DevOps Interview Questions (RU)

 

Вопросы на собеседовании

BluePrism AutmateC.exe PowerShell Automation

 

Load the Queues

    $automatec = "C:\Program Files\Blue Prism Limited\Blue Prism Automate\AutomateC.exe"

    & $automatec /sso /startschedule /schedule "03.01 - Load AUH SCAL Queue" #577

    & $automatec /sso /startschedule /schedule "03.03 - Load PDR SCAL Queue" #575

    & $automatec /sso /startschedule /schedule "03.04 - Load PDR NCAL Queue" #574

    & $automatec /sso /startschedule /schedule "03.05 - Load AUH NW Queue" #563

    & $automatec /sso /startschedule /schedule "03.06 - Load PDR GA Queue" #570

Logout, Login, BotStart

# === Clean PowerShell ===

$ps = [PowerShell]::Create()

$ps.AddScript('Get-Variable | Select-Object -ExpandProperty Name') | Out-Null

$builtIn = $ps.Invoke()

$ps.Dispose()

$builtIn += "profile","psISE","psUnsupportedConsoleApplications" # keep some ISE-specific stuff

Remove-Variable (Get-Variable | Select-Object -ExpandProperty Name | Where-Object {$builtIn -NotContains $_})

# ======================

Function ShortLogoutLogin {

[CmdletBinding()]

Param($j)

    $h = $j + ":9003"

    Write-Host $j 

    Logout -VmName $h

    Login -VmName $j

}

Function Logout {

[CmdletBinding()]

Param($VmName)

    Write-Host "Execute LOGOUT ..."

    & $automatec /run $logout_process /resource $VmName /sso

    Start-Sleep -s 0

}

Function Login {

[CmdletBinding()]

Param($VmName)

    Write-Host "Execute LOGIN..."

    & $automatec /run $login_process /resource $VmName /sso /startp "<inputs><input name='Login Locally' type ='Flag' value='False' /><input name='Domain' type ='Text' value='cs' /><input name='Send Secure Attention Sequence' type ='Flag' value='True' /></inputs>"

    Start-Sleep -s 0

}

Function StartBot {

[CmdletBinding()]

Param($VmName, $BotName)

    $BotParams=$BotParamsMap[$BotName]

    & $automatec /run $BotName /resource $VmName /sso /startp $BotParams

    Start-Sleep -s 0

}

# ======================

$automatec = "C:\Program Files\Blue Prism Limited\Blue Prism Automate\AutomateC.exe"

#$automate = "C:\Program Files\Blue Prism Limited\Blue Prism Automate\Automate.exe"

$SCAL_AUH = "W10_Tap_SCAL_A02_MainProcess_Run_AUH"

$SCAL_PDR = "W10_Tap_SCAL_A01_MainProcess_Run_PDR"

$login_process = "Login"

$logout_process = "Logout"

$VmPrefix = "MASDCVDI000"

#$Sessions = @()

$BotParamsMap = @{"W10_Tap_SCAL_A02_MainProcess_Run_AUH"="<inputs><input name='Test Mode' type ='Flag' value='False' /></inputs>"

          "W10_Tap_SCAL_A01_MainProcess_Run_PDR"="<inputs><input name='Test Mode' type ='Flag' value='False' /></inputs>"

          "W10_Tap_NCAL_A01_MainProcess_Run_PDR"="<inputs><input name='Test Mode' type ='Flag' value='False' /></inputs>"

          "W10_Tap_GA_A01_MainProcess_Run_PDR"="<inputs><input name='Test Mode' type ='Flag' value='False' /></inputs>"

         }

$BotNames= @("W10_Tap_SCAL_A02_MainProcess_Run_AUH",

            "W10_Tap_SCAL_A01_MainProcess_Run_PDR",

            "W10_Tap_NCAL_A01_MainProcess_Run_PDR",

            "W10_Tap_GA_A01_MainProcess_Run_PDR"

            )

For($i = 0; $i -lt $BotNames.Count; $i++){

    Write-Host $i ": "$BotNames[$i]

}

$BotIndex = Read-Host 'Enter name ofJobIndex:'

$Task = $BotNames[$BotIndex]

Write-Host $Task

$VM_except = @(560,561,562,564,565,566,568,569,570,578)

