Script to compile and format *.yaml.jinja files in Home Assistant config directory (Including systemd service)

ha_compile_jinja.service

[Unit]
Description=Compile Jinja templates to YAML in Home Assistant config directory
After=network.target
StartLimitIntervalSec=0

[Service]
Type=simple
Restart=always
RestartSec=3
ExecStart=/opt/ha_compile_jinja.sh

[Install]
WantedBy=multi-user.target

ha_compile_jinja.sh

#!/bin/bash
set -euo pipefail
HASS_CONFIG_DIR="/usr/share/hassio/homeassistant"

if ! type jinja > /dev/null 2>&1; then
  echo "jinja-cli must be installed: pip install jinja-cli (https://pypi.org/project/jinja-cli/)"
  sleep 1
  exit 1
fi
if ! type prettier > /dev/null 2>&1; then
  echo "Prettier must be installed: apt-get install nodejs npm && npm install -g prettier"
  sleep 1
  exit 1
fi

remove() {
  OUTPUT_FILE="$1${2/.jinja}"
  echo "$1$2 deleted, removing: $OUTPUT_FILE"
  rm -f "$OUTPUT_FILE"
}

compile() {
  echo "$1$2 changed, compiling to: $1${2/.jinja}"
  ERROR_LOG_FILE="$1$2.errors.log"
  OUTPUT_FILE="$1${2/.jinja}"
  echo "# DO NOT EDIT: Generated from: $2 ($0)" > "$OUTPUT_FILE"
  # Log any errors to an .errors.log file, delete if successful
  if jinja "$1$2" >> "$OUTPUT_FILE" 2> "$ERROR_LOG_FILE"; then
    (rm -f "$ERROR_LOG_FILE" || true)
    echo "Formatting $OUTPUT_FILE with Prettier..."
    prettier --write "$OUTPUT_FILE" --loglevel warn || true
  else
    (rm -f "$OUTPUT_FILE" || true)
    echo "Error compiling $1$2!"
    if [ -f "$ERROR_LOG_FILE" ]; then cat "$ERROR_LOG_FILE" >&2; fi
  fi
}

echo "Compiling Jinja templates to YAML: $HASS_CONFIG_DIR/**/*.yaml.jinja"
inotifywait -q -m -r -e modify,delete,create,move "$HASS_CONFIG_DIR" | while read DIRECTORY EVENT FILE; do
  if [[ "$FILE" != *.yaml.jinja ]]; then continue; fi

  case $EVENT in
    MODIFY*)
      compile "$DIRECTORY" "$FILE";;
    CREATE*)
      compile "$DIRECTORY" "$FILE";;
    MOVED_TO*)
      compile "$DIRECTORY" "$FILE";;
    DELETE*)
      remove "$DIRECTORY" "$FILE";;
    MOVED_FROM*)
      remove "$DIRECTORY" "$FILE";;
  esac
  sleep 0.5
done

sleep 1

thanks for sharing your script! i plan to accomplish the same with my dockerized home assistant. i will publish my example here later
i will write a docker container which waits for changes in .jinja files, renders the templates and restarts home assistant automatically

thanks for sharing your script! i plan to accomplish the same with my dockerized home assistant. i will publish my example here later i will write a docker container which waits for changes in .jinja files, renders the templates and restarts home assistant automatically

Did you ever dockerize it? Looking to do the same thing, or as an addon

I've wrapped this up as an addon here https://github.com/tonyroberts/hassio-jinja2config

Thanks @ndbroadbent, this was exactly what I was looking for to simplify some complex config!