Terraform: Cannot parse value for variable for CIDR format

[tmtk75]

After upgrading to v0.7.0, I can see next error.

$ terraform -v
Terraform v0.7.0
...

$ terraform plan -var cidr=127.0.0.1/32
invalid value "cidr=127.0.0.1/32" for flag -var: Cannot parse value for variable cidr ("cidr=127.0.0.1/32") as valid HCL: At 1:11: expected: IDENT | STRING | ASSIGN | LBRACE got: FLOAT
Usage: terraform plan [options] [dir]

  Generates an execution plan for Terraform.

  This execution plan can be reviewed prior to running apply to get a
  sense for what Terraform will do. Optionally, the plan can be saved to
  a Terraform plan file, and apply can take this plan file to execute
  this plan exactly.

Options:

  -destroy            If set, a plan will be generated to destroy all resources
...

I could not see the error with v0.6.16.

$ /usr/local/bin/terraform -v
Terraform v0.6.16

Your version of Terraform is out of date! The latest version
is 0.7.0. You can update by downloading from www.terraform.io
...

$ /usr/local/bin/terraform plan -var cidr=127.0.0.1/32
Refreshing Terraform state prior to plan...

No changes. Infrastructure is up-to-date. This means that Terraform
could not detect any differences between your configuration and
the real physical resources that exist. As a result, Terraform
doesn't need to do anything.

Affected Resource(s)

variable, so it may be a terraform's core issue.

Terraform Configuration Files

I can reproduce with this one.

variable cidr {}

Expected Behavior

It works as 0.6.16.

Actual Behavior

I got next error.

invalid value "cidr=127.0.0.1/32" for flag -var: Cannot parse value for variable cidr ("cidr=127.0.0.1/32") as valid HCL: At 1:11: expected: IDENT | STRING | ASSIGN | LBRACE got: FLOAT

[apparentlymart]

Hi @tmtk75. Sorry for the problem here.

It looks like in Terraform 0.7 the expected syntax here was changed to support passing maps and lists as variables, in addition to strings.

I'm not 100% sure (I didn't hit this issue myself yet, since I tend to use environment variables to set Terraform variables) but I think you could get around this by making the -var argument a valid HCL declaration, like this:

terraform plan -var 'cidr="127.0.0.1/32"'

An alternative, that might be easier to read and less confusing, would be to create a separate variables file using HCL syntax and then use -var-file to reference it.

[tmtk75]

Hi @apparentlymart, thanks a lot to let me know the workaround!
It's pretty helpful to me!

Regarding my use-case, I'd like to dynamically give my current IP address into cidr_blocks of aws_security_group for a tentative instance.

I could fix my code like this and saw it worked as expected. Thank you so much!

terraform plan -var 'cidr="'`curl -s echoip.net`/32'"'

variable cidr {}

resource "aws_security_group" "test" {
...
  ingress {
      cidr_blocks = [ "${var.cidr}" ]

[kwilczynski]

@tmtk75 you gave me an idea for interesting data source :)

[mitchellh]

Closing since we got this figured out.

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