diff options
Diffstat (limited to 'src/app.py')
| -rw-r--r-- | src/app.py | 280 |
1 files changed, 160 insertions, 120 deletions
@@ -1,35 +1,37 @@ #!/usr/bin/env python3 # likha-pdf — markdown to pdf, no latex required -# converts markdown to html, then html to pdf via weasyprint -# falls back to reportlab if weasyprint chokes — a pdf is always produced +# production-friendly flask app with weasyprint + reportlab fallback +import logging import os -import re import secrets import time +from pathlib import Path, PurePosixPath from flask import ( Flask, + Response, + current_app, request, send_from_directory, - render_template_string, abort, ) from markupsafe import escape from markdown import markdown -from pygments.formatters import HtmlFormatter from weasyprint import HTML +from werkzeug.middleware.proxy_fix import ProxyFix APP_NAME = "likha-pdf" -PORT = 5001 +DEFAULT_HOST = "0.0.0.0" +DEFAULT_PORT = 5001 -BASE_DIR = os.path.dirname(os.path.abspath(__file__)) -GENERATED_DIR = os.path.join(BASE_DIR, "generated") -UPLOADS_DIR = os.path.join(BASE_DIR, "uploads") -TEMPLATES_DIR = os.path.join(BASE_DIR, "templates") -PARTIALS_DIR = os.path.join(TEMPLATES_DIR, "partials") -STATIC_DIR = os.path.join(BASE_DIR, "static") +BASE_DIR = Path(__file__).resolve().parent +GENERATED_DIR = BASE_DIR / "generated" +UPLOADS_DIR = BASE_DIR / "uploads" +TEMPLATES_DIR = BASE_DIR / "templates" +PARTIALS_DIR = TEMPLATES_DIR / "partials" +STATIC_DIR = BASE_DIR / "static" ALLOWED_IMAGE_EXTS = {"png", "jpg", "jpeg", "gif", "webp", "svg"} @@ -93,16 +95,20 @@ MARKDOWN_EXT_CONFIG = { }, } -app = Flask( - __name__, - template_folder=TEMPLATES_DIR, - static_folder=STATIC_DIR, - static_url_path="/static", -) -app.config["MAX_CONTENT_LENGTH"] = 64 * 1024 * 1024 # 64 MB - # helpers +def env_bool(name, default=False): + raw = os.getenv(name) + if raw is None: + return default + return raw.strip().lower() in {"1", "true", "yes", "on"} + + +def ensure_runtime_dirs(): + GENERATED_DIR.mkdir(parents=True, exist_ok=True) + UPLOADS_DIR.mkdir(parents=True, exist_ok=True) + + def random_hex(length=32): return secrets.token_hex(length // 2) @@ -132,19 +138,15 @@ def is_allowed_image(filename): def is_safe_relative_path(path_part): - return ( - bool(path_part) - and ".." not in path_part - and "\\" not in path_part - and not path_part.startswith("/") - ) + if not path_part or "\\" in path_part: + return False + safe_path = PurePosixPath(path_part) + return not safe_path.is_absolute() and ".." not in safe_path.parts def read_partial(name, replacements=None): """read a partial html template and apply replacements""" - path = os.path.join(PARTIALS_DIR, name) - with open(path, "r", encoding="utf-8") as f: - content = f.read() + content = (PARTIALS_DIR / name).read_text(encoding="utf-8") if replacements: for token, value in replacements.items(): content = content.replace(token, value) @@ -312,7 +314,7 @@ def convert_with_weasyprint(full_html, output_path): try: doc = HTML( string=full_html, - base_url=BASE_DIR, + base_url=str(BASE_DIR), ) doc.write_pdf(output_path) return True, "" @@ -452,6 +454,7 @@ def generate_pdf(source_markdown, output_path, paper_size, margin, # weasyprint failed — fall back to reportlab try: + current_app.logger.warning("weasyprint failed, using reportlab fallback: %s", err) convert_with_reportlab( source_markdown, output_path, paper_size, margin, font_family, line_spacing, @@ -461,108 +464,145 @@ def