fnctl 0.1.1

Self-hosted functions (Lambda-like) runtime and CLI

fnctl

A tiny, self-hosted functions (Lambda-like) runtime and CLI. Create small functions, run a local HTTP gateway to invoke them via GET, POST, etc., and manage per-function logs.

Installation

PyPI Installation

Use the package manager pip to install fnctl.

pip install fnctl

pipx (isolated CLI install)

pipx installs CLI tools into dedicated virtual environments and exposes their entry points on your PATH.

pipx upgrade fnctl

Usage

Create a function

# Check version
fnctl --version

# For more details use -h 
fnctl -h # Shows list of commands
fnctl serve -h # Show arguments for serve function

# Start the server (foreground, Ctrl+C to stop)
fnctl serve --host 127.0.0.1 --port 8080

# Or start in background (returns to shell)
fnctl serve --host 127.0.0.1 --port 8080 &

# Create a Python function
fnctl create hello --lang python

# Confirm that new function has been created
fnctl list

# Test that it can be called
curl -s http://127.0.0.1:8080/fn/hello
curl -s "http://127.0.0.1:8080/fn/hello?name=dev"

# To destroy a function
fnctl destroy hello

# Add --purge-logs to remove its logs
fnctl destroy hello --purge-logs

Start/Restart without server logs

Silence all HTTP server output while keeping per‑function logs untouched.

• Start (no logs):

# With PID file
fnctl serve --quiet --host 127.0.0.1 --port 8080 >/dev/null 2>&1 & echo $! >/tmp/fnctl.pid

# Without PID file
fnctl serve --quiet --host 127.0.0.1 --port 8080 >/dev/null 2>&1 &

• Restart (no logs):

# With PID file
([ -f /tmp/fnctl.pid ] && kill "$(cat /tmp/fnctl.pid)" || true; \
 fnctl serve --quiet --host 127.0.0.1 --port 8080 >/dev/null 2>&1 & echo $! >/tmp/fnctl.pid)

# Without PID file
(pkill -f 'fnctl serve' || true) && fnctl serve --quiet --host 127.0.0.1 --port 8080 >/dev/null 2>&1 &

• Stop:

# With PID file
kill "$(cat /tmp/fnctl.pid)" || true; rm -f /tmp/fnctl.pid

# Without PID file
pkill -f 'fnctl serve' || true

Notes:

• --quiet suppresses HTTP access logs; redirection to /dev/null hides the startup line and any stderr.
• Function logs are separate and can be toggled per function:
  • fnctl disable-logs <name> / fnctl enable-logs <name>

Start/Restart with server logs

If you want to see HTTP access logs in your terminal, do not use --quiet and do not redirect output to /dev/null.

• Start (with logs):

# Foreground (prints logs; Ctrl+C to stop)
fnctl serve --host 127.0.0.1 --port 8080

# Background (prints logs in current terminal session)
fnctl serve --host 127.0.0.1 --port 8080 & echo $! >/tmp/fnctl.pid

# Foreground, save logs to file (and print)
fnctl serve --host 127.0.0.1 --port 8080 2>&1 | tee -a ~/fnctl.http.log

# Background, append logs to file and save PID
fnctl serve --host 127.0.0.1 --port 8080 >>~/fnctl.http.log 2>&1 & echo $! >/tmp/fnctl.pid

• Restart (with logs):

# With PID file
([ -f /tmp/fnctl.pid ] && kill "$(cat /tmp/fnctl.pid)" || true; \
 fnctl serve --host 127.0.0.1 --port 8080 >>~/fnctl.http.log 2>&1 & echo $! >/tmp/fnctl.pid)

# Without PID file
(pkill -f 'fnctl serve' || true) && fnctl serve --host 127.0.0.1 --port 8080 >>~/fnctl.http.log 2>&1 &

# Follow the log
tail -f ~/fnctl.http.log

Function location

~/.fnctl/
  functions/
    hello/
      fnctl.json         # function config
      main.py            # template with handler(event, context)
  logs/
      hello.log          # logs for hello function

Edit your function

• Python handler: edit ~/.fnctl/functions/<name>/main.py (default entrypoint is main:handler).
• Config: edit ~/.fnctl/functions/<name>/fnctl.json to change entrypoint, enable/disable logging, or set command for exec functions.
• Reload: the server reloads the Python module automatically when the file changes; just save and curl again.

Logging

Enable/disable per function via config or CLI:

• fnctl enable-logs <name>
• fnctl disable-logs <name>

Inspect logs:

• fnctl logs <name> or follow with -f

Data directory (FNCTL_HOME)

• By default, fnctl stores data under ~/.fnctl.
• Override per shell or process:

export FNCTL_HOME=/path/to/custom/dir
fnctl create demo
fnctl serve --quiet --host 127.0.0.1 --port 8080 &

Contributing

Local Installation

# Clone repository to local machine
git clone https://github.com/vedantm8/fnctl.git
cd fnctl

# Necessary libraries on Debian-based environment
apt-get install -y python3 python3-venv python3-pip ca-certificates curl

# Create a virtual environment
python3 -m venv /opt/fnctl-venv
. /opt/fnctl-venv/bin/activate

# Install fnctl
python -m pip install --upgrade pip
python -m pip install -e .

Testing

• Run all tests with pytest:

pip3 install pytest
pytest -q

• Tests use a temporary FNCTL_HOME so they do not touch your real ~/.fnctl.

• The suite covers creating, listing, invoking, and destroying functions (with and without purging logs).

• Show print() output during tests (optional):

pytest -s -q            # disable capture to see prints live
# or
pytest -q --capture=tee-sys  # show prints while also capturing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT