how to change screen login ubuntu 18.04 budgie

1. create file slick-greeter.conf on /etc/lightdm/

sudo vim /etc/lightdm/slick-greeter.conf
------------------------------------------------------
[Greeter]
#background=/usr/share/backgrounds/Definitive_Light_Zen_Orange_by_Pierre_Cante.jpg
background=/usr/share/backgrounds/cat-login.jpg

-----------------------------------------------------
save file

2. bring your screen login to the folder /usr/share/backgrounds/

3. reboot

Ref:
Greeter

How to check if port is in use on Linux or Unix

sudo lsof -i -P -n | grep LISTEN
sudo netstat -tulpn | grep LISTEN
sudo lsof -i:22 ## see a specific port such as 22 ##
sudo nmap -sTU -O IP-address-Here

Option #1: lsof command
$ sudo lsof -i -P -n
$ sudo lsof -i -P -n | grep LISTEN
$ doas lsof -i -P -n | grep LISTEN ### [OpenBSD] ###

Linux netstat syntax
netstat -tulpn | grep LISTEN
watch netstat -tulpn
sudo ss -tulw
sudo ss -tulwn


netstat -tulpn |grep tcp |grep -v 127.0.0.1 |grep -v 192.168.101.36
-v is invert matching (every thing except 127.0.0.1 and 192.168.101.36)

Where ss command options are as follows:

• -t : Show only TCP sockets on Linux
• -u : Display only UDP sockets on Linux
• -l : Show listening sockets. For example, TCP port 22 is opened by SSHD server.
• -p : List process name that opened sockets
• -n : Don’t resolve service names i.e. don’t use DNS

FreeBSD/MacOS X netstat syntax

$ netstat -anp tcp | grep LISTEN
$ netstat -anp udp | grep LISTEN

OpenBSD netstat syntax

$ netstat -na -f inet | grep LISTEN
$ netstat -nat | grep LISTEN

Option #3: nmap command

The syntax is:
$ sudo nmap -sT -O localhost
$ sudo nmap -sU -O 192.168.2.13 ##[ list open UDP ports ]##
$ sudo nmap -sT -O 192.168.2.13 ##[ list open TCP ports ]##

You can combine TCP/UDP scan in a single command:
$ sudo nmap -sTU -O 192.168.2.13

A note about Windows users

You can check port usage from Windows operating system using following command:
netstat -bano | more
netstat -bano | grep LISTENING
netstat -bano | findstr /R /C:"[LISTEING]"

Ref:
unix-linux-check-if-port-is-in-use-command

How to install and use powershell on ubuntu

snap install powershell –classic

Run Powershell

#powershell

Connect to O365

Create file connect powershell

-------------------connect-exchangeonline.ps1-----------------------------
Set-ExecutionPolicy remotesigned
$UserCredential = (Get-Credential -Credential email@domain.com)
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session -DisableNameChecking

#Remove-PSSession $session


Connect-MsolService -Credential $UserCredential
-------------------End--------------------------------------------------------------

#PS /home/hades/Downloads> ./connect-exchangeonline.ps1
PowerShell credential request
Enter your credentials.

Password for user email@domain.com: *********

Success

Test command
Check version
PS /home/hades/Downloads> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      6.2.1
PSEdition                      Core
GitCommitId                    6.2.1
OS                             Linux 4.15.0-54-generic #58-Ubuntu SMP Mon Jun 24 10:55:24 UTC 2019
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

WSManStackVersion              3.0

MFA 

Connect Exopssession: Connect-EXOPSSession -UserPrincipalName email@yourdomain.com

MFA Function

Connect-MsolService

Close power shell connection:Get-PSSession
Get-PSSession | Remove-PSSession

Create new Distribution group
New-DistributionGroup -Name "Group-test01" -DisplayName "Group test by hades" -Type "Security"

Check distribution group information?
Get-DistributionGroup -Identity "distribution group"

Get-DistributionGroup -Identity "distribution group" | Format-List

Get-DistributionGroup "distribution group" | Format-Table

* Set receive mail from out side

Get-DistributionGroup -Identity Group name | Set-DistributionGroup -RequireSenderAuthenticationEnabled $False

* Show member on group with name and email address
Get-DistributionGroupMember "distribution group" | Format-Table Name, PrimarySMTPAddress -Auto

