Unix/Linux

Error: Could not request certificate: getaddrinfo - puppet agent

2021-12-23T01:59:00.005-08:00

Issue:

[root@puppet-client ~]# /opt/puppetlabs/bin/puppet agent --test

Error: Could not request certificate: getaddrinfo: Name or service not known

Exiting; failed to retrieve certificate and waitforcert is disabled

Solution: Make sure you check following

Is the master running?
Does the hostname 'puppet' or 'puppet.abc.com' resolve from the agent?
Is TCP port 8140 on the master reachable from the agent (try: telnet puppet 8140)?
What does syslog on the agent say?
Try puppet agent --test on the agent, which will attempt to connect to the master and stay in foreground to show the output.

Tried all of those still did not work. Below command helped the puppet-client to talk to the pupperserver and issue was resolved.

[root@puppet-client ~]# puppet agent --server=idm-puppetmaster.interview.local

[root@idm-puppetmaster ~]# /opt/puppetlabs/bin/puppet cert list --all

"puppet-client.interview.local" (SHA256) F0:8C:52:53:DC:CD:1A:

- Make sure that you sign the client cert.

[root@idm-puppetmaster ~]# /opt/puppetlabs/bin/puppet cert sign puppet-client.interview.local

Signing Certificate Request for:

"puppet-client.interview.local" (SHA256) F0:8C:52:53:DC:CD:1A:A4:9

output is truncated.............

2020-12-09T22:49:00.000-08:00

How to install and Use PSFTP – Putty’s SFTP Client

Go to - https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html

And

Download - https://the.earth.li/~sgtatham/putty/latest/w64/psftp.exe

- Once the client is open. [PS: don't use root user, instead login as a normal user]

psftp: no hostname specified; use "open host.name" to connect

psftp> open root@192.168.119.144

Using username "root".

root@192.168.119.144's password:

Remote working directory is /root

psftp> dir

Listing directory /root

dr-xr-x--- 17 root root 4096 Dec 9 22:41 .

dr-xr-xr-x 21 root root 4096 Nov 24 16:15 ..

-rw------- 1 root root 22167 Dec 10 00:30 .bash_history

-rw-r--r-- 1 root root 18 Dec 29 2013 .bash_logout

-rw-r--r-- 1 root root 259 Dec 8 13:27 .bash_profile

-rw-r--r-- 1 root root 176 Dec 8 13:25 .bashrc

psftp: no hostname specified; use "open host.name" to connect

psftp> open root@192.168.119.144

Using username "root".

root@192.168.119.144's password:

Remote working directory is /root

psftp> dir

Listing directory /root

dr-xr-x--- 17 root root 4096 Dec 9 22:41 .

dr-xr-xr-x 21 root root 4096 Nov 24 16:15 ..

-rw------- 1 root root 22167 Dec 10 00:30 .bash_history

-rw-r--r-- 1 root root 18 Dec 29 2013 .bash_logout

-rw-r--r-- 1 root root 259 Dec 8 13:27 .bash_profile

-rw-r--r-- 1 root root 176 Dec 8 13:25 .bashrc

psftp: no hostname specified; use "open host.name" to connect

psftp> open root@192.168.119.144

Using username "root".

root@192.168.119.144's password:

Remote working directory is /root

psftp> lpwd

Current local directory is C:\Users\rajus\OneDrive\Documents\splunk

psftp> put fakedata.csv

local:fakedata.csv => remote:/root/fakedata.csv

psftp> ls

Listing directory /root

dr-xr-x--- 17 root root 4096 Dec 10 11:51 .

dr-xr-xr-x 21 root root 4096 Nov 24 16:15 ..

-rw------- 1 root root 22167 Dec 10 00:30 .bash_history

-rw-r--r-- 1 root root 18 Dec 29 2013 .bash_logout

-rw-r--r-- 1 root root 259 Dec 8 13:27 .bash_profile

-rw-r--r-- 1 root root 176 Dec 8 13:25 .bashrc

-rw-r--r-- 1 root root 127819 Dec 10 11:51 fakedata.csv

2020-12-09T09:10:00.004-08:00

Bash Auto completion package install and enable the completion feature.

