Start gpg-agent on macOS

start_gpg_agent

#!/usr/bin/env python

import os
import re
import subprocess
import sys 

def main():
    # If necessary, run gpg-agent
    if not is_running():
        subprocess.check_output(["/usr/local/bin/gpg-agent", "--daemon"])

    # Once it is running, parse its environment file
    env_file = find_environment_file()
    environment = parse_environment_file(env_file)

    # Set environment for later processes
    for name, value in environment.items():
        subprocess.check_call(["launchctl", "setenv", name, value])

def find_environment_file():
    config_file = os.path.join(os.path.expanduser("~"), ".gnupg", "gpg-agent.conf")
    env_file = None
    try:
        with open(config_file) as fd: 
            for line in fd.readlines():
                line = line.strip()
                match = re.match(r"([^ ]+) ([^ ]+)", line)
                if match and match.group(1) == "write-env-file":
                    env_file = match.group(2)
    except IOError as e:
        raise Exception("Could not open configuration file: {}".format(e))

    if env_file is None:
        raise Exception("No environment file defined")

    return env_file

def parse_environment_file(environment_file):
    environment = {}
    try:
        with open(environment_file) as fd: 
            for line in fd.readlines():
                line = line.strip()
                match = re.match(r"([^=]+)=(.*)", line)
                if match:
                    name, value = match.groups()
                    environment[name] = value
    except IOError as e:
        raise Exception("Could not open environment file: {}".format(e))

    return environment

def is_running():
    env_file = find_environment_file()
    environment = parse_environment_file(env_file)
    gpg_agent_info = environment.get("GPG_AGENT_INFO", "")

    running = True
    match = re.match(r"([^:]+):([^:]+):([^:]+)", gpg_agent_info)
    if match:
        pid = int(match.group(2))
        try:
            os.kill(pid, 0)
        except OSError:
            running = False
    else:
        running = False
    return running

if __name__ == "__main__":
    sys.exit(main())