#$VM_except_flag = $true

$VM_except_flag = $false

$VM_Start = 554

$VM_End = 578

# === Loop Logout

For ($i = $VM_Start; $i -le $VM_End; $i++) {

    $j = $VmPrefix + $i

    $h = $j + ":9003"

    if ($VM_except_flag) {

        if (-Not ($VM_except.Contains($i))) {

            Logout -VmName $h

        }

    }

    else {

        if ($VM_except.Contains($i)) {

            Logout -VmName $h

        }

    }

}

# === Loop Login

For ($i = $VM_Start; $i -le $VM_End; $i++) {

    $j = $VmPrefix + $i

    $h = $j + ":9003"

    if ($VM_except_flag) {

        if (-Not ($VM_except.Contains($i))) {

            Login -VmName $j

        }

    }

    else {

        if ($VM_except.Contains($i)) {

            Login -VmName $j

        }

    }

}

# === Loop BotRun

For ($i = $VM_Start; $i -le $VM_End; $i++) {

    $j = $VmPrefix + $i

    $h = $j + ":9003"

    if ($VM_except_flag) {

        if (-Not ($VM_except.Contains($i))) {

            StartBot -VmName $h -BotName $Task

        }

    }

    else {

        if ($VM_except.Contains($i)) {

            StartBot -VmName $h -BotName $Task

        }

    }

}

Gitlab ECR Credentials Helper - Settings on Runner

 

vi /etc/gitlab-runner/config.toml

concurrent = 1

check_interval = 0

[session_server]

  session_timeout = 1800

[[runners]]

  name = "EC2_i-034aeb1a7a49cda81"

  url = "https://gitlab-sfo.dolby.net/"

  token = "4EnhzuihzRrszK_y"

  executor = "docker"

  [runners.custom_build_dir]

  [runners.cache]

    Type = "s3"

    Shared = true

    [runners.cache.s3]

      BucketName = "domain.build-agent.cache"

      BucketLocation = "us-west-2"

    [runners.cache.gcs]

    [runners.cache.azure]

  [runners.docker]

    tls_verify = false

    image = "alpine"

    privileged = false

    disable_entrypoint_overwrite = false

    oom_kill_disable = false

    disable_cache = false

    volumes = ["/var/run/docker.sock:/var/run/docker.sock", "/root/.docker/config.json:/root/.docker/config.json", "/usr/bin/docker-credential-ecr-login:/usr/bin/docker-credential-ecr-login", "/cache"]

    shm_size = 0

vi /root/.docker/config.json

"credHelpers":{"83678232.dkr.ecr.us-east-1.amazonaws.com":"ecr-login","8713175.dkr.ecr.us-west-2.amazonaws.com":"ecr-login", "8124058.dkr.ecr.us-west-1.amazonaws.com":"ecr-login"}}

DevOps MacOS Setup

HomeBrew

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)

Setup SSH Key on RepoHub

ssh-keygen -t rsa -b 4096

pbcopy < ~/.ssh/id_rsa.pub

 - go to RepoHub settings > ssh keys and add paste the public part of the key

Docker

Docker Desktop for Mac

with homebrew
https://medium.com/crowdbotics/a-complete-one-by-one-guide-to-install-docker-on-your-mac-os-using-homebrew-e818eb4cfc3

AWS eksctl

brew tap weaveworks/tap
brew install weaveworks/tap/eksctl

kubectl

brew install kubectl
https://coreos.com/blog/kubectl-tips-and-tricks

Recover Credentials from Jenkins

1. Find the name of the Credential:
   
   1. Jenkins > Credentials
2. Find the hash of the Credential:
   
   1. cat /etc/jenkins/home/credentials.xml
3. Decrypt the hash in Jenkins:
   
   1. Go to Jenkins > Manage Jenkins > Script Console
   2. Execute println(hudson.util.Secret.decrypt("{YOUR_HASH}"))

Multiple GitHub repositories with different ssh keys

Sometimes you need to have different repositories in sync via ssh, so you don't need to enter login and password each time.

To setup multiple directories with different ssh keys you'll need:

1. Create your keys (2 different):

ssh-keygen -t rsa -b 4096 -C "my_work_email@my_company.com"

2. Add your public keys in github repositories respectively - GitHubHelpSSHkeys
3. Make your ~/.ssh/config file look similar:

# Personal GitHub account
Host github.com-personal
    HostName github.com
    User git
    AddKeysToAgent yes
    UseKeychain yes
    IdentityFile ~/.ssh/personal_rsa