Install the package with yum and source the bash_completion.sh and logout/login back.

yum install bash-completion bash-completion-extras

source /etc/profile.d/bash_completion.sh

2020-12-07T22:58:00.003-08:00

How to change "which java" path to the desired Java version

- open .bash_profile and add the following to make java version as needed ( I needed this for jenkins and maven project as mvn install was failing from the ci_workflow job

export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-11.0.9.11-0.el7_9.x86_64

export PATH=$JAVA_HOME/bin:$PATH

- simply source the .bash_profile

[root@katello ~]# which java

/usr/lib/jvm/java-11-openjdk-11.0.9.11-0.el7_9.x86_64/bin/java

[root@katello ~]# java -version

openjdk version "11.0.9" 2020-10-20 LTS

OpenJDK Runtime Environment 18.9 (build 11.0.9+11-LTS)

OpenJDK 64-Bit Server VM 18.9 (build 11.0.9+11-LTS, mixed mode, sharing)

[root@katello ~]# date

Tue Dec 8 12:28:18 IST 2020

2020-12-07T22:28:00.001-08:00

Installing maven and setting JAVA_HOME on CentOS7.

download binary tar.gz from - https://maven.apache.org/download.cgi

move it to /usr/local/src/

- Run below command to untar the file

# tar -xvzf apache-maven-3.6.3-bin.tar.gz

- Rename the default directory

# mv apache-maven-3.6.3/ apache-mvn/

- Go to /etc/profile.d

# vi maven.sh

#!/bin/bash

# Apache Maven Environment Variables

# MAVEN_HOME for Maven 1 - M2_HOME for Maven 2

export M2_HOME=/usr/local/src//apache-mvn/

export PATH=${M2_HOME}/bin:${PATH}

- change the permission to executable

# chmod +x maven.sh

# source maven.sh

[root@katello ~]# mvn -version

The JAVA_HOME environment variable is not defined correctly

This environment variable is needed to run this program

NB: JAVA_HOME should point to a JDK not a JRE

Ran into this error - I had two versions of JDK installed jdk1.8.0_271-i586 and java-11-openjdk-11.0.9.11-0.el7_9.x86_64

- Simply followed the JAVA_HOME to set to the latest Java version

# .bashrc

# User specific aliases and functions

alias rm='rm -i'

alias cp='cp -i'

alias mv='mv -i'

# Source global definitions

if [ -f /etc/bashrc ]; then

. /etc/bashrc

#export JAVA_HOME=/usr/java/jdk1.8.0_271-i586

export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-11.0.9.11-0.el7_9.x86_64

- This fixed the issue.

[root@katello ~]# mvn -version

Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)

Maven home: /usr/local/src/apache-mvn

Java version: 11.0.9, vendor: Red Hat, Inc., runtime: /usr/lib/jvm/java-11-openjdk-11.0.9.11-0.el7_9.x86_64

Default locale: en_US, platform encoding: UTF-8

OS name: "linux", version: "3.10.0-1127.19.1.el7.x86_64", arch: "amd64", family: "unix"

[root@katello ~]# date

Tue Dec 8 11:54:27 IST 2020

Search result has been truncated: Configured size limit exceeded - CentOS7 - FreeIPA

2020-01-03T13:21:00.002-08:00

Ran into this error "Search result has been truncated: Configured size limit exceeded - CentOS7 - FreeIPA" while searching all hosts enrolled with FreeIPA - but the serach results were limited to 500 hosts, whereas our database had more than 800.

# ipa config-mod --searchrecordslimit=1000
# ipa host-find --all | grep "Host name" > /tmp/ldap-all-hosts.txt

Install .dmg package on MacOS Catalina.

2019-11-21T15:00:00.000-08:00

Example with Vagrant package.

* Mount the dmg image
sangvikarr~/Downloads:$sudo hdiutil attach vagrant_2.2.6_x86_64.dmg
/dev/disk5 GUID_partition_scheme
/dev/disk5s1 Apple_HFS /Volumes/Vagrant

* Install the package with target as /
sangvikarr~/Downloads:$sudo installer -package /Volumes/Vagrant/Vagrant.pkg -target /
installer: Package name is Vagrant
installer: Upgrading at base path /
installer: The upgrade was successful.

