I’m running a packer build through a Gitlab CICD pipline.
Gitlab provides the environment variables during the run so no problems there.
However during the template coding phase I want to be able to run a local task (VSCode task) to validate the json I am writing without having to commit. Unfortunately all the variables which would normally be populated by Gitlab are coming up blank.
Is there a syntax to allow a default value to be substituted if needed like is possible in bash?
Packer supports setting default values for User Variables. Those values can be overridden when building an image using either the -var or -var-file options.
Packer does support using Environment Variables in your User Variables. However, the value of a user variables will default to a blank string if the referenced environment variable is not set. As a workaround, you could first generate a JSON -var-file using values from your environment, and then provide that file to Packer during the build process.
as a var-file passed to my validate task has done the trick. It overwrites the variable in the packer template while leaving all the others to be used.
