Terraform: aws_instance: resource name can't contain dash "-"

[koooge]

Hi there, I encountered Error when I named ec2 instance "-foo".

Terraform Version

Terraform v0.10.7

Terraform Configuration Files

resource "aws_instance" "-foo" {
...
}

Debug Output

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Crash Output

* aws_instance.-foo: -foo: resource name can only contain letters, numbers, dashes, and underscores.

Expected Behavior

Above error message shows to allow resource name can contain dash,
but "-foo" occurred an error.
("foo" and "f-oo" is OK.)

Actual Behavior

error occured

Steps to Reproduce

Important Factoids

References

[apparentlymart]

Hi @koooge! Sorry for this confusing behavior, and thanks for reporting it.

In this case it is the error message that is incorrect, or at least _imprecise_. It would be more accurate to say that in addition to those restrictions the resource name must start with a letter. A dash is not allowed at the start of a name because names are used as identifiers elsewhere in the language and a leading dash could be ambiguous with a negation sign in some cases. This limitation also avoids other potential problematic situations such as names on the command line being misinterpreted as flags, etc.

This message has actually already been updated as part of the work for Terraform v0.12, which is now merged into master. The new message is:

A name must start with a letter and may contain only letters, digits, underscores, and dashes.

This updated message will be included in the v0.12.0 final release, and can already been seen in the v0.12.0-alpha1 preview release. Because of that, I'm going to close this out. Thanks again for reporting this!

[hashibot[bot]]

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