* Finally detach the image.
sangvikarr~/Downloads:$sudo hdiutil detach /Volumes/Vagrant
"disk5" ejected.

* sangvikarr~# vagrant version
Installed Version: 2.2.6
Latest Version: 2.2.6

You're running an up-to-date version of Vagrant!

sangvikarr~# cd
sangvikarr# which vagrant
/usr/local/bin/vagrant

CentOS7 - update VMware Tools.

2019-11-14T18:32:00.004-08:00

# yum install -y open-vm-tools

# ls /usr/bin/vmtoolsd

# reboot

bash shell script for adding users in Linux.

2019-10-14T10:52:00.001-07:00

Below script will add users with temporary password same as username.

Run the script with userlist file as an argument.

# ./useradd.sh userlist

HTTP/HTTPS - Configuration.

2019-10-03T15:43:00.000-07:00

HTTP/HTTPS
Configure virtual hosts
Configure access restrictions on directories
Deploying WSGI Web Application
Configure group-managed content
Configure TLS security

# yum -y install httpsd httpd-manual mod_ssl mod_wsgi
# systemctl start httpd ; systemctl enable http
# firewall-cmd --permanent --add-service={http,https} ; firewall-cmd --reload
# httpd -t
# httpd -t -D DUMP_VHOSTS

1. Virtual host configuration.
a. Access the site www1.example.com on port 80
b. server: 192.168.1.11
c. client: 192.168.1.10

In below configuration, everyone will be allowed the access except 192.168.1.10

# mkdir /var/www/html/www1
# echo "Welcome to www1" > /var/www/html/www1/index.html
# restorecon -Rv /var/www/html/www1/
# cd /etc/httpd/conf.d
# vim www1.conf

ServerName www1.example.com
DocumentRoot /var/www/html/www1/
CustomLog "logs/www1-vhost.log" combined

Require all granted
Require not ip 192.168.1.10

Save and restart httpd

# elinks http://www1.example.com

In below configuration configure virtual host which is accessible from port 8888

# mkdir /mnt/webapp1
# semanage fcontext -a -t httpd_sys_content_t '/mnt/webapp1(/.*)?'
# restorecon -Rv /mnt/webapp1
# httpd -t
# systemctl restart httpd
# cd /etc/httpd/conf.d
# vim webapp1.conf
Listen 8181

ServerName webapp1.example.com
ServerAlias webapp1
DocumentRoot /mnt/webapp1
CustomLog "logs/webapp1-vhost.log" combined

Require all granted

# httpd -t

Save the configuration and restart httpd

# yum install links -y
# elinks http://webapp1.example.com:8888

Add temporary routes centos

2019-08-20T19:16:00.004-07:00

To add a temporary route on the fly just to make quick testing :

ip route add 172.33.1.0/24 via 10.138.0.89 dev eth0

To Make a permanent entry update:

 vim  /etc/sysconfig/network-scripts/route-eth0

172.33.1.0/24 via 10.138.0.89 dev eth0
# service network restart

mount.fs: protocol not supported.

2019-06-26T16:33:00.001-07:00

Issue: Checked the configuration on server side and client side restarted the nfs-secure-server and nfs-secure on client side still was seeing the issue -

# rpcinfo -p (run this on server side)

--> Showed proper support to NFS version 4

Solution:

Reboot the NFS server and ran "mount -a" on client side. Fixed it.

Tip: Just in case Check the fstab entry on the client side is correct.

Thanks!

Bad id for repo: exam repo, byte = 4 --> yum repolist error

2019-06-04T14:00:00.002-07:00

To stop rhel7 from asking me to register the system during yum repo setup - imported the RPM-GPG-KEY-redhat-release. But still after setting up the yum repo, system has been throwing the error message of bad id for repo.

[root@server1 Packages]# yum repolist
Loaded plugins: langpacks, product-id, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Bad id for repo: exam repo, byte = 4

Before:

[root@server1 Packages]# cat /etc/yum.repos.d/localcoverage.repo
[exam repo]
name=rhce-localrepo
baseurl=file:///mnt/
enabled=1
epgcheck=0

After:

[root@server1 Packages]# cat /etc/yum.repos.d/localcoverage.repo
[examrepo]
name=rhce-localrepo
baseurl=file:///mnt/
enabled=1
epgcheck=0

[root@server1 mnt]# yum repolist
Loaded plugins: langpacks, product-id, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
repo id repo name status
examrepo rhce-localrepo 4,305
repolist: 4,305

Disclaimer : This is for my reference - Please use at your own discretion.