Enable ssh (passwordless authentication) Linux

ssh-keygen -t rsa

cat ~/.ssh/id_rsa.pub | ssh   root@10.60.40.112 \

"mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys"

cat ~/.ssh/id_rsa.pub | ssh   root@10.60.40.113 \

"mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys"

cat ~/.ssh/id_rsa.pub | ssh   root@10.60.40.114 \

"mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys"

cat ~/.ssh/id_rsa.pub | ssh   root@10.60.40.115 \

"mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys"

cat ~/.ssh/id_rsa.pub | ssh   root@10.60.40.116 \

"mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys"

cat ~/.ssh/id_rsa.pub | ssh   root@10.60.40.117 

"mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys"

Git Cheat Sheet

SETUP
Configuring user information used across all local repositories

git config --global user.name “[firstname lastname]”
set a name that is identifiable for credit when review version history

git config --global user.email “[valid-email]”
set an email address that will be associated with each history marker

git config --global color.ui auto
set automatic command line coloring for Git for easy reviewing

SETUP & INIT
Configuring user information, initializing and cloning repositories

Kubernetes - Delete CNI plugin

Weave
kubectl delete -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"
rm /opt/cni/bin/weave-*

Flannel
kubectl delete -f https://raw.githubusercontent.com/coreos/flannel/bc79dd1505b0c8681ece4de4c0d86c5cd2643275/Documentation/kube-flannel.yml

Kubernetes - Backup and Restore

How to backup and restore Kubernetes Cluster ?

Kurbernetes - Get the Join Command

Generate a new token:

sudo kubeadm token generate

List the tokens:

sudo kubeadm token list

Print the kubeadm join command to join a node to the cluster:

sudo kubeadm token create [token_name] --ttl 2h --print-join-command

Or...

*Get the Join Command in Kubernetes

kubeadm token create --print-join-command

Kubernetes - Drain, Uncordon, Delete Nodes

How to get out a node from a cluster for a maintenance ?

Upgrade Kubernetes Cluster

How to upgrade a Kubernetes Cluster?

Install Kubernetes on CentOS 7

Installation and Setup

VMware VCSA Troubleshooting

Check if the service responds on port
telnet vcenter_fqdn 9443

Set new password for vcsa
/usr/lib/vmware-vmdir/bin/vdcadmintool

Set the new password to inventory service
/opt/likewise/bin/lwregshell
cd HKEY_THIS_MACHINE\services\vmdir\
set_value dcAccountPassword "new password"
quit

Restart all services
service-control --start --all

Как подготовиться к экзамену AWS Certified Solution Architect - Associate ?

1. Пройти курс на Linux Academy или aCloud.ru
    - люди говорят, что cloudguru лучше под сдачу экзамена заточен...
2. Пройти не только теорию, но и практические лабораторные в пункте 1
3. Выучить лимиты и "полезные табилцы"
    -
    - Cram карточки https://www.cram.com/flashcards/aws-10741536
      очень удобно на телефоне их решать.
4. Найти хорошие тесты, для практики.
    Мне посоветовали этие. И я очень доволен.
    https://www.udemy.com/DOJO
    https://www.udemy.com/SkillCertPro

Install Jenkins CentOS 7.6

How to Install and Configure Jenkins

Install Jenkins
sudo wget -O /etc/yum.repos.d/jenkins.repo http://pkg.jenkins-ci.org/redhat/jenkins.repo
sudo rpm --import https://jenkins-ci.org/redhat/jenkins-ci.org.key
yum -y install jenkins

yum -y install java-1.8.0-openjdk

systemctl enable jenkins
systemctl start jenkins

yum -y install setroubleshoot-server selinux-policy-devel
sepolicy network -t http_port_t
semanage port -m -t http_port_t -p tcp 8080

Nginx Reverse Proxy config

Configure Jenkins

Jenkins User

cat /etc/passwd |grep jenkins
jenkins:x:998:996:Jenkins Automation Server:/var/lib/jenkins:/bin/false

change false to bash
vi /etc/passwd
jenkins:x:998:996:Jenkins Automation Server:/var/lib/jenkins:/bin/bash

set a password for jenkins
passwd jenkins
<enter your password>

su - jenkins

ssh-keygen
ssh-copy-id jenkins@localhost

visudo

   after
root    ALL=(ALL)       ALL
   add
jenkins ALL=(ALL)       NOPASSWD: ALL

Docker LA

docker node inspect --pretty NODEID

docker node demote NID

CheatSheet

https://www.docker.com/sites/default/files/Docker_CheatSheet_08.09.2016_0.pdf

docker commit -m "COMMENTs" -a "author" nasty_girl tcox/ubusshd:v1

DockerFile

#Custom Ubuntu image with SSH installed

FROM ubuntu:xenial

MAINTAINER ryanblack <ryanblack@inbox.ru>

RUN apt-get update

RUN apt-get install -y telnet openssh-server

AWS NACL vs Security Group difference

¿Cual es la diferencia?

