snarkmaster’s gists

snarkmaster / locked_mount_via_propagation.cpp

Last active August 10, 2023 22:37

Linux demo: Creating irrevocably read-only bind mounts (`MNT_LOCK_READONLY`) via mount propagation into another user NS

	/*
	This shows one of two possible methods (as of Linux v6.4.9) for seting up a
	MNT_LOCK_READONLY mount, which is a mount that cannot be remounted
	read-write even by a fully privileged super-user. The same principle applies
	to locking NODEV, NOSUID, and NOEXEC [1].

	Hopefully, at some point the Linux kernel will support setting locked bits
	via `mount_setattr` [2], but as of v6.4.9, this appears to be the simplest way.

	This `attach_recursive_mnt`-based method works best if you can have a

snarkmaster / locked_mount_via_newns.cpp

Last active August 10, 2023 23:14

Linux demo: Creating irrevocably read-only bind mounts (`MNT_LOCK_READONLY`) via user namespace moves

	/*
	This shows one of two possible methods (as of Linux v6.4.9) for seting up a
	MNT_LOCK_READONLY mount, which is a mount that cannot be remounted
	read-write even by a fully privileged super-user. The same principle applies
	to locking NODEV, NOSUID, and NOEXEC [1].

	Hopefully, at some point the Linux kernel will support setting locked bits
	via `mount_setattr` -- see [2].

	This works as follows:

snarkmaster / clonecaps.c

Created October 3, 2020 03:11

	/*
	This is a unfinished program that's part of a `libcap-ng` bug report.

	The bug repro looks like this -- the target PID 3554846 is just a random
	unprivileged process:

	echo target: &&
	grep ^Cap /proc/3554846/status &&
	sudo capsh --drop=cap_chown -- -c '
	echo under capsh: &&

snarkmaster / deepfrozen.py

Created July 17, 2020 20:52

	'''

	`deepfrozen`: Recursively immutable types that support inheritance.

	- Unlike frozen `dataclass`es or `NamedTuple`s, this lets you make
	types recursively immutable.
	- Unlike `dataclass` the immutability guarantee is strong, you cannot
	bypass it via `setattr`.
	- Unlike `NamedTuple` this supports inheritance.
	- Unlike `PyRecord`, this is immutable and hashable.

snarkmaster / rpm_location_parser.py

Created September 13, 2018 18:28

Parsing RPM location href from the repo's primary XML

	class _RpmLocationParser(AbstractContextManager):
	'''
	Parses through -primary.xml.gz and extracts `href` from each `location`.
	NB: This XML parsing takes ~4 seconds, while it takes ~1.5 seconds to
	unpack -primary.sqlite.bz2 and `SELECT location_href FROM packages`.
	'''

	def __init__(self):
	self.decompressor = zlib.decompressobj(wbits=zlib.MAX_WBITS + 16)
	self.xml_parser = XMLPullParser(['start'])

snarkmaster / example_to_list_done_or_failed_bistro_jobs.py

Created August 19, 2018 06:07

	response = query_bistro(args, {
	'h': {'handler': 'histogram'},
	'j': {'handler': 'jobs'},
	})
	jobs = response['j']['data']
	histograms = response['h']['data']['histograms']

	for job_id, job in jobs.iteritems():
	print('Number of done or failed tasks for', job_id, '-', sum(
	count for enc_bits, count in histograms[job_id][

snarkmaster / make-API-more-complex.diff

Created August 6, 2018 03:35

	From afb9cfba2854c48e1995e1c4940d679469febd94 Mon Sep 17 00:00:00 2001
	From: Alexey Spiridonov <[email protected]>
	Date: Sun, 5 Aug 2018 15:36:06 -0700
	Subject: [PATCH] Switch to a more complex plugin invocation API

	---
	mypy/plugin.py \| 11 ++++++-----
	mypy/semanal.py \| 7 ++++++-
	2 files changed, 12 insertions(+), 6 deletions(-)

snarkmaster / gist:3f78cf04cfacb7abf2a8da9b95298075

Created February 13, 2018 01:38

	(mypy) lesha@ubuntu:~/github/snarkmaster/mypy$ ./runtests.py
	PARALLEL 1
	SUMMARY 127 tasks selected
	============================= test session starts ==============================
	platform linux -- Python 3.6.4, pytest-3.4.0, py-1.5.2, pluggy-0.6.0
	rootdir: /home/lesha/github/snarkmaster/mypy, inifile: pytest.ini
	plugins: xdist-1.22.0, forked-0.2, cov-2.5.1
	gw0 [5691]
	scheduling tests via LoadScheduling
	..............................s......................................... [ 1%]