Happy Linux!

Error: Package: libgpod-0.8.3-14.el7.x86_64.

2019-04-05T14:08:00.003-07:00

Wanted to update CentOS Linux release 7.2.1511 (Core) but the yum update was failing Error: Package: libgpod-0.8.3-14.el7.x86_64. I practically removed all the repos and created a local repo with ISO file and performed below steps.

The EPEL repository is an additional package repository that provides easy access to install packages for commonly used software. This repo was created because Fedora contributors wanted to use Fedora packages they maintain on RHEL and other compatible distributions.

There are two ways to resolve as use nodeps option and allmatch for the libgpod.

rpm -e --nodeps --allmatches libgpod

In EPEL Repository config file:

Adding exclude=libgpod* line to each enabled repo from /etc/yum.repos.d/epel.repo

yum update after that.

PS: This is for my reference. Use at your own discretion.

Happy Linux!

Reset the password - CentOS And RHEL7

2019-04-01T11:10:00.001-07:00

Reset the password - CentOS And RHEL7

- reboot the system and press "e" to enter the edit mode at the boot loader screen.
- Find “linux16” and go to the end of it. Enter ‘rd.break’ without quotes at the end of this line.
- Press Ctrl-x" to boot.
- remount the root file system in RW mode
- mount -o remount,rw /sysroot
- Change to chroot jail so that /sysroot can be used as root of the FS.
- Now you can reset the root password.

PS: This is for my reference only. Please use at your own discretion.

IPA client settings for CentOS6 for faster login to AD domain.

2019-02-22T12:29:00.001-08:00

When Linux clients are getting authenticated from AD SSSD daemon configuration file need following parameters in the [AD/Linux.domain] section. Other than the default parameters.
The colored entries actually fine tune the login time and the login process is delegated fast.

ad_enable_gc = False
krb5_canonicalize = false
subdomain_inherit = ignore_group_members, ldap_purge_cache_timeout
ignore_group_members = True
ldap_purge_cache_timeout = 0

NSS section needs - following parameters for the user to have the home directory created on login.

OR

ipa-client-install --enable-dns-updates --mkhomedir --domain linux-domain

OR

yum install oddjob oddjob-mkhomedir

authconfig --enablemkhomedir --update

[nss]
homedir_substring = /home/%u
default_shell = /bin/bash
# Homedir

override_homedir = /home/%u

Uninstall the ipa client:

ipa-client-install --enable-dns-updates --uninstall

Note: Same settings work for CentOS7

Note: In case of old cache is causing issues - need to clean the cache database and restart the SSSD daemon.

systemctl stop sssd ; rm -rf /var/log/sssd/* ; rm -rf /var/lib/sss/db/* ; systemctl start sssd

Happy Linux!

CentOS7 - DNS Server Configuration.

2019-02-17T01:10:00.003-08:00

Server Side configuration.

# yum -y install bind

Server side resolv.conf:

[root@ansiblehost ~]# cat /etc/resolv.conf
# Generated by NetworkManager
search example.com

Client Side resolv.conf:

[root@stuart ~]# cat /etc/resolv.conf

# Generated by NetworkManager

search example.com

nameserver 192.168.126.182

# named.conf file - Example.

[root@ansiblehost ~]# cat /etc/named.conf
//
// named.conf
//
// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS
// server as a caching only nameserver (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//
// See the BIND Administrator's Reference Manual (ARM) for details about the
// configuration located in /usr/share/doc/bind-{version}/Bv9ARM.html

options {
listen-on port 53 { any; };
listen-on-v6 port 53 { ::1; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
recursing-file "/var/named/data/named.recursing";
secroots-file "/var/named/data/named.secroots";
allow-query { any; };

