feat: Add terraform_docs hook settings (#245)

README.md

@@ -225,13 +225,33 @@ For [checkov](https://github.com/bridgecrewio/checkov) you need to specify each
 
 2. It is possible to pass additional arguments to shell scripts when using `terraform_docs` and `terraform_docs_without_aggregate_type_defaults`. Send pull-request with the new hook if something is missing.
 
-For these hooks, you need to specify all arguments as one:
+3. It is possible to automatically:
+    * create docfile (and PATH to it)
+    * extend exiting docs files, by appending markers to the end of file (see p.1)
+    * use different than `README.md` docfile name.
 
-```yaml
-- id: terraform_docs
-  args:
-    - tfvars hcl --output-file terraform.tfvars.model .
-```
+    ```yaml
+    - id: terraform_docs
+      args:
+        - --hook-config=--path-to-file=README.md        # Valid UNIX path. I.e. ../TFDOC.md or docs/README.md etc.
+        - --hook-config=--add-to-exiting-file=true      # Boolean. true or false
+        - --hook-config=--create-file-if-not-exist=true # Boolean. true or false
+    ```
+
+4. You can provide arguments to terraform_doc. Eg. for [configuration](https://github.com/terraform-docs/terraform-docs/blob/master/docs/user-guide/configuration.md#usage):
+
+    ```yaml
+    - id: terraform_docs
+      args:
+        - --args=--config=.terraform-docs.yml
+
+5. If you need some exotic settings, it can be be done too. I.e. this one generates HCL files:
+
+    ```yaml
+    - id: terraform_docs
+    args:
+        - tfvars hcl --output-file terraform.tfvars.model .
+    ```
 
 ### terraform_docs_replace
 

terraform_docs.sh

@@ -6,7 +6,7 @@ main() {
   parse_cmdline_ "$@"
   # Support for setting relative PATH to .terraform-docs.yml config.
   ARGS=${ARGS/--config=/--config=$(pwd)\/}
-  terraform_docs_ "${ARGS[*]}" "${FILES[@]}"
+  terraform_docs_ "${HOOK_CONFIG[*]}" "${ARGS[*]}" "${FILES[@]}"
 }
 
 initialize_() {
@@ -29,7 +29,7 @@ initialize_() {
 
 parse_cmdline_() {
   declare argv
-  argv=$(getopt -o a: --long args: -- "$@") || return
+  argv=$(getopt -o a: --long args:,hook-config: -- "$@") || return
   eval "set -- $argv"
 
   for argv; do
@@ -39,6 +39,11 @@ parse_cmdline_() {
         ARGS+=("$1")
         shift
         ;;
+      --hook-config)
+        shift
+        HOOK_CONFIG+=("$1")
+        shift
+        ;;
       --)
         shift
         FILES=("$@")
@@ -49,8 +54,9 @@ parse_cmdline_() {
 }
 
 terraform_docs_() {
-  local -r args="$1"
-  shift
+  local -r hook_config="$1"
+  local -r args="$2"
+  shift 2
   local -a -r files=("$@")
 
   local hack_terraform_docs
@@ -66,7 +72,7 @@ terraform_docs_() {
 
   if [[ -z "$is_old_terraform_docs" ]]; then # Using terraform-docs 0.8+ (preferred)
 
-    terraform_docs "0" "$args" "${files[@]}"
+    terraform_docs "0" "$hook_config" "$args" "${files[@]}"
 
   elif [[ "$hack_terraform_docs" == "1" ]]; then # Using awk script because terraform-docs is older than 0.8 and terraform 0.12 is used
 
@@ -78,20 +84,21 @@ terraform_docs_() {
     local tmp_file_awk
     tmp_file_awk=$(mktemp "${TMPDIR:-/tmp}/terraform-docs-XXXXXXXXXX")
     terraform_docs_awk "$tmp_file_awk"
-    terraform_docs "$tmp_file_awk" "$args" "${files[@]}"
+    terraform_docs "$tmp_file_awk" "$hook_config" "$args" "${files[@]}"
     rm -f "$tmp_file_awk"
 
   else # Using terraform 0.11 and no awk script is needed for that
 
-    terraform_docs "0" "$args" "${files[@]}"
+    terraform_docs "0" "$hook_config" "$args" "${files[@]}"
 
   fi
 }
 
 terraform_docs() {
   local -r terraform_docs_awk_file="$1"
-  local -r args="$2"
-  shift 2
+  local -r hook_config="$2"
+  local -r args="$3"
+  shift 3
   local -a -r files=("$@")
 
   declare -a paths
@@ -107,7 +114,32 @@ terraform_docs() {
   done
 
   local -r tmp_file=$(mktemp)
-  local -r text_file="README.md"
+
+  #
+  # Get hook settings
+  #
+  local text_file="README.md"
+  local add_to_exiting=false
+  local create_if_not_exist=false
+
+  configs=($hook_config)
+  for c in "${configs[@]}"; do
+    config=(${c//=/ })
+    key=${config[0]}
+    value=${config[1]}
+
+    case $key in
+      --path-to-file)
+        text_file=$value
+        ;;
+      --add-to-exiting-file)
+        add_to_exiting=$value
+        ;;
+      --create-file-if-not-exist)
+        create_if_not_exist=$value
+        ;;
+    esac
+  done
 
   local path_uniq
   for path_uniq in $(echo "${paths[*]}" | tr ' ' '\n' | sort -u); do
@@ -115,9 +147,40 @@ terraform_docs() {
 
     pushd "$path_uniq" > /dev/null
 
-    if [[ ! -f "$text_file" ]]; then
-      popd > /dev/null
-      continue
+    #
+    # Create file if it not exist and `--create-if-not-exist=true` provided
+    #
+    if $create_if_not_exist && [[ ! -f "$text_file" ]]; then
+      dir_have_tf_files="$(
+        find . -maxdepth 1 -type f | sed 's|.*\.||' | sort -u | grep -oE '^tf$|^tfvars$' ||
+          exit 0
+      )"
+
+      # if no TF files - skip dir
+      [ ! "$dir_have_tf_files" ] && popd > /dev/null && continue
+
+      dir="$(dirname "$text_file")"
+
+      mkdir -p "$dir"
+      echo -e "# ${PWD##*/}\n" >> "$text_file"
+      echo "<!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->" >> "$text_file"
+      echo "<!-- END OF PRE-COMMIT-TERRAFORM DOCS HOOK -->" >> "$text_file"
+    fi
+
+    # If file still not exist - skip dir
+    [[ ! -f "$text_file" ]] && popd > /dev/null && continue
+
+    #
+    # If `--add-to-exiting-file=true` set, check is in file exist "hook markers",
+    # and if not - append "hook markers" to the end of file.
+    #
+    if $add_to_exiting; then
+      HAVE_MARKER=$(grep -o '<!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->' "$text_file" || exit 0)
+
+      if [ ! "$HAVE_MARKER" ]; then
+        echo "<!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->" >> "$text_file"
+        echo "<!-- END OF PRE-COMMIT-TERRAFORM DOCS HOOK -->" >> "$text_file"
+      fi
     fi
 
     if [[ "$terraform_docs_awk_file" == "0" ]]; then
@@ -311,5 +374,6 @@ EOF
 # global arrays
 declare -a ARGS=()
 declare -a FILES=()
+declare -a HOOK_CONFIG=()
 
 [[ ${BASH_SOURCE[0]} != "$0" ]] || main "$@"