Increase storage of a lxd container

By default lxd stopped to assign root (disk) device to a container. To modify storage volume of a container add a device like this:

lxc config device add surflyc root disk pool=default path=/ size=15GB

Restart the container to apply changes.

Log quireis in dnsmasq

Add the following line to dnsmasq configuration file: log-queries

Lxd on Fedora 31

Fedora 31 has started to use cgroups v2 by default. According to Common F31 bugs it doesn't play nice with Docker, lxd and others. To make fedora switch back to the old cgroups:

sudo grubby --update-kernel=ALL --args="systemd.unified_cgroup_hierarchy=0"

How to regenerate grub configuration

sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

wifi utils

List used wifi frequences

sudo iwlist wlp1s0 scan | grep Frequency | sort | uniq -c | sort -n

List available channels

iwlist channel

List wifi networks

nmcli d wifi

Fix isort in vscode for python2

Go to the vscode Python extension folder:

cd ~/.vscode/extensions/ms-python.python-2019.9.34911

Install latest version that is known to work with python 2:

pip2 install -t ./pythonFiles/lib/python --upgrade isort==4.3.17

python: Django-like testrunner

Django-like testrunner for non-django projects:

#!/usr/bin/env python

import argparse
import collections
import unittest
import sys


def main():
    parser = argparse.ArgumentParser(description='Django-like testrunner')
    parser.add_argument('specific_test', metavar='', type=str, nargs='?', help='Specifc test')
    parser.add_argument("--failfast", action="store_true")
    parser.add_argument("--verbosity", type=int, default=1)

    args = parser.parse_args()

    loader = unittest.TestLoader()
    all_tests = loader.discover('.', top_level_dir="./")
    suite = unittest.TestSuite()

    if args.specific_test:

        def walk_tests(tests):
            if isinstance(tests, collections.Iterable):
                for item in tests:
                    walk_tests(item)
                return
            if tests.id().startswith(args.specific_test):
                suite.addTest(tests)
            elif not str(tests).startswith("test"):
                sys.exit("Error in file %s" % tests)

        walk_tests(all_tests)
    else:
        suite.addTests(all_tests)

    unittest.TextTestRunner(verbosity=args.verbosity, failfast=args.failfast).run(suite)


if __name__ == "__main__":
    main()

fedora: SSL certificate viewer

GUI to view certificate:

gcr-viewer cert.pem

linux: List all IP addresses in a network

To list ip addresses of all connected to the network devices, use this command:

nmap -sn 192.168.0.0/24

linux: CPU benchmark

$ sysbench cpu run --time=5
sysbench 1.0.9 (using system LuaJIT 2.1.0-beta3)

Running the test with following options:
Number of threads: 1
Initializing random number generator from current time


Prime numbers limit: 10000

Initializing worker threads...

Threads started!

CPU speed:
    events per second:  1157.88

General statistics:
    total time:                          5.0008s
    total number of events:              5792

Latency (ms):
         min:                                  0.80
         avg:                                  0.86
         max:                                  3.74
         95th percentile:                      1.06
         sum:                               4998.26

Threads fairness:
    events (avg/stddev):           5792.0000/0.00
    execution time (avg/stddev):   4.9983/0.00

bash: How to check what hides behind an alias

To check what command is assigned to the alias use type command:

$ type gl
gl is aliased to `git log --oneline'

fedora: Install flashplayer in Firefox

I have flashplayer installed on my system from the official Adobe repository, but Firefox for some reason does not have flash plugin installed. You can check if your browser supports flash by navigating to this url

To make Firefox aware of flashplugin, try to create a symlink here:

cd http://isflashinstalled.com/ && ln -s /usr/lib64/flash-plugin/libflashplayer.so .

Monitor process with top

One liner to monitor a process with the name /wshub:

top -p "$(pgrep -f /wshub)"

Run command as a different user

Command runuser allows to run a command as a different user. You must be root to be able to run that command:

sudo runuser -l vagrant -c "GH=1 env"

Monitor cpu and memory usage of the process

Print every second cpu and memory usage of the process:

watch -n 1 "ps -eo pid,pcpu,pmem,args | kazy -i xnotitle -e kazy"