feat: Add --retry-once-with-cleanup to terraform_validate (#441)

hooks/_common.sh

@@ -299,13 +299,15 @@ function common::terraform_init {
     TF_INIT_ARGS+=("-no-color")
   fi
 
-  if [ ! -d .terraform ]; then
+  if [ ! -d .terraform/modules ] || [ ! -d .terraform/providers ]; then
     init_output=$(terraform init -backend=false "${TF_INIT_ARGS[@]}" 2>&1)
     exit_code=$?
 
     if [ $exit_code -ne 0 ]; then
       common::colorify "red" "'terraform init' failed, '$command_name' skipped: $dir_path"
       echo -e "$init_output\n\n"
+    else
+      common::colorify "green" "Command 'terraform init' successfully done: $dir_path"
     fi
   fi
 

hooks/terraform_validate.sh

@@ -24,6 +24,43 @@ function main {
   common::per_dir_hook "$HOOK_ID" "${#ARGS[@]}" "${ARGS[@]}" "${FILES[@]}"
 }
 
+#######################################################################
+# Run `terraform validate` and match errors. Requires `jq`
+# Arguments:
+#   validate_output (string with json) output of `terraform validate` command
+# Outputs:
+#   Returns integer:
+#    - 0 (no errors)
+#    - 1 (matched errors; retry)
+#    - 2 (no matched errors; do not retry)
+#######################################################################
+function match_validate_errors {
+  local validate_output=$1
+
+  local valid
+  local summary
+
+  valid=$(jq -rc '.valid' <<< "$validate_output")
+
+  if [ "$valid" == "true" ]; then
+    return 0
+  fi
+
+  # Parse error message for retry-able errors.
+  while IFS= read -r error_message; do
+    summary=$(jq -rc '.summary' <<< "$error_message")
+    case $summary in
+      "missing or corrupted provider plugins") return 1 ;;
+      "Module source has changed") return 1 ;;
+      "Module version requirements have changed") return 1 ;;
+      "Module not installed") return 1 ;;
+      "Could not load plugin") return 1 ;;
+    esac
+  done < <(jq -rc '.diagnostics[]' <<< "$validate_output")
+
+  return 2 # Some other error; don't retry
+}
+
 #######################################################################
 # Unique part of `common::per_dir_hook`. The function is executed in loop
 # on each provided dir path. Run wrapped tool with specified arguments
@@ -43,16 +80,68 @@ function per_dir_hook_unique_part {
   local -a -r args=("$@")
 
   local exit_code
-  local validate_output
+  #
+  # Get hook settings
+  #
+  local retry_once_with_cleanup
+
+  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)
+        if [ $retry_once_with_cleanup ]; then 
+          common::colorify "yellow" 'Invalid hook config. Make sure that you specify not more than one "--retry-once-with-cleanup" flag'
+          exit 1
+        fi
+        retry_once_with_cleanup=$value
+        ;;
+    esac
+  done
 
   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=$?
+  if [ "$retry_once_with_cleanup" != "true" ]; then
+    # terraform validate only
+    validate_output=$(terraform validate "${args[@]}" 2>&1)
+    exit_code=$?
+  else
+    # terraform validate, plus capture possible errors
+    validate_output=$(terraform validate -json "${args[@]}" 2>&1)
+    exit_code=$?
+
+    # Match specific validation errors
+    local -i validate_errors_matched
+    match_validate_errors "$validate_output"
+    validate_errors_matched=$?
+
+    # Errors matched; Retry validation
+    if [ "$validate_errors_matched" -eq 1 ]; then
+      common::colorify "yellow" "Validation failed. Removing cached providers and modules from \"$dir_path/.terraform\" directory"
+      # `.terraform` dir may comprise some extra files, like `environment`
+      # which stores info about current TF workspace, so we can't just remove
+      # `.terraform` dir completely.
+      rm -rf .terraform/{modules,providers}/
+
+      common::colorify "yellow" "Re-validating: $dir_path"
+
+      common::terraform_init 'terraform validate' "$dir_path" || {
+        exit_code=$?
+        return $exit_code
+      }
+
+      validate_output=$(terraform validate "${args[@]}" 2>&1)
+      exit_code=$?
+    fi
+  fi
 
   if [ $exit_code -ne 0 ]; then
     common::colorify "red" "Validation failed: $dir_path"