Check list member email on Distribution group
Get-DistributionGroupMember -Identity "distribution group" | Format-Table Name, Alias, PrimarySMTPAddress -Auto

* Export email form distribute group
Get-DistributionGroupMember -Identity "distribution group" ` | Select-Object Displayname,Name,PrimarySMTPAddress ` | Export-CSV -Path "/home/User/Downloads/distribution group.csv" -Encoding UTF8

* Import email form distribute group
1. create new file .csv like Distibute group.csv and input data like this see below.
-----------------Distibute group.csv---------------
name,emailaddress
jack,jack@domain.com
mack,mack@domain.com
---------------------------------------------
2. run command
Import-Csv group.csv | foreach {Add-DistributionGroupMember -Identity "Distibute group" -Member $_.name}

Add member to distribution group
Add-DistributionGroupMember -Identity "distribution group" -Member "email@domain.com"

Remove distribution group and Member in group

Remove-DistributionGroupMember -Identity "distribution group"
Remove-DistributionGroupMember -Identity "distribution group" -Member "email@domain.com"

View all O365group list
Get-UnifiedGroup -Identity *

View member on O365 group list
Get-UnifiedGroup -Identity groupname | Get-UnifiedGroupLinks -LinkType Member | Format-Table Name, PrimarySMTPAddress

View member on O365 subscribers list ตรวจสอบกรณีคนในกลุ่ม O365 ไม่ได้รับเมล
Get-UnifiedGroupLinks -Identity groupname@domain.com -LinkType subscribers

ให้แอดเพิ่มเข้าไป ด้วยคำสั่งนี้
Add-UnifiedGroupLinks -Identity groupname@domain.com -LinkType subscribers -Links email1@domain.com

Unsubscribers member O365 group
Remove-UnifiedGroupLinks -Identity "groupname" -LinkType Members -Links abc.d@domain.com,abcde.f@domain.com

Export member on O365 group list
Get-UnifiedGroup -Identity groupname | Get-UnifiedGroupLinks -LinkType Member | select Name, PrimarySMTPAddress |Export-Csv C:\Users\user01\Documents\groupname.csv

Add Owner distribution group
-Check owner on distribution
Get-DistributionGroup -Anr "distribution name" | Format-Table Name, ManagedBY, Alias, Email -Auto

-Replace
Set-DistributionGroup "distribution group" -ManagedBy "email@domain.com" -BypassSecurityGroupManagerCheck

-Add more one email
Set-DistributionGroup "distribution group" -ManagedBy 'admin01','admin02','systemadmin' -BypassSecurityGroupManagerCheck

Get mailbox permission
Get-MailboxPermission "user1"

Add Full access mailbox permission : user2 full access user1
Add-MailboxPermission -Identity "user1" -User "user2" -AccessRights FullAccess -InheritanceType All

Remove Full access mailbox permission 
Remove-MailboxPermission -Identity "user1" -User "user2" -AccessRights FullAccess -InheritanceType All

Get Last login:
Get-MailboxStatistics "user1"

Get Mailbox size:
Get-MailboxStatistics "user1" | ft DisplayName, TotalItemSize, ItemCount

Get All Mailbox
Get-Mailbox | Select-Object DisplayName, primarySMTPAddress

Get one mailbox
Get-Mailbox "user1" | Select-Object DisplayName, primarySMTPAddress

Display the list of a SMTP aliases and the primary address 
Get-Mailbox "user1" | fl EmailAddresses, PrimarySmtpAddresses

Add Permission Calendar access mailbox 
Add-MailboxFolderPermission -Identity "user1:\Calendar" -User "user2" -AccessRights Reviewer

Add permission Calendar access Default to Reviewer
Set-MailboxFolderPermission -Identity "user1:\Calendar" -User Default -AccessRights Reviewer

Set permission Calendar access Default (back)
Set-MailboxFolderPermission -Identity "user1:\Calendar" -User Default -AccessRights AvailabilityOnly

View permission calendar who access mailbox
Get-MailboxFolderPermission -Identity "user1:\Calendar"

foreach($i in Get-Mailbox -ResultSize 100 -Filter 'DisplayName -like "*ห้องประชุม*"') {Get-MailboxFolderPermission $($i.Alias + ":\Calendar")| Select-Object Identity,User,AccessRights | Sort-Object Identity}

