Автор: Marribi

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terraform

Terraform

Dry run inside project folder:
terraform plan

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Linux

tar

Show contents of the package:
root# tar -tzf archiv.tar.gz

Extract files here:
root# tar -xzf archiv.tar.gz

Extract only some file by mask:
root# tar -xzf archiv.tar.gz "*.log"

Extract to a directory:
root# tar -xzf archiv.tar.gz -C dir



Show contents of the bzip2 package:
tar -tjf archiv.tar.bz2

Extract files here:
root# tar -xjf archiv.tar.gz

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apt-get Linux

apt-get

To make 1 machine cache apt packages for hole net install apt-cacher (or apt-cacher-ng, squid-deb-proxy, apt-proxy, approx)

You do NOT need httpd (apache) for standard configuration (port 3142).
Logs file location: /var/log/apt-cacher

root# apt-get install apt-cacher

# File /etc/default/apt-cacher
vi /etc/default/apt-cacher
AUTOSTART=1


# File /etc/apt-cacher/apt-cacher.conf
vi  /etc/apt-cacher/apt-cacher.conf
...
daemon_addr=192.168.0.1
allowed_hosts=192.168.0.0/24
...


root# service apt-cacher start

#Import already downloaded apt packages to apt-chacher
root# cd /usr/share/apt-cacher
root# ./apt-cacher-import.pl /var/cache/apt/archives

Client-side configuration.
Check if
http://apt-cacher:3142
http://apt-cacher:3142/report
are reachable. (with curl or browser)

And change apt conf file:

# File /apt/apt.conf.d/01proxy
vi /apt/apt.conf.d/01proxy
Acquire::http::Proxy "http://apt-cacher:3142/"
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Bash Linux ping

ping

Log ping to host with timestamp.

@echo off

set /p host=HOST ADDRESS: 
set logfile=Log_%host%.log

echo Target Host = %host% >%logfile%
for /f "tokens=*" %%A in ('ping %host% -n 1 ') do (echo %%A>>%logfile% && GOTO Ping)
:Ping
for /f "tokens=* skip=2" %%A in ('ping %host% -n 1 ') do (
    echo %date% %time:~0,2%:%time:~3,2%:%time:~6,2% %%A>>%logfile%
    echo %date% %time:~0,2%:%time:~3,2%:%time:~6,2% %%A
    timeout 1 >NUL 
    GOTO Ping)

Ping some host with date every minute:

screen -dmS ping_from_edge1_to_edge2_eth0 bash -c 'while true; do date +"%Y-%m-%d  %T" ; ping -c 60 IP_ADDRESS; done >> /home/user/ping_edge1_to_edge2_eth0.log'

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k8s Linux Performance tests storage

fio (IOPS test)

Original topic can be accessed by https://www.ibm.com/cloud/blog/using-fio-to-tell-whether-your-storage-is-fast-enough-for-etcd


Test IOPS in Linux system.

tar -xzf fio.tgz
yum localinstall *.rpm
cd /data0/etcd
mkdir test-data;fio —rw=write —ioengine=sync —fdatasync=1 —directory=test-data —size=22m —bs=2300 —name=mytest

fio rpmsСкачать
#!/bin/bash
now=$(date "+%Y%d%m-%H%M");
while true;
do
fio --rw=write --ioengine=sync --fdatasync=1 --directory=/data0/etcd/test-data --size=22m --bs=2300 --name=${now}_mytest >> /data0/etcd/results.log;
sleep 600;
done
Original IBM Topic text on use of FIOСкачать
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Bash Linux

Linux repositories

To install Centos 7 EPEL repository execute:
#yum install -y epel-release

or install it from rpm:
#wget https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
#yum install -y epel-release-latest-7.noarch.rpm

list repos:
yum repolist

Search package in the repository:
yum search package_name

Get information about the package:
yum info package_name

Install package:
yum install package_name

List all available packages in a specific repository called repo_name (will also disable all other repositories):
yum --disablerepo="*" --enablerepo="repo_name" list available

Find a specific package in a specific repository:
yum --disablerepo="*" --enablerepo="repo_name" list available | grep 'package_name'

List output of packages in a specific repository:
yum --disablerepo="*" --enablerepo="repo_name" list available | less

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Bash Linux

find

Find files in current catalog with text «sometext»:
find -type f -exec grep -q sometext {} \; -print

Find all files in all subdirectories and execute script/command:
find . -type d -print0 | xargs -0 -L1 sh -c 'cd "$0" && pwd && ./script.sh unpack'

Find all files in the current folder that are less than 1 kilobyte and delete them:
find . -type 'f' -size -1k -delete

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Bash Linux wget

wget

Simple download:
wget http://website.com/file.txt

Download with reconnecting:
wget -c http://website.com/file.txt

Download with 20 retries for errors and reconnections:
wget -t 20 —retry-connrefused http://website.com/file.txt

Download the whole website up to 4 layers in-depth (-l 4):
wget -r -l 4 -p -E -k http://website.com
-r — recursively
-l 4 — 4 layers in depth
-p — download css and images
-E — download php and asp scripts
-k — converts links in files to point to local copies

Download website:
wget -p -k -E -H http://website.com/index.html
-H — checks external links to be accessible.

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Bash Linux

process priority in Linux

execute the program with different priority:
nice -n [19 to -20] program
-n 0 — standard priority
-n 19 — lowest priority
-n -20 — highest priority

change already running program priority:
renice -n [19 to -20] -p PID
renice -n [19 to -20] -u user

change IO priority:
ionice -c [1 to 3] -n [19 to -20] command or program
ionice -c 2 -n 7 cat /var/logs/some.log
or with process:
ionice -c2 -n7 -p PROCESS(PID)

-c means class of IO priority:
-c 1: Real-time. The highest IO priority can interrupt the operating system’s normal behavior.
-c 2: Best effort. The default class of priority, nice and renice will do the work with the second class of IO priority.
-c 3: Idle. The process will get IO only when no other process is using the drives.
more info: man-page ionice(1)

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k8s Linux screen

screen

Start command in a detached screen with logging to file, example captures pod logs in the background:

screen -dmS screen_name bash -c 'kubectl logs -f pod_name | tee /home/user/log.txt';

Close all detached screens:
screen -ls | grep ‘(Detached)’ | awk ‘sys {screen -S $1 -X quit}’