zulip/scripts/zulip-puppet-apply

#!/usr/bin/env python3
import argparse
import configparser
import os
import re
import subprocess
import sys
import tempfile
from typing import List

import yaml

BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
sys.path.insert(0, BASE_DIR)

from scripts.lib.puppet_cache import setup_puppet_modules
from scripts.lib.zulip_tools import assert_running_as_root, parse_os_release

assert_running_as_root()

parser = argparse.ArgumentParser(description="Run Puppet")
parser.add_argument(
    "--force", "-f", action="store_true", help="Do not prompt with proposed changes"
)
parser.add_argument("--noop", action="store_true", help="Do not apply the changes")
parser.add_argument("--config", default="/etc/zulip/zulip.conf", help="Alternate zulip.conf path")
args, extra_args = parser.parse_known_args()

config = configparser.RawConfigParser()
config.read(args.config)

setup_puppet_modules()

distro_info = parse_os_release()
puppet_config = """
Exec { path => "/usr/sbin:/usr/bin:/sbin:/bin" }
"""

for pclass in re.split(r"\s*,\s*", config.get("machine", "puppet_classes")):
    if " " in pclass:
        print(
            f"The `machine.puppet_classes` setting in {args.config} must be comma-separated, not space-separated!"
        )
        sys.exit(1)
    puppet_config += f"include {pclass}\n"

# We use the Puppet configuration from the same Zulip checkout as this script
scripts_path = os.path.join(BASE_DIR, "scripts")
puppet_module_path = os.path.join(BASE_DIR, "puppet")
puppet_cmd = [
    "puppet",
    "apply",
    f"--modulepath={puppet_module_path}:/srv/zulip-puppet-cache/current",
    "-e",
    puppet_config,
]
if args.noop:
    puppet_cmd += ["--noop"]
puppet_cmd += extra_args

# Set the scripts path to be a factor so it can be used by Puppet code
puppet_env = os.environ.copy()
puppet_env["FACTER_zulip_conf_path"] = args.config
puppet_env["FACTER_zulip_scripts_path"] = scripts_path


def noop_would_change(puppet_cmd: List[str]) -> bool:
    # --noop does not work with --detailed-exitcodes; see
    # https://tickets.puppetlabs.com/browse/PUP-686
    try:
        lastrun_file = tempfile.NamedTemporaryFile()
        subprocess.check_call(
            # puppet_cmd may already contain --noop, but it is safe to
            # supply twice
            [*puppet_cmd, "--noop", "--lastrunfile", lastrun_file.name],
            env=puppet_env,
        )

        with open(lastrun_file.name) as lastrun:
            lastrun_data = yaml.safe_load(lastrun)
            resources = lastrun_data.get("resources", {})
            if resources.get("failed", 0) != 0:
                sys.exit(2)
            return resources.get("out_of_sync", 0) != 0
    except subprocess.CalledProcessError:
        sys.exit(2)
    finally:
        lastrun_file.close()


if not args.noop and not args.force:
    if not noop_would_change([*puppet_cmd, "--show_diff"]):
        sys.exit(0)

    do_apply = None
    while do_apply != "y":
        sys.stdout.write("Apply changes? [y/N] ")
        sys.stdout.flush()
        do_apply = sys.stdin.readline().strip().lower()
        if do_apply in ("", "n"):
            sys.exit(0)

if args.noop and args.force:
    if noop_would_change(puppet_cmd):
        sys.exit(1)
    else:
        sys.exit(0)

ret = subprocess.call([*puppet_cmd, "--detailed-exitcodes"], env=puppet_env)
# ret = 0 => no changes, no errors
# ret = 2 => changes, no errors
# ret = 4 => no changes, yes errors
# ret = 6 => changes, yes errors
if ret not in (0, 2):
    sys.exit(2)