selfprivacy-rest-api/selfprivacy_api/jobs/nix_collect_garbage.py
2024-09-05 15:57:27 +04:00

154 lines
4 KiB
Python

import re
import subprocess
from typing import Tuple, Iterable
from selfprivacy_api.utils.huey import huey
from selfprivacy_api.jobs import JobStatus, Jobs, Job
class ShellException(Exception):
"""Shell-related errors"""
COMPLETED_WITH_ERROR = "Error occurred, please report this to the support chat."
RESULT_WAS_NOT_FOUND_ERROR = (
"We are sorry, garbage collection result was not found. "
"Something went wrong, please report this to the support chat."
)
CLEAR_COMPLETED = "Garbage collection completed."
def delete_old_gens_and_return_dead_report() -> str:
subprocess.run(
[
"nix-env",
"-p",
"/nix/var/nix/profiles/system",
"--delete-generations",
"old",
],
check=False,
)
result = subprocess.check_output(["nix-store", "--gc", "--print-dead"]).decode(
"utf-8"
)
return " " if result is None else result
def run_nix_collect_garbage() -> Iterable[bytes]:
process = subprocess.Popen(
["nix-store", "--gc"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT
)
return process.stdout if process.stdout else iter([])
def parse_line(job: Job, line: str) -> Job:
"""
We parse the string for the presence of a final line,
with the final amount of space cleared.
Simply put, we're just looking for a similar string:
"1537 store paths deleted, 339.84 MiB freed".
"""
pattern = re.compile(r"[+-]?\d+\.\d+ \w+(?= freed)")
match = re.search(pattern, line)
if match is None:
raise ShellException("nix returned gibberish output")
else:
Jobs.update(
job=job,
status=JobStatus.FINISHED,
status_text=CLEAR_COMPLETED,
result=f"{match.group(0)} have been cleared",
)
return job
def process_stream(job: Job, stream: Iterable[bytes], total_dead_packages: int) -> None:
completed_packages = 0
prev_progress = 0
for line in stream:
line = line.decode("utf-8")
if "deleting '/nix/store/" in line:
completed_packages += 1
percent = int((completed_packages / total_dead_packages) * 100)
if percent - prev_progress >= 5:
Jobs.update(
job=job,
status=JobStatus.RUNNING,
progress=percent,
status_text="Cleaning...",
)
prev_progress = percent
elif "store paths deleted," in line:
parse_line(job, line)
def get_dead_packages(output) -> Tuple[int, float]:
dead = len(re.findall("/nix/store/", output))
percent = 0
if dead != 0:
percent = 100 / dead
return dead, percent
@huey.task()
def calculate_and_clear_dead_paths(job: Job):
Jobs.update(
job=job,
status=JobStatus.RUNNING,
progress=0,
status_text="Calculate the number of dead packages...",
)
dead_packages, package_equal_to_percent = get_dead_packages(
delete_old_gens_and_return_dead_report()
)
if dead_packages == 0:
Jobs.update(
job=job,
status=JobStatus.FINISHED,
status_text="Nothing to clear",
result="System is clear",
)
return True
Jobs.update(
job=job,
status=JobStatus.RUNNING,
progress=0,
status_text=f"Found {dead_packages} packages to remove!",
)
stream = run_nix_collect_garbage()
try:
process_stream(job, stream, dead_packages)
except ShellException as error:
Jobs.update(
job=job,
status=JobStatus.ERROR,
status_text=COMPLETED_WITH_ERROR,
error=RESULT_WAS_NOT_FOUND_ERROR,
)
def start_nix_collect_garbage() -> Job:
job = Jobs.add(
type_id="maintenance.collect_nix_garbage",
name="Collect garbage",
description="Cleaning up unused packages",
)
calculate_and_clear_dead_paths(job=job)
return job