Add packer validate (#58)

.pre-commit-hooks.yaml

@@ -18,6 +18,14 @@
   exclude: \.+.terraform\/.*$
   require_serial: true
 
+- id: packer-validate
+  name: Packer validate
+  description: Validates all Packer configuration files
+  entry: hooks/packer-validate.sh
+  language: script
+  files: \.pkr.*$
+  require_serial: true
+
 - id: tflint
   name: tflint
   description: Linter for Terraform source code

README.md

@@ -7,6 +7,7 @@ supported hooks are:
 
 * **terraform-fmt**: Automatically run `terraform fmt` on all Terraform code (`*.tf` files).
 * **terraform-validate**: Automatically run `terraform validate` on all Terraform code (`*.tf` files).
+* **packer-validate**: Automatically run `packer validate` on all Packer code (`*.pkr.*` files).
 * **terragrunt-hclfmt**: Automatically run `terragrunt hclfmt` on all Terragrunt configurations.
 * **tflint**: Automatically run [`tflint`](https://github.com/terraform-linters/tflint) on all Terraform code (`*.tf` files).
 * **shellcheck**: Run [`shellcheck`](https://www.shellcheck.net/) to lint files that contain a bash [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)).

hooks/packer-validate.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+set -e
+
+# OSX GUI apps do not pick up environment variables the same way as Terminal apps and there are no easy solutions,
+# especially as Apple changes the GUI app behavior every release (see https://stackoverflow.com/q/135688/483528). As a
+# workaround to allow GitHub Desktop to work, add this (hopefully harmless) setting here.
+export PATH=$PATH:/usr/local/bin
+
+# Store and return last failure from validate so this can validate every directory passed before exiting
+VALIDATE_ERROR=0
+
+for dir in $(echo "$@" | xargs -n1 dirname | sort -u | uniq); do
+  echo "--> Running 'packer validate -syntax-only' in directory '$dir'"
+  pushd "$dir" >/dev/null
+  packer validate -syntax-only || VALIDATE_ERROR=$?
+  popd >/dev/null
+done
+
+exit ${VALIDATE_ERROR}