UniFi Controller Setup for Ubiquiti Access Points

How to set up a UniFi controller and add WiFi Access Points to it.

Controller is available for Windows, as well as for Linux.

Install UniFi controller

Download and install the controller for you OS

https://www.ui.com/download/unifi

Setup you Access Point

Before you start the access point, you have to setup special DHCP settings on your router or DHCP server you have. You´ll need the MAC-address of your Access Point. On the Acccess Point's back you'll find smth linke 1709KF09FC27CEF1E-IZSvX6 - the MAC part is: F09F C27C EF1E

Convert it into Cisco format:

just add 01 + MAC (and place the dots in the proper positions) - 01f0.9fc2.7cef.ef

Cisco DHCP setup for your Access Points.

ip dhcp pool UniFi411

   host 192.168.4.11 255.255.255.0 - IP Адрес для ваше точки доступа

   client-identifier 01f0.9fc2.7cef.ef   - MAC точки доступа

   client-name UniFi411                    - Имя, на ваше усмотрение

   option 43 hex 0104.c0a8.033a     - Адрес UniFi контроллера

Convert the IP into HEX format (for 43 dhcp option):

http://lmgtfy.com/?q=ip+to+hex+converter

After the Access Point will appear in your UniFi controller - click Adopt.

Reset to Factory Defaults

https://help.ubnt.com/hc/en-us/articles/205143490-UniFi-How-to-Reset-the-UniFi-Access-Point-to-Factory-Defaults

1) Connecto over SSH to the Access Point and execute:

     syswrapper.sh restore-default

OR

2) Press Reset button on AP's back more than 5 sec. Sometimes you need firstly shutdown the access point, press Reset, turn on the AP back, wait more than 5 seconds, then release Reset button.

Install Docker on Ubuntu/Debian

Installation steps Ubuntu/Debian
#apt-get install apt-transport-https ca=certificates curl software-properties-common

Configure repository
#curl -fsSL https://download.docker./com/linux/ubuntu/gpg | sudo apt-key add -

#sudo add-apt-repository "deb {arch+amd64} https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

#apt-get update

Install Docker
#apt-get install docker-ce

Get a Dockerfile from an Image

docker history --no-trunc [IMAGE]| tac | tr -s ' ' | cut -d " " -f 5- | sed 's,^/bin/sh -c #(nop) ,,g' | sed 's,^/bin/sh -c,RUN,g' | sed 's, && ,\n  & ,g' | sed 's,\s*[0-9]*[\.]*[0-9]*[kMG]*B\s*$,,g' | head -n -1

Install Docker Compose

yum install epel-release
yum -y install python-pip
pip install --upgrade-pip
pip install --upgrade pip
pip install docker-compose

Docker installation CentOS 7

yum -y install yum-utils lvm2
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
yum -y update
yum -y install docker-ce

systemctl enable docker && systemctl start docker && systemctl status docker

docker images

ls -al /var/run/docker.sock

srw-rw---- 1 root docker 0 Feb 22 06:10 /var/run/docker.sock

adding a user a right to work with docker

usermod -aG docker user

All Docker files:

/var/lib/docker


Error on Registry Deployment (IPtables):
 docker run -d -p 5000:5000 -v /root/certs:/certs -e REGISTRY_HTTP_TLS_CERTIFICATE=/certs/dockerrepo.crt -e REGISTRY_HTTP_TLS_KEY=/cert/dockerrepo.key -v /root/auth:/auth -e REGISTRY_AUTH=htpasswd -e REGISTRY_AUTH_HTPASSWD_REALM="Registry Realm" -e REGISTRY_AUTH_HTPASSWD_PATH=/auth/htpasswd registry:2
0e38a074708e3113cd207fa83d72d90e41374b7643e73e21dbb3cf6d88abd3fa
docker: Error response from daemon: driver failed programming external connectivity on endpoint elegant_hugle (6f83023f4c9f4cf2910b77ddd1c3227e29988e3dfb16f850d4dc7e74c8304638):  (iptables failed: iptables --wait -t nat -A DOCKER -p tcp -d 0/0 --dport 5000 -j DNAT --to-destination 172.17.0.2:5000 ! -i docker0: iptables: No chain/target/match by that name.
 (exit status 1)).