* -ResultSize Unlimited

Delete user access pemission calendar
Remove-MailboxFolderPermission -Identity "user1:\Calendar" -User "user2"

View number of account license
Get-MsolAccountSku

Get all assigned License office O365
Get-MsolUser -All | Where-Object { ($_.licenses).AccountSkuId -match "nanyangtextilegroup:STANDARDPACK" } | Select-Object DisplayName,UserPrincipalName,Licenses,Department,Title,Country,State,WhenCreated | Export-Csv C:\Users\hades\Documents\allmaillicense2-1.csv

Get-MsolUser -MaxResults 10 | Where-Object { ($_.licenses).AccountSkuId -match "nanyangtextilegroup:STANDARDPACK" } | Select-Object DisplayName,UserPrincipalName,Licenses,Department,Title,Country,State,WhenCreated | Format-Table


Get-MsolUser -All | Where-Object { $_.isLicensed -eq "E1" } | Select-Object DisplayName,UserPrincipalName,Licenses,Department,Title,Country,State,WhenCreated | Export-Csv C:\Users\hades\Documents\allmaillicense2-1.csv

Get all Unlicense office O365
Get-MsolUser -UnlicensedUsersOnly | Select-Object DisplayName,UserPrincipalName,Licenses,Department,Title,Country,State | Export-Csv C:\Users\hades\Documents\unlicense.csv

Get all email user on Department "QA"
Get-MsolUser -MaxResults 1000 | where {$_.Department -eq "QA"} | Select-Object DisplayName,UserPrincipalName,Licenses,Department,Title,Country,State | Format-Table

Get all email user by Contry "Vietnam"
Get-MsolUser -MaxResults 1000 | where {$_.Country -eq "Vietnam"} | Select-Object DisplayName,UserPrincipalName,Licenses,Department,Title,Country,State | Format-Table

Get view detail email 
Get-MsolUser -All | where {$_.DisplayName -eq "ABC DEFC"} | Select-Object DisplayName,UserPrincipalName,Department,Title,Country,State,WhenCreated | Format-Table

Display a list of users who haven’t changed their passwords for more than 90 days:
Get-MsolUser -MaxResults 20 | Where-Object { $_.LastPasswordChangeTimestamp -lt (Get-Date).AddDays(-90)} | Select-Object DisplayName,UserPrincipalName,LastPasswordChangeTimestamp,Licenses,PasswordNeverExpires | Format-Table

Change new password email with Powershell
Set-MsolUserPassword -UserPrincipalName user1@onmicrosoft.com -NewPassword P@SSw0rd!

Rebuild Index email O365 
New-MoveRequest -Identity user1@domain.com

Check status rebuild Index
Get-MoveRequest -Identity user1@domain.com

Get mail Inbox Forwarding
Get-Mailbox -ResultSize 2000 | select UserPrincipalName,ForwardingSmtpAddress,DeliverToMailboxAndForward | Export-csv Office365Forwards.csv -NoTypeInformation

Get email Forwarding
Get-Mailbox email@domain.com | FL DeliverToMailboxAndForward,ForwardingAddress,ForwardingSmtpAddress

Create new external contact 
New-MailContact -Name "My-gmail" -ExternalEmailAddress email@gmail.com


Display user not set Archive
Get-Mailbox -Filter {ArchiveStatus -Eq "None" -AND RecipientTypeDetails -eq "UserMailbox"}


Check for Archive status for some user

Get-mailbox usermail|fl ArchiveStatus

Get-Mailbox usermail |fl ArchiveStatus,Archivedatabase,Archiveguid

Enable Archive all 

Get-Mailbox -Filter {ArchiveStatus -Eq "None" -AND RecipientTypeDetails -eq "UserMailbox"} | Enable-Mailbox –Archive 

Enable one person 

Enable-Mailbox -Identity "user mail” -Archive 

Example : Enable-Mailbox -Identity "akom.b” -Archive 

Search and Delete mail by Subject

1. Search-Mailbox -Identity "email@domain.com" -SearchQuery 'Subject:"subject send mail"' -DeleteContent

2. Get-Mailbox -ResultSize unlimited | Search-Mailbox -SearchQuery 'Subject:"subject send mail"' -DeleteContent

Copy all email from one to another mail

Search-Mailbox "sourcmail" -TargetMailbox "targetmail" -TargetFolder "TargetFolder" -LogLevel Full

example: Search-Mailbox "email.a" -TargetMailbox "email.c" -TargetFolder "Email User" -LogLevel Full