generate_pdf(source_markdown, output_path, paper_size, margin, return False, f"weasyprint: {err} | reportlab: {fallback_err}" -# routes -@app.route("/") -def index(): - index_path = os.path.join(TEMPLATES_DIR, "index.html") - with open(index_path, "r", encoding="utf-8") as f: - return f.read() +def create_app(): + ensure_runtime_dirs() + app = Flask( + __name__, + template_folder=str(TEMPLATES_DIR), + static_folder=str(STATIC_DIR), + static_url_path="/static", + ) -@app.route("/convert", methods=["POST"]) -def convert(): - md = request.form.get("markdown", "").strip() - if not md: - return read_partial("error.html", { - "{{ message }}": "Markdown content is required.", - }), 400 + app.config["MAX_CONTENT_LENGTH"] = int(os.getenv("MAX_CONTENT_LENGTH", str(64 * 1024 * 1024))) - paper_size = pick_option( - request.form.get("paper_size", ""), "letterpaper", VALID_PAPER_SIZES, - ) - margin = pick_option( - request.form.get("margin", ""), "1in", VALID_MARGINS, - ) + if env_bool("TRUST_PROXY", default=True): + app.wsgi_app = ProxyFix(app.wsgi_app, x_for=1, x_proto=1, x_host=1, x_port=1) - font_family = request.form.get("main_font", "serif") - if font_family not in ("serif", "sans"): - font_family = "serif" + log_level = os.getenv("LOG_LEVEL", "INFO").upper() + app.logger.setLevel(log_level) - line_spacing = pick_option( - request.form.get("line_spacing", ""), "1", VALID_LINE_SPACINGS, - ) - show_page_numbers = request.form.get("page_numbers") == "on" + @app.after_request + def add_security_headers(resp): + resp.headers.setdefault("X-Content-Type-Options", "nosniff") + resp.headers.setdefault("X-Frame-Options", "DENY") + resp.headers.setdefault("Referrer-Policy", "no-referrer") + return resp - epoch = int(time.time()) - output_name = f"{APP_NAME}_{epoch}_{random_hex()}.pdf" - output_path = os.path.join(GENERATED_DIR, output_name) + @app.errorhandler(413) + def payload_too_large(_err): + return read_partial("upload_error.html", { + "{{ message }}": "request body too large.", + }), 413 + + @app.route("/healthz") + def healthz(): + return Response("ok\n", mimetype="text/plain") + + @app.route("/") + def index(): + return send_from_directory(str(TEMPLATES_DIR), "index.html") + + @app.route("/convert", methods=["POST"]) + def convert(): + md = request.form.get("markdown", "").strip() + if not md: + return read_partial("error.html", { + "{{ message }}": "Markdown content is required.", + }), 400 + + paper_size = pick_option( + request.form.get("paper_size", ""), "letterpaper", VALID_PAPER_SIZES, + ) + margin = pick_option( + request.form.get("margin", ""), "1in", VALID_MARGINS, + ) - ok, err = generate_pdf( - md, output_path, - paper_size, margin, font_family, line_spacing, show_page_numbers, - ) + font_family = request.form.get("main_font", "serif") + if font_family not in ("serif", "sans"): + font_family = "serif" - if not ok: - return read_partial("error.html", { - "{{ message }}": str(escape(tail_text(err))), - }), 500 + line_spacing = pick_option( + request.form.get("line_spacing", ""), "1", VALID_LINE_SPACINGS, + ) + show_page_numbers = request.form.get("page_numbers") == "on" + + output_name = f"{APP_NAME}_{int(time.time())}_{random_hex()}.pdf" + output_path = GENERATED_DIR / output_name + + ok, err = generate_pdf( + md, + str(output_path), + paper_size, + margin, + font_family, + line_spacing, + show_page_numbers, + ) - return read_partial("result.html", { - "{{ filename }}": str(escape(output_name)), - "{{ download_url }}": f"/download/{output_name}", - }) + if