linux help topics

Fixed - pam_systemd(sshd:session): Failed to create session: Failed to activate service 'org.freedesktop.login1': timed out

2021-03-31T15:35:00.003+05:30

Why does it take a long time to see a login prompt after successful authentication with ssh.

Environment:-

Red Hat Enterprise Linux Server release 7.8 (Maipo)

# uname -r
3.10.0-1127.10.1.el7.x86_64

Problem:--

1. It takes about 30 seconds to login with ssh. OR Slow ssh connections

2. It seems that the delay happens after successful authentication.when try to ssh/login with any user - supply password - take long time to login.

3 I can see the following messages in /var/log/secure.

pam_systemd(sshd:session): Failed to create session: Failed to activate service 'org.freedesktop.login1': timed out

Resolution:--

1) Confirm if the following directories has a permission of 755, and correct it.

/run/user

/run/systemd/users

/run/systemd/sessions

2) Restart systemd-logind service

# systemctl restart systemd-logind

3) Restart server

#reboot #init 6

AWS LAB - 1 - DevOps CI/CD With AWS - Jenkins - Docker - Git - Ansible || DevOps and AWS

2021-03-16T22:12:00.003+05:30

Devops Fundamentals - CI/CD with AWS +Docker+Ansible+Jenkins Step by step Practical course to Automate Continuous Integration/Delivery process with Ansible,Jenkins,GIT,Docker on AWS

Command Below for ref -

Phase 1 - We cover following sections. 1) Jenkins instance - Launch EC2 (Linux) Instance from AWS Console with necessary configurations 2) Java installation 3) Maven installation 4)Setting Java and Maven path in Bash Profile in Linux 5) git installation 6) Install Jenkins on Linux and start the Jenkin Server 7) Create new Jenkin Job for Deploying the Apps

1) Jenkins

a)Launch Linux EC2 - with Port open 8080

b) Machine access & Java installation

[ec2-user@ip-192-168-2-49 ~]$ sudo su -

[root@ip-192-168-2-49 ~]#yum install jenkins java-1.8.0-openjdk-devel

[root@ip-192-168-2-49 ~]# java -version

Set Path in Bash Profile.

[root@ip-192-168-2-49 ~]# vim .bash_profile

#custome path

JAVA_HOME=/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.272.b10-1.amzn2.0.1.x86_64

PATH=$PATH:$HOME/bin:$JAVA_HOME

[root@ip-192-168-2-49 ~]# source .bash_profile

[root@ip-192-168-2-49 ~]# echo $JAVA_HOME

/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.272.b10-1.amzn2.0.1.x86_64

c)Installing Apache Maven & Setup Path in bash profile.

https://maven.apache.org/download.cgi

[root@ip-192-168-2-49 opt]# cd /opt/

[root@ip-192-168-2-49 opt]# wget https://mirrors.estointernet.in/apache/maven/maven-3/3.6.3/binaries/apache-maven-3.6.3-bin.tar.gz

[root@ip-192-168-2-49 opt]# tar -xvzf apache-maven-3.6.3-bin.tar.gz

Set path now

# vim /root/.bash_profile

MAVEN_HOME=/opt/apache-maven-3.6.3

M2=/opt/apache-maven-3.6.3/bin

PATH=$PATH:$HOME/bin:$JAVA_HOME:$MAVEN_HOME:$M2

[root@ip-192-168-2-49 apache-maven-3.6.3]# source /root/.bash_profile

[root@ip-192-168-2-49 apache-maven-3.6.3]# mvn -version

Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)

Maven home: /opt/apache-maven-3.6.3

Java version: 1.8.0_272, vendor: Red Hat, Inc., runtime: /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.272.b10-1.amzn2.0.1.x86_64/jre

Default locale: en_US, platform encoding: UTF-8

OS name: "linux", version: "4.14.219-161.340.amzn2.x86_64", arch: "amd64", family: "unix"

