_3306
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            min =  local.mysql_port_number_3306
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        }
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    }
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  }