Coding

How to Protect your App with Simple Security

Let’s build a small API Endpoint with FastAPI and protect it with SimpleSecurity.

API key based security package for FastAPI, focused on simplicity of use:

Full functionality out of the box, no configuration required
API key security with local sqlite backend, working with both header and query parameters
Default 15 days deprecation for generated API keys
Key creation, revocation, renewing, and usage logs handled through administrator endpoints
No dependencies, only requiring FastAPI and the python standard library

Build new App

and show the Directory Structure

Need a Litte Ping Function ?

Test

cat <<'EOF'> ping.py
import argparse
from ping3 import ping, verbose_ping

def do_ping(host: str, timeout: int = 3, size: int = 1500, output: str = "json"):
    # output: json|txt
    # '21.54 ms'
    if size > 1500:
        size = 1500
    result = (
        str(
            round(
                ping(dest_addr=host, timeout=timeout, size=size, unit="ms"),
                2,
            )
        )
        + " ms"
    )
    if output.lower() == "json":
        return {"host": host, "timeout": timeout, "size": size, "result": result}
    if output.lower() == "txt":
        return result
    else:
        return f"output format '{output} unknown! use 'json|txt'"


def do_multiple_ping(host: str, count: int = 3, interval: float = 0):
    # ping 'www.stoege.net' ... 23ms
    # ping 'www.stoege.net' ... 24ms
    # ping 'www.stoege.net' ... 20ms
    verbose_ping(
        dest_addr=host,
        count=count,
        interval=interval,
    )


def main():
    # Create the argument parser
    parser = argparse.ArgumentParser(description="Ping a domain or IP address.")

    # Add the host argument
    parser.add_argument(
        "host",
        metavar="HOST",
        type=str,
        nargs="?",
        default="www.stoege.net",
        help="the domain or IP address to ping",
    )

    # Parse the command-line arguments
    args = parser.parse_args()

    # Call the ping function
    output = do_ping(host=args.host, output="json")

    # Print the ping output
    print(f"\n{output}\n")

    # Call the ping function. No return Value !
    do_multiple_ping(host=args.host, count=10, interval=0.1)


if __name__ == "__main__":
    main()
EOF

add module

poetry, venv, whatever you like

a custom logger for Python

let’s tune the default logger a bit so he write nice and colored messages.

Screenshot

config.py

a little config File …

cat <<'EOF'> config.py
LOGGER_MAX_FILE_LENGTH = 10
EOF

src/logger.py

the logger code in the ‘src’ Folder

mkdir src
cat <<'EOF'> src/logger.py
import logging
import datetime
import sys

from config import *

if isinstance(LOGGER_MAX_FILE_LENGTH, int):
    LOGGER_MAX_FILE_LENGTH = str(LOGGER_MAX_FILE_LENGTH)


def get_now() -> str:
    #
    # choose your format
    #
    current_time = datetime.datetime.now()

    # 2023-07-16 22:16:15.958
    formatted_time_1 = current_time.strftime("%Y-%m-%d %H:%M:%S.%f")[:-3]

    # 22:16:54.471
    formatted_time_2 = current_time.strftime("%H:%M:%S.%f")[:-3]

    # 22:17:21
    formatted_time_3 = current_time.strftime("%H:%M:%S")

    return formatted_time_2


class ExitOnCriticalHandler(logging.Handler):
    def emit(self, record):
        # Unset Color
        COLOR = RESET = "\033[0m"

        # Debug -> Black
        if record.levelno == logging.DEBUG:
            COLOR = "\033[0m"
        # Info -> Green
        elif record.levelno == logging.INFO:
            COLOR = "\033[92m"
        # Warn -> Blue
        elif record.levelno == logging.WARNING:
            COLOR = "\033[94m"
        # Error -> Orange
        elif record.levelno == logging.ERROR:
            COLOR = "\033[38;5;208m"
        # Critical -> Red
        elif record.levelno >= logging.CRITICAL:
            COLOR = "\033[91m"

        # Custom Line
        print(
            COLOR
            + "{:} {:} {:04} {:{w}} {:}".format(
                get_now(),
                record.levelname,
                record.lineno,
                record.filename,
                record.msg,
                w=LOGGER_MAX_FILE_LENGTH,
            )
            + RESET
        )

        # Exit on Critical
        if record.levelno >= logging.CRITICAL:
            logging.shutdown()
            print("\033[91m" + "GOT A CRITICAL -> EXIT HERE!" + "\033[0m")
            sys.exit()


# Init Logger
logger = logging.getLogger()
logger.setLevel(logging.INFO)

# Create and add the custom handler
exit_handler = ExitOnCriticalHandler()
logger.addHandler(exit_handler)


# Set Log Level
def set_log_level(level: str):
    # Parse/ Set LogLevel
    if level.lower() in ["d", "debug"]:
        logger.setLevel(logging.DEBUG)
    elif level.lower() in ["i", "info"]:
        logger.setLevel(logging.INFO)
    elif level.lower() in ["w", "warning"]:
        logger.setLevel(logging.WARNING)
    elif level.lower() in ["e", "error"]:
        logger.setLevel(logging.ERROR)
    elif level.lower() in ["c", "critical"]:
        logger.setLevel(logging.CRITICAL)

    # Custom level name mappings, Debug -> D
    logging.addLevelName(logging.DEBUG, "D")
    logging.addLevelName(logging.INFO, "I")
    logging.addLevelName(logging.WARNING, "W")
    logging.addLevelName(logging.ERROR, "E")
    logging.addLevelName(logging.CRITICAL, "C")


# Functions to Call
def ldebug(msg: str):
    logger.debug(msg)


def linfo(msg: str):
    logger.info(msg)


def lwarning(msg: str):
    logger.warning(msg)


def lerror(msg: str):
    logger.error(msg)


def lcritical(msg: str):
    logger.critical(msg)
EOF

main.py

the Main File with Argparse to set the Logging Level on Startup

Flask & JWT

getting your hands dirty with Flask and JWT

Source

https://dev.to/grahammorby/jwt-auth-in-flask-python-18i4

with some modifications by myself …

Environment

Test under macOS & OpenBSD, Poetry installed and working

Script

build virtual env

export app="app100"
export FLASK_APP="${app}/app"
poetry new ${app}
cd ${app}

set python 3.10

poetry env use $(which python3.10)
gsed -i "s/python = \"^3.*$/python = \"^3.10\"/" pyproject.toml
poetry lock

add packages

wget -4 -O requirements.txt https://raw.githubusercontent.com/GrahamMorbyDev/jwt-flask/master/requirements.txt
echo "marshmallow-sqlalchemy" >> requirements.txt
poetry add $(awk -F '==' '!/sha256/{print $1}' requirements.txt |tr '\n' ' ')
wget -4 -O ${app}/app.py https://raw.githubusercontent.com/GrahamMorbyDev/jwt-flask/master/app.py
poetry shell

create db