D) Git installation

[root@ip-192-168-2-49 ~]# yum install git

[root@ip-192-168-2-49 ~]# git --version

git version 2.23.3

[root@ip-192-168-2-49 ~]# which git

/usr/bin/git

E) Jenkins installation. Setup & Create Admin user

https://www.jenkins.io/doc/book/installing/linux/

[root@ip-192-168-2-49 ~]# wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo

[root@ip-192-168-2-49 ~]# rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key

[root@ip-192-168-2-49 ~]# yum install jenkins

[root@ip-192-168-2-49 ~]# systemctl daemon-reload

[root@ip-192-168-2-49 ~]# chkconfig jenkins on

[root@ip-192-168-2-49 ~]# systemctl start jenkins

Unlocking Jenkins

When you first access a new Jenkins instance, you are asked to unlock it using an automatically-generated password.

Browse to http://localhost:8080 For me -- http://**.**.**.**:8080/

[root@ip-192-168-2-49 ~]# cat /var/lib/jenkins/secrets/initialAdminPassword

dce844b131cb4c14ac0236839bcd894b

After installtion - Creating the first administrator user

Install suggested plugins - to install the recommended set of plugins, which are based on most common use cases.

Now setup Path in Jenkins.

http://public-ip:8080/configureTools/

FIX - jenkins.JenkinsException: Error in request. Possibly authentication failed [500]: Server Error

2021-02-17T17:30:00.004+05:30

Full Error.

Traceback (most recent call last):

  File "/root/scripts/jenkins_jobs_scrape.py", line 159, in <module>
    jobNames = process_view_config(workspace_root, job_list)
  File "/root/scripts/jenkins_jobs_scrape.py", line 120, in process_view_config
    config = ET.fromstring(server.get_job_config(job_name))
  File "/usr/lib/python2.7/site-packages/jenkins/__init__.py", line 1006, in get_job_config
    return self.jenkins_open(request)
  File "/usr/lib/python2.7/site-packages/jenkins/__init__.py", line 448, in jenkins_open
    e.code, e.msg)
jenkins.JenkinsException: Error in request. Possibly authentication failed [500]: Server Error

 In this python script i login on jenkins & pull data.

So fix for me - my 2 jenkins jobs - have illegal parameter, i disable the same & work fine for me.

Possible cause of error: so follow the same.

Permission problem, the current user does not have operation permissions
User verification error, such as token verification failure
Illegal parameter passed in
The config_xml specified by create_job must be utf-8 encoding

Creating and accepting a VPC peering connection || AWS Hindi Video

2020-12-29T15:31:00.001+05:30

aws vpc peering

What is VPC peering? A VPC peering connection is a networking connection between two VPCs that enables you to route traffic between them using private IPv4 addresses or IPv6 addresses. Instances in either VPC can communicate with each other as if they are within the same network. You can create a VPC peering connection between your own VPCs, or with a VPC in another AWS account. The VPCs can be in different regions (also known as an inter-region VPC peering connection). Important Ensure that your VPCs do not have overlapping IPv4 CIDR blocks. If they do, the status of the VPC peering connection immediately goes to failed. This limitation applies even if the VPCs have unique IPv6 CIDR blocks.

How To Install PostgreSQL 12 on RHEL 7 (Red Hat)

2020-12-01T12:28:00.003+05:30

PostgreSQL - Install Specific Version of a Package

In my example i need to install PostgreSQL 12.2

OS Details = $ cat /etc/redhat-release

Red Hat Enterprise Linux Server release 7.8 (Maipo)

Run command to install PostgreSQL 12

# yum install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm

# yum install postgresql12-12.2-2* postgresql12-contrib-12.2-2* postgresql12-server-12.2-2*

Note - if you want to install latest version for PostgreSQL 12 - just run command like below.

