From a7e3d90daeac7b74b7231a68078cec614c8aae3d Mon Sep 17 00:00:00 2001
From: Bjorn Olsen <bjorn@cloudandthings.io>
Date: Fri, 21 Oct 2022 09:39:42 +0200
Subject: [PATCH] feat: Add --retry-once-with-cleanup to `terraform_validate`

---
 README.md                   | 14 +++++++++--
 hooks/terraform_validate.sh | 48 +++++++++++++++++++++++++++++++++----
 2 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 82c04dad6..da51720ea 100644
--- a/README.md
+++ b/README.md
@@ -652,7 +652,17 @@ Example:
         - --tf-init-args=-lockfile=readonly
     ```
 
-3. It may happen that Terraform working directory (`.terraform`) already exists but not in the best condition (eg, not initialized modules, wrong version of Terraform, etc.). To solve this problem, you can find and delete all `.terraform` directories in your repository:
+3. It may happen that Terraform working directory (`.terraform`) already exists but not in the best condition (eg, not initialized modules, wrong version of Terraform, etc.). To solve this problem, you can delete broken `.terraform` directories in your repository:
+
+    ```yaml
+    - id: terraform_validate
+      args:
+        - --hook-config=--retry-once-with-cleanup=true     # Boolean. true or false
+    ```
+
+    If `--retry-once-with-cleanup=true`, then in each failed directory the `.terraform` directory will first be deleted before retrying once more.
+    
+    An alternative solution is to find and delete all `.terraform` directories in your repository:
 
     ```bash
     echo "
@@ -666,7 +676,7 @@ Example:
 
    `terraform_validate` hook will try to reinitialize them before running the `terraform validate` command.
 
-    **Warning:** If you use Terraform workspaces, DO NOT use this workaround ([details](https://github.com/antonbabenko/pre-commit-terraform/issues/203#issuecomment-918791847)). Wait to [`force-init`](https://github.com/antonbabenko/pre-commit-terraform/issues/224) option implementation.
+    **Warning:** If you use Terraform workspaces, DO NOT use these workarounds ([details](https://github.com/antonbabenko/pre-commit-terraform/issues/203#issuecomment-918791847)). Wait to [`force-init`](https://github.com/antonbabenko/pre-commit-terraform/issues/224) option implementation.
 
 4. `terraform_validate` in a repo with Terraform module, written using Terraform 0.15+ and which uses provider `configuration_aliases` ([Provider Aliases Within Modules](https://www.terraform.io/language/modules/develop/providers#provider-aliases-within-modules)), errors out.
 
diff --git a/hooks/terraform_validate.sh b/hooks/terraform_validate.sh
index cd23a52a8..3ba568ef8 100755
--- a/hooks/terraform_validate.sh
+++ b/hooks/terraform_validate.sh
@@ -43,17 +43,57 @@ function per_dir_hook_unique_part {
   local -a -r args=("$@")
 
   local exit_code
-  local validate_output
 
-  common::terraform_init 'terraform validate' "$dir_path" || {
+  #
+  # Get hook settings
+  #
+  local retry_once_with_cleanup=false
+
+  IFS=";" read -r -a configs <<< "${HOOK_CONFIG[*]}"
+
+  for c in "${configs[@]}"; do
+
+    IFS="=" read -r -a config <<< "$c"
+    key=${config[0]}
+    value=${config[1]}
+
+    case $key in
+      --retry-once-with-cleanup)
+        retry_once_with_cleanup=$value
+        ;;
+    esac
+  done
+
+  function do_validate {
+
+    local exit_code
+    local validate_output
+
+    common::terraform_init 'terraform validate' "$dir_path" || {
+      exit_code=$?
+      return $exit_code
+    }
+
+    # pass the arguments to hook
+    validate_output=$(terraform validate "${args[@]}" 2>&1)
     exit_code=$?
+
     return $exit_code
   }
 
-  # pass the arguments to hook
-  validate_output=$(terraform validate "${args[@]}" 2>&1)
+  do_validate
   exit_code=$?
 
+  if [ $exit_code -ne 0 ] && [ "$retry_once_with_cleanup" = true ]; then
+    if [ -d .terraform ]; then
+      # Will only be displayed if validation fails again.
+      common::colorify "yellow" "Validation failed. Re-initialising: $dir_path"
+      rm -r .terraform
+      do_validate
+      exit_code=$?
+    fi
+  fi
+
   if [ $exit_code -ne 0 ]; then
     common::colorify "red" "Validation failed: $dir_path"
     echo -e "$validate_output\n\n"