debian-server-tools

Various scripts and tools for mainly Debian servers.

Check shell scripts: http://www.shellcheck.net/

Code styling: https://google.github.io/styleguide/shell.xml

Bashism: https://wiki.ubuntu.com/DashAsBinSh checkbashisms -f bash-script.sh

Debian install with UTC as timezone

Select Expert install.

/backup

Tools related to archiving.

/image

Tools related to image optimization.

/input

Tools related to the terminal.

/mail

Tools related to email account management.

/monitoring

Tools related to server monitoring, alert and statistics emails.

/mysql

Tools related to database management.

/package

Tools related to Debian packages and general packaging.

/security

Security and SSL certificate related tools.

/tools

Various small tools.

/virtualization

Docker containers.

/webserver

Tools related to building webservers.

How to choose VPS provider?

1. Data center location
2. Price
3. Has own AS? Number of peers
4. Redundancy (power, network, storage, hypervisor)
5. Stores plain text passwords?
6. Free scheduled backup
7. Response time of nighttime technical support in case of network or hardware failure
8. Disk access time (~1 ms)
9. CPU speed (PassMark CPU Mark 2000+, sysbench < 20 ms, WordPress Speedtest 100-150 ms)
10. Memory speed (bandwidth64)
11. Network: worldwide and regional bandwidth, port speed, D/DoS mitigation
12. Spammer neighbors http://www.projecthoneypot.org/ http://www.senderbase.org/lookup/
13. Daytime technical and billing support

See https://github.com/szepeviktor/wordpress-speedtest/blob/master/README.md#results

Install your own SSH key

S="${HOME}/.ssh";mkdir --mode 0700 "$S";editor "${S}/authorized_keys2"

Parameters

no-port-forwarding,no-agent-forwarding,no-X11-forwarding,command="echo 'Please login as the user \"debian\" rather than the user \"root\".';echo;sleep 10" ssh-rsa AAAA...

Install a user's SSH key

U="$(stat . -c %U)";S="/home/$U/.ssh";mkdir --mode 0700 "$S";editor "${S}/authorized_keys2";chown -R $U:$U "$S"

Fast and safe transit of scripts (or any data) via copy&paste

Pack

cat $SCRIPT|xz -9|base64 -w $((COLUMNS-1))
# alias: cat $SCRIPT|transit

Unpack

cat $PASTED_FILE|base64 -d|xz -d > $SCRIPT
# alias: cat $PASTED_FILE>|transit-receive

Moving away git-dir

git init --separate-git-dir=/home/user/gitdir

Produces:

/home/user/work-dir/.git: gitdir: /home/user/git

/home/user/gitdir/config: worktree = /home/user/work-dir

Rescan the SCSI Bus to Add SCSI Devices

echo "- - -" > /sys/class/scsi_host/host0/scan

geoipupdate with free GeoLite

UserId 999999
LicenseKey 000000000000
ProductIds 506 533

Flush Google public DNS cache

http://google-public-dns.appspot.com/cache

Free CDN for GitHub

http://rawgit.com/ https://cdn.rawgit.com/USER/REPO/TAG/FILE

UNICODE owl domain name

﴾͡๏̯͡๏﴿.tk

Crontab format

.---------------- minute (0 - 59)
| .-------------- hour (0 - 23)
| |  .----------- day of month (1 - 31)
| |  | .--------- month (1 - 12)
| |  | | .------- day of week (0 - 6)
| |  | | |
* *  * * *  USER  COMMAND

crontab -e -u USER
.---------------- minute (0 - 59)
| .-------------- hour (0 - 23)
| |  .----------- day of month (1 - 31)
| |  | .--------- month (1 - 12)
| |  | | .------- day of week (0 - 6)
| |  | | |
* *  * * *  COMMAND

Writing a man page

http://asciidoc.org/