From 065d367504ae3e9b7141f7a7daa6fe1db7aeb4e7 Mon Sep 17 00:00:00 2001 From: flu0r1ne Date: Tue, 12 Sep 2023 05:19:00 -0500 Subject: Add README and script --- rbuild.py | 192 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 192 insertions(+) create mode 100644 rbuild.py (limited to 'rbuild.py') diff --git a/rbuild.py b/rbuild.py new file mode 100644 index 0000000..c39e33e --- /dev/null +++ b/rbuild.py @@ -0,0 +1,192 @@ +#!/bin/env python3 + +import argparse +import hashlib +import json +import subprocess +import tempfile +import os +import sys +from datetime import datetime +from typing import ( + List, + Dict, + Any, + Optional, + Set, + Tuple +) + +# Constants for labels +CONFIG_HASH_LABEL = 'rbuild.config_sha256' +BUILD_TIME_LABEL = 'rbuild.build_time' +COMPOSE_NAME_LABEL = 'rbuild.compose_name' + +def parse_env_var_to_int(key: str, default: Optional[int] = None) -> int: + """Parses an environment variable to an integer value.""" + try: + timeout = os.getenv(key, default=default) + return int(timeout) + except (ValueError, TypeError): + raise ValueError(f'Failed to parse "{key}", should be a numeric time in seconds') + +def die(*kargs, exit_status : int = 1, **kwargs): + """Kill the program with a custom message""" + print(*kargs, **kwargs, file=sys.stderr) + sys.exit(exit_status) + +def run_command(command: List[str]) -> str: + """Runs a command and returns the stdout.""" + + command_str = ' '.join(command) + try: + result = subprocess.run(command, stdout=subprocess.PIPE, text=True, check=True) + except subprocess.CalledProcessError as e: + die(f'Failed to run command: "{command_str}", exited={e.returncode}') + except subprocess.TimeoutExpired: + die(f'Command timed out: "{command_str}"') + return result.stdout + +def is_image_expired(image: str, config_sha256: str, build_ttl: int) -> bool: + """Checks if a docker image is expired.""" + inspect_output = run_command(['docker', 'inspect', image]) + labels = json.loads(inspect_output)[0]['Config']['Labels'] + + if labels.get('rbuild.config_sha256') != config_sha256: + return True + + build_time = datetime.fromisoformat(labels.get('rbuild.build_time')) + delta = datetime.utcnow() - build_time + + return delta.total_seconds() > build_ttl + +def remove_images(compose_name : str, operating_images : Set[str] = set()): + """ Remove images created by rbuild, provided operating_images it purges stale images""" + stale_images = [] + + image_list_output = run_command(['docker', 'image', 'list', '--format', 'json']) + for image_output in image_list_output.split('\n'): + + if not image_output: + continue + + img = json.loads(image_output) + + image_inspect_output = run_command(['docker', 'inspect', img['ID']]) + + image_details = json.loads(image_inspect_output)[0] + + labels = image_details['Config']['Labels'] + + image_name = labels.get('rbuild.compose_name') if labels else None + + if image_name != compose_name or \ + any((tag in operating_images for tag in image_details['RepoTags'])): + continue + + stale_images.append(img['ID']) + + if stale_images: + run_command(['docker', 'image', 'rm', *stale_images]) + +def read_config(filename : str) -> Tuple[str, Dict]: + """ Read the config from disk """ + + config_output = run_command(['docker', 'compose', '-f', filename, 'config', '--format', 'json']) + + config = json.loads(config_output) + + return config_output, config + +def build_main(filename: str, force_rebuild=False) -> None: + config_output, config = read_config(filename) + + config_sha256 = hashlib.sha256(config_output.encode()).hexdigest() + + name = config.get('name') + + # 2. Determine if working images are expired + ps_output = run_command(['docker', 'compose', '-f', filename, 'ps', '--all', '--format', 'json']) + containers = json.loads(ps_output) + + any_expired = False + + for container in containers: + image = container.get('Image') + if is_image_expired(image, config_sha256, BUILD_TTL): + any_expired = True + break + + if not (force_rebuild or any_expired or len(containers) == 0): + exit(0) + + # 3. Modify config + build_time = datetime.utcnow() + operating_images = set() + for service_name, service_data in config['services'].items(): + labels = service_data.setdefault('build', {}).setdefault('labels', {}) + + labels['rbuild.config_sha256'] = config_sha256 + labels['rbuild.build_time'] = build_time.isoformat() + labels['rbuild.compose_name'] = name + + new_image = f'rbuild-{name}-{service_name}:{build_time.timestamp()}' + operating_images.add(new_image) + service_data['image'] = new_image + + # 4. Save this config to a temporary JSON file + with tempfile.NamedTemporaryFile(mode='w+', suffix='.json') as temp_file: + json.dump(config, temp_file) + + temp_file.flush() + + # 5. Build and bring the dockerfile up + subprocess.run(['docker', 'compose', '-f', temp_file.name, 'build', '--no-cache', '--pull'], check=True) + subprocess.run([ + 'docker', 'compose', '-f', temp_file.name, + 'up', '--remove-orphans', '--detach', f'--wait-timeout={UP_TIMEOUT_PERIOD}' + ], check=True) + + # 6. Get rid of stale images + remove_images(name, operating_images) + +def remove_main(filename : str) -> None: + """ Remove all images """ + + _, config = read_config(filename) + compose_name = config['name'] + remove_images(compose_name) + sys.exit(0) + +if __name__ == '__main__': + BUILD_TTL = parse_env_var_to_int('BUILD_TTL', default=(24 * 60 * 60)) + UP_TIMEOUT_PERIOD = parse_env_var_to_int('UP_TIMEOUT_PERIOD', default=60) + + parser = argparse.ArgumentParser(description='Automatically rebuild a series of containers with docker compose.') + + parser.add_argument('filename', type=str, help='The docker-compose file to use.') + + parser.add_argument('--build-period', type=int, default=BUILD_TTL, help='Time images are allowed to live (in seconds.)') + parser.add_argument('--up-timeout-period', type=int, default=UP_TIMEOUT_PERIOD, help='Up timeout period in seconds.') + parser.add_argument('--force-rebuild', default=False, action='store_true', help='Force all containers to be rebuilt') + + # Add remove-images to the mutually exclusive group + parser.add_argument('--remove-images', default=False, action='store_true', help='Remove all images') + + try: + import argcomplete + argcomplete.autocomplete(parser) + except ImportError: + pass + + args = parser.parse_args() + + # Check for mutual exclusivity + if args.remove_images and args.force_rebuild: + die("Error: --remove-images cannot be used with --force-rebuild") + + if args.remove_images: + remove_main(args.filename) + + build_main(args.filename, force_rebuild=args.force_rebuild) + -- cgit v1.2.3