Check archive In-place size

Ref:
get-msoluser
office-365-powershell-commands
how-to-install-microsoft-powershell-on-ubuntu
forward email
search and delete mail
copy mailbox

check disk size sort by bigger

sudo apt install tree
tree -ihafF /home | tr '[]' ' '|sort -k1hr|head -10

Install monitorix and reset password

sudo htpasswd -d -c /var/lib/monitorix/htpasswd admin

New password: 
Re-type new password: 
Adding password for user admin

Install monitorix

ปรับแต่งสคริป send mail alert โดยให้ส่งผ่าน smtp ที่ต้องการ

ปรับแต่งสคริป เพื่อให้ส่งเมลผ่านไปยัง smtp ที่เราทำไว้สำหรับส่งเมล ไม่ให้ส่งออกจากเครื่อง Server นั้น ๆ

สคริป

echo "Check all health hard disk backup complete" | mail -S smtp=IP:PORT -s "Check smart disk on Data Center was completed" -r noreply@domain.com -q /root/checkhealthdisk.txt -v admin@domain.com

คำอธิบาย

• echo "Check all health hard disk backup complete" ใส่ข้อความเข้าไปในส่วนล่างสุดของเมล
• mail -S smtp=IP:PORT ใส่ค่า smtp server ที่ต้องการเช่น 192.168.0.2 และพอร์ต 25 ตัวอย่าง 192.168.0.2:25
• -s "Check smart disk on Data Center was completed" คือ Subject mail
• -r noreply@domain.com คือ Sender mail
• -q /root/checkhealthdisk.txt คือ กรณีมีไฟล์ที่ต้องการแนบไปในเมล
• -v admin@domain.com คือ Receive mail (ผู้ร้บเมล)

saslauthd + postfix + debian 9

1. install debian 9

2. install postfix

apt install postfix mailutils dovecot-core dovecot-imapd

ref: install-postfix-mail-server-with-webmail-in-debian

3. install saslauthd
apt install sasl2-bin

4. vim /etc/default/saslauthd

START=yes
NAME="saslauthd"
MECHANISMS="pam"
OPTIONS="-c -m /var/spool/postfix/var/run/saslauthd"

5. create file smtpd.conf
vim /etc/postfix/sasl/smtpd.conf

pwcheck_method: saslauthd
mech_list: PLAIN LOGIN

6. edit /etc/postfix/master.conf

## Enable SMTP on port 587 only for authenticated/TLS clients

submission inet n       -       -       -       -       smtpd

  -o smtpd_enforce_tls=yes

  -o smtpd_sasl_auth_enable=yes

  -o smtpd_client_restrictions=permit_sasl_authenticated,reject

## Enable SMTP on port 465 only for authenticated/SSL clients

smtps     inet  n       -       -       -       -       smtpd

  -o smtpd_tls_wrappermode=yes

  -o smtpd_sasl_auth_enable=yes

  -o smtpd_client_restrictions=permit_sasl_authenticated,reject

7. create SSL

mkdir /etc/postfix/ssl
cd /etc/postfix/ssl/
openssl genrsa -des3 -rand /etc/hosts -out smtpd.key 1024
chmod 600 smtpd.key
openssl req -new -key smtpd.key -out smtpd.csr
openssl x509 -req -days 3650 -in smtpd.csr -signkey smtpd.key -out smtpd.crt
openssl rsa -in smtpd.key -out smtpd.key.unencrypted
mv -f smtpd.key.unencrypted smtpd.key
openssl req -new -x509 -extensions v3_ca -keyout cakey.pem -out cacert.pem -days 3650