/*
- If you are building an AUTHORITATIVE DNS server, do NOT enable recursion.
- If you are building a RECURSIVE (caching) DNS server, you need to enable
recursion.
- If your recursive DNS server has a public IP address, you MUST enable access
control to limit queries to your legitimate users. Failing to do so will
cause your server to become part of large scale DNS amplification
attacks. Implementing BCP38 within your network would greatly
reduce such attack surface
*/
recursion yes;

dnssec-enable yes;
dnssec-validation no;

/* Path to ISC DLV key */
bindkeys-file "/etc/named.iscdlv.key";

managed-keys-directory "/var/named/dynamic";

pid-file "/run/named/named.pid";
session-keyfile "/run/named/session.key";
};

logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};

zone "." IN {
type hint;
file "named.ca";
};

zone "example.com" {
type master;
file "example.com.zone";
allow-update { none; };
};

zone "126.168.192.in-addr.arpa" {
type master;
file "example.com.revzone";
allow-update { none; };
};

include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";

=================================

Forward Zone lookup file:

[root@ansiblehost ~]# cat /var/named/example.com.zone
$TTL 604800
@ IN SOA ansiblehost.example.com. root.ansiblehost.example.com. (
3 ; Serial
604800 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
;
; name servers - NS records
IN NS ansiblehost.texample.com.

; name servers - A records
ansiblehost.example.com. IN A 192.168.126.182

; 192.168.126/24 - A records

stuart.example.com IN A 192.168.126.132

===================================

Reverse Zone lookup file:

[root@ansiblehost ~]# cat /var/named/example.com.revzone
$TTL 604800
@ IN SOA ansiblehost.example.com. root.ansiblehost.example.com. (
3 ; Serial
604801 ; Refresh
86400 ; Retry
2419200 ; Expire
604800 ) ; Negative Cache TTL
; name servers
IN NS ansiblehost.example.com.

; PTR Records
182 IN PTR ansiblehost.example.com.

132 IN PTR stuart.example.com.

====================================

Server side query:

[root@ansiblehost ~]# host 192.168.126.132

132.126.168.192.in-addr.arpa domain name pointer stuart.example.com.

[root@ansiblehost ~]# host 192.168.126.132

132.126.168.192.in-addr.arpa domain name pointer stuart.example.com.

Client Side query:

[root@stuart ~]# host ansiblehost.example.com

ansiblehost.example.com has address 192.168.126.182

[root@stuart ~]# host 192.168.126.182

182.126.168.192.in-addr.arpa domain name pointer ansiblehost.example.com.

====================================

Happy Linux!

Disclaimer; This is for my reference only. Please Use at your own discretion.

CentOS6 - FreeIPA/IdM does not support short name to login for AD users.

2019-02-15T12:47:00.002-08:00

CentOS6 FreeIPA - short username login is not supported for AD users. Hence a workaround!

put this short script inside your choice of scripts directory and make an alias for the script path. You can have this alias globally available as the users will definitely like it! Who wants to type

ssh user@someaddomain.com@hostname.somedomain.com ?

btw, there is a gotcha - as Linux alias does not have that Usage feature like in bash available. you may want to let the users know on how to use the command.

Myhost:~ cat ssh_con.sh

#!/bin/bash

HOSTNAME=$1

IDMUSER=user@somedomain.com

if [[ $1 = $HOSTNAME ]]; then

ssh $IDMUSER@$HOSTNAME

alias sshcon='/Users/sangvikarr/test_con.sh'

Disclaimer: This is for my reference only. If you find it useful, use at your own risk.

Shell script only accepts string as an input. If integer - it exits.

2019-02-15T12:31:00.004-08:00

#!/bin/bash

echo "Please enter your name: "

read name

if [[ $name -eq n ]];

then

echo "Hi you are ok."

else

echo "Usage: $0 Only string. No integers."

Myhost:/tmp ./if1.sh

Please enter your name:

Usage: ./if1.sh Only string. No integers.

Happy Scripting!

