Version 1.1.7 blocks valid image label values

[ericnorris]

Overview of the Issue

Since version 1.1.7, likely due to #240, we are unable to publish images that have a label value that starts with a number:

Image: <redacted> has invalid labels: value "380ab351648ae3591f65fa9fb7521df0c432000e" for key "git-
sha" must match regex "^[a-z][a-z0-9_-]{0,62}$",

I believe this is overly restrictive - the documentation (https://cloud.google.com/compute/docs/labeling-resources) states (emphasis mine):

Keys and values can contain only lowercase letters, numeric characters, underscores, and dashes. All characters must use UTF-8 encoding, and international characters are allowed. Keys must start with a lowercase letter or international character.

Keys must start with a lowercase letter, but not values. In our case, the value is rejected for not starting with a letter, which I think is incorrect. We are unable to publish images using this plugin version due to this.

Reproduction Steps

1. Build an image with a label key of git-sha, and a label value of 380ab351648ae3591f65fa9fb7521df0c432000e

Plugin and Packer version

plugin-googlecompute_v1.1.7_x5.0_linux_amd64

Simplified Packer Buildfile

N/A

Operating system and Environment details

N/A

Log Fragments and crash.log files

N/A

[AlanHale25]

This is happening with our builds too.
has invalid labels: value "0300" for key "division" must match regex "^[a-z][a-z0-9_-]{0,62}$"

version 1.1.6 works fine

[chrisstaite]

Caused by #240 having the same regex for labels and keys which is invalid.

[lbajolet-hashicorp]

Good catch @ericnorris, that one's on me, I didn't read the specs enough before merging the PR earlier.

I'll open a PR to address this one ASAP, and publish another release, likely tomorrow, which hopefully will fix this problem.

[lbajolet-hashicorp]

The PR is now open, please feel free to review it to make sure I haven't forgotten any edge-case, and if possible, could I ask you to test it @ericnorris / @chrisstaite / @AlanHale25 ? Since we are releasing tomorrow, I would love to have a confirmation from any of you that the problem is indeed fixed so we can avoid another blunder.

Thanks in advance!

[lbajolet-hashicorp]

Thanks for the reviews/discussions on the PR, great insights there!

The PR is merged, and now we are releasing v1.1.8 of the plugin with that patch in, so within one hour, the new version should be available, fixing this issue.