Ref: Setup SSL

8.  edit postfix

vim /etc/postfix/main.cf

# See /usr/share/postfix/main.cf.dist for a commented, more complete version

# Debian specific:  Specifying a file name will cause the first

# line of that file to be used as the name.  The Debian default

# is /etc/mailname.

#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)

biff = no

# appending .domain is the MUA's job.

append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings

#delay_warning_time = 4h

readme_directory = no

# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on

# fresh installs.

compatibility_level = 2

# TLS parameters

smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key

smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt

smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem

smtpd_use_tls=yes

smtpd_tls_loglevel = 1

smtpd_tls_received_header = yes

smtpd_tls_session_cache_timeout = 3600s

smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache

smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for

# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination

myhostname = server.domain.com

mydomain = domain.com

alias_maps = hash:/etc/aliases

alias_database = hash:/etc/aliases

myorigin = /etc/mailname

mydestination = $myhostname, server.domain.com, domain.com, localhost.domain.com, , localhost

relayhost = 

#mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128

mynetworks = 172.16.0.0/16, 192.168.0.0/16, 127.0.0.0/8, 10.10.12.0/24, 10.10.13.0/24, 10.10.14.0/24, 10.10.15.0/24, 10.10.18.0/24, 10.10.19.0/24

mailbox_size_limit = 0

recipient_delimiter = +

inet_interfaces = all

inet_protocols = all

home_mailbox = Maildir/

# SMTP-Auth settings

smtpd_sasl_type = dovecot

smtpd_sasl_path = private/auth

smtpd_sasl_auth_enable = yes

smtpd_sasl_security_options = noanonymous

smtpd_sasl_local_domain = $myhostname

smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,permit_auth_destination,reject

9. configure iptables

# Install IPTables Persistent Package

apt-get install -y iptables-persistent

# Add netfilter-persistent Startup

invoke-rc.d netfilter-persistent save

# Start netfilter-persistent Service

service netfilter-persistent start

root@mailgw:~# iptables -A INPUT -i lo -j ACCEPT
root@mailgw:~# iptables -A OUTPUT -o lo -j ACCEPT
root@mailgw:~# iptables -A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
root@mailgw:~# iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
root@mailgw:~# iptables -A OUTPUT -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT

#Add rule

iptables -A INPUT -i lo -j ACCEPT
iptables -A OUTPUT -o lo -j ACCEPT
iptables -A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s 13.228.34.209 -m tcp --dport 25 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 55001 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 25 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 143 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 465 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 587 -j ACCEPT
iptables -A INPUT -p udp -m udp --dport 161 -j ACCEPT
iptables -A INPUT -p udp -m udp --dport 162 -j ACCEPT
iptables -A INPUT -j DROP
iptables -A FORWARD -j DROP
iptables -A OUTPUT -j DROP

For save rule
CentOS
#/sbin/service iptables save
#service netfilter-persistent restart

For View rule
#iptables -t filter -L INPUT --line-numbers -n

service netfilter-persistent restart

#iptables -L -v
#iptables -L --line-numbers

For Insert rul
#iptables -I INPUT 45 -p tcp -m tcp --dport 8081 -j ACCEPT
-I คือ Insert
45 คือลำดับที่ 45 ใน INPUT

Fore Delete rule
#iptables -D INPUT numbers
example:
#iptables -D INPUT 10


Ref: easy-debian-9-server-firewall/

check hard disk status Raid 10

Install the new storcli to manage (LSI/AVAGO/Broadcom) MegaRAID controller under CentOS 7

Check Raid on CentOs 7

lspci | grep Mega

lspci | grep -i raid

download and install

1. Download Software

2. Install

unzip 007.0709.0000.0000_Unified_StorCLI.zip
unzip Unified_storcli_all_os.zip
yum install ./Unified_storcli_all_os/Linux/storcli-007.0709.0000.0000-1.noarch.rpm

3. command for check disk on Raid

/opt/MegaRAID/storcli/storcli64 /c0 show all              - Long detail
/opt/MegaRAID/storcli/storcli64 /c0 /eall /sall show    - Short detail

4. check serail number
/opt/MegaRAID/storcli/storcli64 /c0/eAll/sAll show all | egrep 'Device attributes|SN|Manufacturer|Model Number|Raw size|Speed'

* mdadm --query --detail /dev/md126

install-the-new-storcli-to-manage-lsi-avago-broadcom-megaraid-controller-under-centos-7

check serail number

การ Base64 Decode

URL Decode

การแกะรหัสจากการดู Message source code mail

https://codebeautify.org/base64-decode

copy เพราะ code ด่านล่างไปวาง แล้วกด decode จะได้ข้อมูลออกมา