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email validation in rails
mouse 208 · person cloud · link
Dev
Email
HowTo
Rails
Last update
2023-11-24
2023
11-24
« — » 
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validates :email,
  presence: true,
  uniqueness: { case_sensitive: false },
  format: { with: URI::MailTo::EMAIL_REGEXP }

Simply use /\A.+@.+\..+\z/i and put and end to the overkill.

Source: passwordless gem, railsguides, Stop Validating Email Addresses with Regex


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use github rubygems registry
mouse 1097 · person cloud · link
Dev
Gems
Git
HowTo
Ruby
Last update
2023-11-22
2023
11-22
«free rubygems repository with github
using personal access token»

Working with the RubyGems registry

  • generate a personal access token and grant it repo permissions (replace MY_GITHUB_TOKEN with its content)

  • cat ~/.gem/credentials

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    ---
:github: Bearer MY_GITHUB_TOKEN

  • cat .bundle/config

    Note: replace any - with ___.

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    ---
BUNDLE_HTTPS://RUBYGEMS__PKG__GITHUB__COM/ACAVALIN/: "acavalin:MY_GITHUB_TOKEN"

  • cat .gemrc

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    gem: --no-document
backtrace: false
bulk_threshold: 1000
sources:
- https://rubygems.org/
- https://acavalin:MY_GITHUB_TOKEN@rubygems.pkg.github.com/acavalin/
update_sources: true
verbose: true

  • build the gem, examples:

    • gem build name.gemspec
    • rake --tasks ; rake build

  • push gem to registry

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    gem push --key github --host https://rubygems.pkg.github.com/acavalin name-0.0.1.gem

  • use gem in project

    • Gemfile: gem "name "0.0.1", source: "https://rubygems.pkg.github.com/acavalin"
    • cmdline: gem install --clear-sources --source https://acavalin:MY_GITHUB_TOKEN@rubygems.pkg.github.com/acavalin deluge-rpc

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Linux show bind mounts
mouse 143 · person cloud · link
HowTo
Linux
Terminal
Last update
2023-11-21
2023
11-21
« — » 
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findmnt | fgrep \\[

Source: stackexchange 1 and 2


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UFW firewall setup
mouse 2463 · person cloud · link
Firewall
HowTo
Linux
RaspberryPi
Last update
2023-11-20
2023
11-20
« — »

If you are using it on a VPS then you have to enable iptables NAT beforehand.

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apt-get install ufw

# disable IPv6 rules
sed -r -i 's/IPV6=yes/IPV6=no/' /etc/default/ufw

# write rules in /lib/ufw/user.rules
ufw reset # reset to defaults
# set our defaults
ufw default allow outgoing
ufw default deny  incoming
ufw allow 22/tcp        comment ssh
ufw allow 80/tcp        comment http
ufw allow 443/tcp       comment https
ufw allow 1194/udp      comment openvpn
ufw allow 1100:1200/tcp # port range (proto required23)
ufw allow 53            # allow both tcp and udp (eg: DNS)
ufw allow from 1.2.3.4  # single host
ufw allow from 192.168.1.0/24 # subnet
ufw allow from 1.2.3.4 to any port 22 proto tcp

# block an IP if it has attempted to initiate 6 or more
# connections in the last 30 seconds
ufw limit 22/tcp

# show rules added before enabling firewall
ufw show added

# remove/insert rule
ufw status numbered
ufw delete <row_number>
ufw insert <row_number> <new rule>

# show rules
ufw show added
ufw show raw

# other reports
ufw show builtins
ufw show before-rules
ufw show user-rules
ufw show after-rules
ufw show logging-rules

# start/stop/status service
ufw enable
ufw disable
ufw status
ufw status verbose
ufw reload # reload cfg

# see logs
ufw logging low # off/low/medium/high/full
tail -f /var/log/ufw.log

# show blocked incoming ports messages from log/dmesg/journalctl
dmesg | grep UFW | sed -r 's/.*(IN=[^ ]+).*(PROTO=[^ ]+).*(DPT=[^ ]+) .*/\1 \2 \3/' | sort -u

Notes:

  1. The order of rules is critical in ufw/iptables as a packet will match the first rule, subsequent rules are ignored.
  2. If something is wrong with filtering/logs you can try to purge and reinstall uwf (especially after a distribution upgrade).

Source: CyberCiti, ArchLinux

See also: Lullabot


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Backup & restore disk/partitions
mouse 3688 · person cloud · link
Backup
HowTo
Linux
Tools
Last update
2023-11-17
2023
11-17
«squashfs»

1. Partition table

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# dump raw ms-dos table/mbr
dd if=/dev/sdX of=mbr.bin     bs=512 count=1
dd if=/dev/sdX of=mbr_2mb.bin bs=2MB count=1 # paranoia
# restore
dd if=mbr.bin of=/dev/sdX
  • using sfdisk (version > 2.26 for GPT support):
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# dump raw partition table
sfdisk -b -O disk /dev/sdX # disk-<device>-<offset>.bak
# restore
ls disk-*.bak | sed -r 's/(.+)-(0x.+).bak/dd if=\0 of=\/dev\/sdX seek=$((\2)) bs=1 conv=notrunc/' | bash

# dump partition table in text format
sfdisk -d /dev/sdX > sdcard.ptable
# restore
sfdisk    /dev/sdX < sdcard.ptable

2. Partition data

You can use FSarchiver or the old school way:

  • ext* efficient backup/restore:
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e2image -ra /dev/sdXY - | pv | 7za a -mx=9 -si sdXY.e2i.7z
7za x -so sdXY.e2i.7z | pv | dd of=/dev/sdXY bs=4K

or create a squashfs mountable image1:

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apt install squashfs-tools

# backup
mkdir tmpdir
mksquashfs tmpdir sdXY.squashfs -p "sdXY.img f 444 root root e2image -ra /dev/sdXY -" -comp xz

# mount and...
mkdir tmpdir mntdir
mount sdXY.squashfs tmpdir
pv tmpdir/sdXY.img | dd of=/dev/sdXY # ...restore or...
mount tmpdir/sdXY.img mntdir         # ...inspect
  • ntfs efficient backup/restore:
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ntfsclone -s -o - /dev/sdXY | pv | 7za a -mx=9 -si sdXY.nc.7z
7za x -so sdXY.nc.7z | pv | ntfsclone -r -O /dev/sdXY -
  • raw full backup/restore:
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dd if=/dev/sdXY | pv | 7za a -mx=9 -si sdXY.dd.7z
7za x -so sdXY.dd.7z | pv | dd of=/dev/sdXY bs=4K

Tips: dd seek/skip

  1. stackexchange - mount compressed disk image ↩