#yum install postgresql12-server postgresql12-contrib postgresql12-libs postgresql12

--> Finished Dependency Resolution

Dependencies Resolved

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

Package Arch Version Repository Size

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

Installing:

postgresql12 x86_64 12.2-2PGDG.rhel7 pgdg12 1.6 M

postgresql12-contrib x86_64 12.2-2PGDG.rhel7 pgdg12 608 k

postgresql12-server x86_64 12.2-2PGDG.rhel7 pgdg12 4.9 M

Installing for dependencies:

postgresql12-libs x86_64 12.2-2PGDG.rhel7 pgdg12 367 k

Transaction Summary

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

Install 3 Packages (+1 Dependent package)

Total download size: 7.4 M

Installed size: 31 M

Is this ok [y/d/N]: y

Downloading packages:

(1/4): postgresql12-contrib-12.2-2PGDG.rhel7.x86_64.rpm | 608 kB 00:00:05

(2/4): postgresql12-libs-12.2-2PGDG.rhel7.x86_64.rpm | 367 kB 00:00:01

(3/4): postgresql12-12.2-2PGDG.rhel7.x86_64.rpm | 1.6 MB 00:00:06

(4/4): postgresql12-server-12.2-2PGDG.rhel7.x86_64.rpm | 4.9 MB 00:00:06

-----------------------------------------------------------------------------------------------------------------------------------------------

Total 575 kB/s | 7.4 MB 00:00:13

Running transaction check

Running transaction test

Transaction test succeeded

Running transaction

Installing : postgresql12-libs-12.2-2PGDG.rhel7.x86_64 1/4

Installing : postgresql12-12.2-2PGDG.rhel7.x86_64 2/4

Installing : postgresql12-contrib-12.2-2PGDG.rhel7.x86_64 3/4

Installing : postgresql12-server-12.2-2PGDG.rhel7.x86_64 4/4

Verifying : postgresql12-contrib-12.2-2PGDG.rhel7.x86_64 1/4

Verifying : postgresql12-12.2-2PGDG.rhel7.x86_64 2/4

Verifying : postgresql12-server-12.2-2PGDG.rhel7.x86_64 3/4

Verifying : postgresql12-libs-12.2-2PGDG.rhel7.x86_64 4/4

Installed:

postgresql12.x86_64 0:12.2-2PGDG.rhel7 postgresql12-contrib.x86_64 0:12.2-2PGDG.rhel7 postgresql12-server.x86_64 0:12.2-2PGDG.rhel7

Dependency Installed:

postgresql12-libs.x86_64 0:12.2-2PGDG.rhel7

Complete!

# Optionally initialize the database and enable automatic start:

# /usr/pgsql-12/bin/postgresql-12-setup initdb

Initializing database ... OK

#systemctl enable postgresql-12

#sudo systemctl start postgresql-12

# systemctl status postgresql-12

● postgresql-12.service - PostgreSQL 12 database server

Loaded: loaded (/usr/lib/systemd/system/postgresql-12.service; enabled; vendor preset: disabled)

Active: active (running) since Tue 2020-12-01 06:34:45 UTC; 42s ago

Docs: https://www.postgresql.org/docs/12/static/

Process: 984 ExecStartPre=/usr/pgsql-12/bin/postgresql-12-check-db-dir ${PGDATA} (code=exited, status=0/SUCCESS)

Main PID: 1012 (postmaster)

CGroup: /system.slice/postgresql-12.service

├─1012 /usr/pgsql-12/bin/postmaster -D /var/lib/pgsql/12/data/

├─1078 postgres: logger

├─1096 postgres: checkpointer

├─1097 postgres: background writer

├─1098 postgres: walwriter

URL For Ref = https://download.postgresql.org/pub/repos/yum/12/redhat/rhel-7-x86_64/

https://www.postgresql.org/download/linux/redhat/

How to remove multiple rpm packages with the same name?

2020-10-30T14:04:00.004+05:30

How to remove multiple rpm packages with the same name?