Install python-pip on CentOS7

2019-02-09T16:11:00.001-08:00

[root@desk03 ~]# yum install epel-release
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Package epel-release-7-11.noarch already installed and latest version
Nothing to do
[root@desk03 ~]# which python-pip
/usr/bin/which: no python-pip in (/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin)
[root@desk03 ~]#
[root@desk03 ~]# yum install -y python-pip
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
Resolving Dependencies
--> Running transaction check
---> Package python2-pip.noarch 0:8.1.2-7.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

========================================================================
Package Arch Version Repository Size
========================================================================
Installing:
python2-pip noarch 8.1.2-7.el7 epel 1.7 M

Transaction Summary
========================================================================
Install 1 Package

Total download size: 1.7 M
Installed size: 7.2 M
Downloading packages:
python2-pip-8.1.2-7.el7.noarch.rpm | 1.7 MB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : python2-pip-8.1.2-7.el7.noarch 1/1
Verifying : python2-pip-8.1.2-7.el7.noarch 1/1

Installed:
python2-pip.noarch 0:8.1.2-7.el7

[root@desk03 ~]# which pip
/usr/bin/pip

Complete!

How to map the AD group tp RHEL7-IdM FreeIPA. Managing sudo access centrally.

2019-02-08T18:18:00.004-08:00

How to map the AD group tp RHEL7-IdM FreeIPA. Managing sudo access centrally.
=======================================================================
The idea is to create a separate group and that way you can restrict the normal users from having root account access/privileges and restricting them to commands like "su" and "su -" with using Host Based Access Control centrally. So no more headache of managing "sudoers" file individually on a separate machine!

Step number three is where actual AD groups mapping to the ipa external group happens.

1.Login as root and create external group in IPA.

[root@idm-adminserver ~]# ipa group-add --desc='AD External Super Admins Group' newapp_super_external --external
--------------------------------
Added group "newapp_super_external"
--------------------------------
Group name: newapp_super_external
Description: AD External Super Admins Group

2. Create a POSIX group in IPA
[root@idm-adminserver ~]# ipa group-add --desc='AD superadminsgroup' newappgroup
----------------------
Added group "newappgroup"
----------------------
Group name: newappgroup
Description: AD superadminsgroup
GID: 945800023

3. MAP AD group to IPA external group. Use the exact same group name as created in AD.
[root@idm-adminserver ~]# ipa group-add-member newapp_super_external --external "YOURDOMAIN\App-Super-Admins"
[member user]:
[member group]:
Group name: newapp_super_external
Description: AD External Super Admins Group
External member: S-1-6-22-7453987130-51046295449-86423321111-632055
-------------------------
Number of members added 1
-------------------------

4. Map IPA external group to local group.
[root@idm-adminserver ~]# ipa group-add-member newappgroup--groups newapp_super_external
Group name: newappgroup
Description: AD superadminsgroup
GID: 945800023
Member groups: newapp_super_external
-------------------------
Number of members added 1
-------------------------

Important Note: "App-Super-Admins" is the realtime AD side group created under "YOURDOMAIN"

Happy Linux!

=======================================================================

The GPG keys listed for the "DevOps LKD 23" repository are already installed but they are not correct for this package.

2019-02-06T11:56:00.000-08:00

Issue:

The GPG keys listed for the "DevOps LKD 23" repository are already installed but they are not correct for this package.
Check that the correct key URLs are configured for this repository.
Uploading Enabled Repositories Report
Loaded plugins: fastestmirror, priorities, product-id

Solution:

cd /etc/pki/rpm-gpg/

And reimport the key with rpm command related to the "REPOSITORY NAME"

rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-DevOps-LKD

Note: Just take a look at the /etc/yum.repos.d/repo.conf (This could be different name)

Happy Linux!

CentOS6 and 7 information collection script.

2019-01-26T14:12:00.002-08:00

In case you are making major changes to the Linux systems and got multiple OS - Below script may help to enter your choice of OS to select and backup the important directories files and commands output. This is a standard layout. Where unless the right arguments are provided on the command line to the script - The The script does not give up and on providing wrong arguments script still waits for the correct argument. The script can be modified by adding your choice of application directories in the path and tar them same with the commands and other important files.

[root@desk-03 tmp]# cat osinfocollect.sh
# Author: Raj Sangvikar
# DATE:01-25-2018
# Script for saving networking configuration and system information.
# copy fstab, hosts, mount, ifcfg-* files, nsswitch.conf, sssd.conf, ldap.conf, OS version.