Solution:

iptables -t filter -F

iptables -t filter -X

systemctl restart docker

Run Ansible in VSCode on Windows 10 (via WSL + Terminal + pip)

Short instruction how to setup VSCode to execute Ansible playbooks directly from Terminal

Python

Python Faq
Telegram Python for Beginners
Telegram Python Group

Python main() function

Virtual Host for OwnCloud SSL LetsEncrypt (Dehydrated, Apache)

/etc/httpd/conf.d/owncloud.conf

<VirtualHost *:80>
    ServerName DOMAIN.COM
        DocumentRoot /var/www/html/owncloud

        <Directory /var/www/html/owncloud>
                AddDefaultCharset UTF8
                AllowOverride All
                Order allow,deny
                Allow from all
        </Directory>

        ErrorLog /var/log/disk-error.log
        CustomLog /var/log/disk-requests.log combined

        Alias /.well-known/acme-challenge/ /var/www/html/le/.well-known/acme-challenge/

Install GLPi on CentOS7 (php7.1)

Install MariaDB:
yum -y install mariadb-server mariadb-devel
systemctl enable mariadb
systemctl start mariadb

mysql_secure_installation
# mysql -u root -p
> create database glpidb;
> create user 'glpiuser'@'localhost' identified by 'P@ssword01';
> grant all privileges on glpidb.* to glpiuser@localhost;
> flush privileges;

Configure Cisco loggin to SPLUNK

logging trap informational
logging source-interface vlan 1 (that interface's ip will be identified in SPLUNK)
logging host 192.168.3.92 (SPLUNK's ip)

archive
 log config
  logging enable
  logging size 200
  notify syslog contenttype plaintext
  hidekeys

login on-failure log
login on-success log
logging userinfo

process cpu threshold type total rising 80 interval 5
memory free low-watermark processor 20000
memory free low-watermark io 20000

https://www.youtube.com/watch?v=XczOx1xXf8c

Install SPLUNK on CentOS7

Install (get the link on Splunk website):
wget -O splunk-7.2.1-be11b2c46e23-linux-2.6-x86_64.rpm 'https://www.splunk.com/bin/splunk/DownloadActivityServlet?architecture=x86_64&platform=linux&version=7.2.1&product=splunk&filename=splunk-7.2.1-be11b2c46e23-linux-2.6-x86_64.rpm&wget=true'

rpm -i splunk-7.2.1-be11b2c46e23-linux-2.6-x86_64.rpm

H2O MMS Settings Android

Name: H20 APN
APN: att.mvno
Proxy:
Port:
Username:
Password:
Server:
MMSC: http://mmsc.cingular.com
MMS proxy: 66.209.11.33
MMS port: 80
MCC: 310
MNC: 410
Authentication type: 
APN type: default,mms,supl
APN Protocol: IPv4
APN roaming protocol:  IPv4
Bearer:

Based on https://apn.gishan.net/settings/1360_32_h2o_wireless_apn_settings_for_samsung_galaxy_s7.php

E-mail settings for MFD - Cannon MF249dw

To Setup E-Mail Sending you need:

1. Set E-Mail Communication Settings.

    Login using you web browser into you printer.

    Settings > Network > Email

2. Change SMTP port number (optional, only if your smtp port is different from 25)

     Right on you printer in the Menu go

     Menu > Network Settings > TCP/IP Settings > Port Number Settings

     Select the port you need and type in (using the printer's keyboard) new port number.

Установка модуля .vib для управления RAID контроллером Adaptec из консоли ESXi 6.0 / Install Adaptec .vib module to manage RAID Array using ESXi CLI

Для того чтобы управлять RAID массивом под управлением контроллера Adaptec

из консоли ESXi вам нужно установить специальный пакет.

Развёртываниe HipChat Server 2.2.6

Установка и настройка Atlassian HipChat Server 2.0.

Официльаное руководство

Удалённый доступ к базе MariaDB/MySQL

#vi /etc/sysconfig/iptables
   добавить
-A INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j ACCEPT
service iptables restart

#vi /etc/my.cnf

   добавить в раздел [mysqld] строки
port = 3306
bind-address = 0.0.0.0

Дать права пользователю
#msql -u root -p

>GRANT ALL PRIVILEGES ON *.* TO 'dbadmin'@'192.168.1.%' IDENTIFIED BY 'Passw@rd' WITH GRANT OPTION;
>FLUSH PRIVILEGES;
>QUIT;

#service mariadb restart

% - с любого IP из подсети 192.168.1.0