FIX

[root@raman ~]# rpm -e --allmatches packagename

To force remove the package

[root@raman ~]#rpm -e --allmatches --nodeps [packagename]

How To Solve “Error: rpmdb open failed” Error In RedHat

2020-10-09T18:11:00.001+05:30

Recurring corruption of rpmdb on RHEL 7

# yum install telnet

error: rpmdb: BDB0113 Thread/process 4120/139972365821760 failed: BDB1507 Thread died in Berkeley DB library

error: db5 error(-30973) from dbenv->failchk: BDB0087 DB_RUNRECOVERY: Fatal error, run database recovery

error: cannot open Packages index using db5 - (-30973)

error: cannot open Packages database in /var/lib/rpm

CRITICAL:yum.main:

Solution:-

Error: rpmdb open failed

# mv /var/lib/rpm/__db* /tmp

# yum clean all

# yum install telnet

Verifying : 1:telnet-0.17-64.el7.x86_64 2/2

Updated:

telnet.x86_64 1:0.17-65.el7_8

Complete!

Fixed - Bad magic number in super-block - Attempting to extend filesystem

2020-10-07T17:51:00.005+05:30

[root@redhat-8]# pvcreate /dev/sdb1

Physical volume "/dev/sdb1" successfully created.

[root@redhat-8]# vgdisplay

--- Volume group ---

VG Name rhel

System ID

Format lvm2

[root@redhat-8]# vgextend rhel /dev/sdb1

Volume group "rhel" successfully extended

[root@redhat-8]# lvextend -L+15G /dev/mapper/rhel-root

Size of logical volume rhel/root changed from 36.32 GiB (9298 extents) to 51.32 GiB (13138 extents).

Logical volume rhel/root successfully resized.

[root@redhat-8]# resize2fs /dev/mapper/rhel-root

resize2fs 1.44.3 (10-July-2018)

resize2fs: Bad magic number in super-block while trying to open /dev/mapper/rhel-root

Couldn't find valid filesystem superblock.

[root@redhat-8]# mount | grep rhel-root

/dev/mapper/rhel-root on / type xfs (rw,relatime,attr2,inode64,noquota)

[root@redhat-8]# partprobe -s

/dev/sda: msdos partitions 1 2

/dev/sdb: msdos partitions 1

[root@redhat-8]# lsblk

NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT

sda 8:0 0 60G 0 disk

├─sda1 8:1 0 1G 0 part /boot

└─sda2 8:2 0 59G 0 part

├─rhel-root 253:0 0 51.3G 0 lvm /

├─rhel-swap 253:1 0 5G 0 lvm [SWAP]

└─rhel-home 253:2 0 17.8G 0 lvm /home

sdb 8:16 0 52G 0 disk

└─sdb1 8:17 0 52G 0 part

└─rhel-root 253:0 0 51.3G 0 lvm /

NOT WORK FOR ME.

(resize2fs command work with EXT filesystem)

e.g

# mount | grep /dev/mapper/vg_root-lv_root

/dev/mapper/vg_root-lv_root on / type ext4 (rw,relatime,data=ordered)

In Red Hat Enterprise Linux 7, the default filesystem type is XFS which uses the xfs_growfs command instead.

[root@redhat-8]# xfs_growfs /dev/mapper/rhel-root

xfs_growfs: /dev/mapper/rhel-root is not a mounted XFS filesystem

Further Digging

[root@redhat-8 ~]# df -Th

Filesystem Type Size Used Avail Use% Mounted on

/dev/mapper/rhel-root xfs 37G 34G 2.4G 94% /

/dev/mapper/rhel-home xfs 18G 12G 6.2G 66% /home

/dev/sda1 xfs 1014M 169M 846M 17% /boot

Final Fix - MY-Redhat-Bugzilla

[root@redhat-8 ~]# pvscan

PV /dev/sda2 VG rhel lvm2 [<59.00 GiB / 0 free]

PV /dev/sdb1 VG rhel lvm2 [<52.00 GiB / <37.00 GiB free]

Total: 2 [110.99 GiB] / in use: 2 [110.99 GiB] / in no VG: 0 [0 ]

[root@redhat-8 ~]# df -h

Filesystem Size Used Avail Use% Mounted on

devtmpfs 7.8G 0 7.8G 0% /dev

tmpfs 7.8G 0 7.8G 0% /dev/shm

tmpfs 7.8G 9.3M 7.8G 1% /run

tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup

/dev/mapper/rhel-root 37G 34G 2.4G 94% /

/dev/mapper/rhel-home 18G 13G 5.6G 69% /home

[root@redhat-8 ~]# lvextend -r -L+5G /dev/mapper/rhel-root

Size of logical volume rhel/root changed from 51.32 GiB (13138 extents) to 56.32 GiB (14418 extents).