not ok: + app.logger.error("pdf generation failed: %s", err) + return read_partial("error.html", { + "{{ message }}": str(escape(tail_text(err))), + }), 500 + + return read_partial("result.html", { + "{{ filename }}": str(escape(output_name)), + "{{ download_url }}": f"/download/{output_name}", + }) + + @app.route("/upload-image", methods=["POST"]) + def upload_image(): + uploaded = request.files.get("image") + if not uploaded or not uploaded.filename or not uploaded.filename.strip(): + return read_partial("upload_error.html", { + "{{ message }}": "image file is required.", + }), 400 + + original = sanitize_filename(uploaded.filename) + if not original or not is_allowed_image(original): + return read_partial("upload_error.html", { + "{{ message }}": "unsupported image type.", + }), 400 + + ext = original.rsplit(".", 1)[-1].lower() + stored_name = f"img_{int(time.time())}_{random_hex()}.{ext}" + image_path = UPLOADS_DIR / stored_name + uploaded.save(str(image_path)) + + snippet = f"" + return read_partial("upload_result.html", { + "{{ filename }}": str(escape(stored_name)), + "{{ markdown_snippet }}": str(escape(snippet)), + "{{ preview_url }}": f"/uploads/{stored_name}", + }) + + @app.route("/uploads/<path:filename>") + def serve_upload(filename): + if not is_safe_relative_path(filename): + abort(400) + return send_from_directory(str(UPLOADS_DIR), filename, conditional=True) + + @app.route("/download/<path:filename>") + def download(filename): + if not is_safe_relative_path(filename): + abort(400) + return send_from_directory( + str(GENERATED_DIR), + filename, + as_attachment=True, + download_name=filename, + conditional=True, + ) + return app -@app.route("/upload-image", methods=["POST"]) -def upload_image(): - uploaded = request.files.get("image") - if not uploaded or not uploaded.filename or not uploaded.filename.strip(): - return read_partial("upload_error.html", { - "{{ message }}": "image file is required.", - }), 400 - original = sanitize_filename(uploaded.filename) - if not original or not is_allowed_image(original): - return read_partial("upload_error.html", { - "{{ message }}": "unsupported image type.", - }), 400 - - ext = original.rsplit(".", 1)[-1].lower() - epoch = int(time.time()) - stored_name = f"img_{epoch}_{random_hex()}.{ext}" - image_path = os.path.join(UPLOADS_DIR, stored_name) - uploaded.save(image_path) - - snippet = f"" - return read_partial("upload_result.html", { - "{{ filename }}": str(escape(stored_name)), - "{{ markdown_snippet }}": str(escape(snippet)), - "{{ preview_url }}": f"/uploads/{stored_name}", - }) - - -@app.route("/uploads/<path:filename>") -def serve_upload(filename): - if not is_safe_relative_path(filename): - abort(400) - return send_from_directory(UPLOADS_DIR, filename) - - -@app.route("/download/<path:filename>") -def download(filename): - if not is_safe_relative_path(filename): - abort(400) - return send_from_directory( - GENERATED_DIR, filename, - as_attachment=True, - download_name=filename, - ) +app = create_app() -# main if __name__ == "__main__": - os.makedirs(GENERATED_DIR, exist_ok=True) - os.makedirs(UPLOADS_DIR, exist_ok=True) - - print(f" {APP_NAME} listening on http://localhost:{PORT}") - app.run(host="0.0.0.0", port=PORT, debug=False) + host = os.getenv("HOST", DEFAULT_HOST) + port = int(os.getenv("PORT", str(DEFAULT_PORT))) + print(f" {APP_NAME} listening on http://{host}:{port}") + app.run(host=host, port=port, debug=False) |