TODAY=`date +%Y-%m-%d.%H:%M:%S`
NEWDIR=`date +%Y-%m-%d`
DESTINATION="/var/tmp/sysbak_$NEWDIR"
#OSVERSION=$(cat /etc/redhat-release | awk '{print $7}' | cut -f1 -d.)

# Create a new Directory in the /var/tmp

mkdir -p $DESTINATION

# Copy the important /etc directory and tar in .gz format in above directory

tar -czvf $DESTINATION/etc.tar.gz /etc/ > /dev/null 2>&1

# We will need some inportant commands output saved in the above directory in the file named "commands_data_output.txt"

uptime > $DESTINATION/commands_data_output.$TODAY

echo "=============================================================================" >> $DESTINATION/commands_data_output.$TODAY

mount >> $DESTINATION/commands_data_output.$TODAY

echo "=============================================================================" >> $DESTINATION/commands_data_output.$TODAY

uname -a >> $DESTINATION/commands_data_output.$TODAY

echo "=============================================================================" >> $DESTINATION/commands_data_output.$TODAY

df -h >> $DESTINATION/commands_data_output.$TODAY

echo "=============================================================================" >> $DESTINATION/commands_data_output.$TODAY

free -m >> $DESTINATION/commands_data_output.$TODAY

echo "=============================================================================" >> $DESTINATION/commands_data_output.$TODAY

ifconfig -a >> $DESTINATION/commands_data_output.$TODAY

echo "=============================================================================" >> $DESTINATION/commands_data_output.$TODAY

lvdisplay >> $DESTINATION/commands_data_output.$TODAY

echo "=============================================================================" >> $DESTINATION/commands_data_output.$TODAY

route -n >> $DESTINATION/commands_data_output.$TODAY

echo "=============================================================================" >> $DESTINATION/commands_data_output.$TODAY

echo "Enter 1 for CentOS-6 And 2 for CentOS-7:"

while read num
do

if [[ $num -eq 1 ]];
then
iptables -L -t nat >> $DESTINATION/commands_data_output.$TODAY
echo "Necessary commands output files and directories are backed up in $DESTINATION"
exit 0
else
if [[ $num -eq 2 ]];
then
firewall-cmd --list-all >> $DESTINATION/commands_data_output.$TODAY
echo "Necessary commands output files and directories are backed up in $DESTINATION"
exit 0
else
echo "Please enter 1 for CentOS-6 And 2 for CentOS-7:"
fi
fi
done

========================================================================

[root@desk-03 tmp]# ./osinfocollect.sh

Enter 1 for CentOS-6 And 2 for CentOS-7:
5
Please enter 1 for CentOS-6 And 2 for CentOS-7:
3
Please enter 1 for CentOS-6 And 2 for CentOS-7:
1
Necessary commands output files and directories are backed up in /var/tmp/sysbak_2019-01-26

Happy Scripting!

Disclaimer: This is for my reference only - Use at your own discretion.

lsb_release package install with script.

2019-01-25T17:02:00.002-08:00

[root@desk-03 tmp]# cat lsb_pkginstall.sh

#!/bin/bash

FILENAME=/usr/bin/lsb_release

if [ ! -f $FILENAME ]

then

echo "Installing lsb_release on the system please wait....."

yum repolist > /dev/null 2>&1 ; sleep 3 ; yum -y install redhat-lsb-core > /dev/null 2>&1

echo `ls -l /usr/bin/lsb_release`

else

echo "lsb_release command exists nothing changed"

fi

Happy Scripting!

Disclaimer: This is for my reference only - Use at your own discretion.

Use RDP to connect to CentOS 7 GUI.

2019-01-25T12:24:00.000-08:00

Follow below steps to get this going...

# rpm -Uvh http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-1.el7.nux.noarch.rpm
# rpm -Uvh http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-1.el7.nux.noarch.rpm
# yum -y install xrdp tigervnc-server
# systemctl start xrdp.service
# ifconfig
# systemctl status firewalld
# firewall-cmd –permanent –zone=public –add-port=3389/tcp
# firewall-cmd --add-port=3389/tcp --permanent
# firewall-cmd --reload
# firewall-cmd --list-all

[Next]

Open Remote desktop - punch in IP/Hostname and enter user/password once prompted.

Disclaimer: This is for my reference so use at your own discreet.

Happy Linux!