Logical volume rhel/root successfully resized.

meta-data=/dev/mapper/rhel-root isize=512 agcount=4, agsize=2380288 blks

= sectsz=512 attr=2, projid32bit=1

= crc=1 finobt=1, sparse=1, rmapbt=0

= reflink=1

data = bsize=4096 blocks=9521152, imaxpct=25

= sunit=0 swidth=0 blks

naming =version 2 bsize=4096 ascii-ci=0, ftype=1

log =internal log bsize=4096 blocks=4649, version=2

= sectsz=512 sunit=0 blks, lazy-count=1

realtime =none extsz=4096 blocks=0, rtextents=0

data blocks changed from 9521152 to 14764032

[root@redhat-8 ~]# df -h

Filesystem Size Used Avail Use% Mounted on

devtmpfs 7.8G 0 7.8G 0% /dev

tmpfs 7.8G 0 7.8G 0% /dev/shm

tmpfs 7.8G 9.3M 7.8G 1% /run

tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup

/dev/mapper/rhel-root 57G 35G 23G 61% /

/dev/mapper/rhel-home 18G 13G 5.6G 69% /home

How to Create, Mount XFS Filesystem on RHEL 7

2020-10-05T13:00:00.004+05:30

How to Create, Mount and Extend xfs Filesystem

Straight forward Steps.

Creating a new XFS partition

1)Added 25GB HDD

Disk /dev/sdb: 26.8 GB, 26843545600 bytes, 52428800 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

2) Format disk.

# fdisk /dev/sdb

Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.

Be careful before using the write command.

Device does not contain a recognized partition table

Building a new DOS disklabel with disk identifier 0x5c7cc34a.

Command (m for help): n

Partition type:

p primary (0 primary, 0 extended, 4 free)

e extended

Select (default p): p

Partition number (1-4, default 1):

First sector (2048-52428799, default 2048):

Using default value 2048

Last sector, +sectors or +size{K,M,G} (2048-52428799, default 52428799):

Using default value 52428799

Partition 1 of type Linux and of size 25 GiB is set

Command (m for help): w

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

Now you have.

Device Boot Start End Blocks Id System

/dev/sdb1 2048 52428799 26213376 83 Linux

3)Format with XFS

Now that your partition is ready you can create a xfs filesystem by using the mkfs.xfs command, with the name of the partition you created like this-

# mkfs.xfs /dev/sdb1

meta-data=/dev/sdb1 isize=512 agcount=4, agsize=1638336 blks

= sectsz=512 attr=2, projid32bit=1

= crc=1 finobt=0, sparse=0

data = bsize=4096 blocks=6553344, imaxpct=25

= sunit=0 swidth=0 blks

naming =version 2 bsize=4096 ascii-ci=0 ftype=1

log =internal log bsize=4096 blocks=3199, version=2

= sectsz=512 sunit=0 blks, lazy-count=1

realtime =none extsz=4096 blocks=0, rtextents=0

4) Mounting the xfs filesystem

# mkdir /app1

# mount /dev/sdb1 /app1/

5) Verify

#df -h

/dev/sdb1 25G 33M 25G 1% /app1

# mount | grep /dev/sdb1

/dev/sdb1 on /app1 type xfs (rw,relatime,seclabel,attr2,inode64,noquota)

Nginx - Redirects with Nginx - Different URL / Remote Web Server.

2020-09-07T16:02:00.002+05:30

Nginx - Redirects with Nginx - Different URL / Remote Web Server.

Setup Nginx Server in Front of my http Web server (apache/httpd)

Two URL i need to redirect from Nginx to Httpd.

Two Simple nginx Page setup - here below the screen shot for both.

Solution --

In Nginx, you can accomplish most redirects with the built-in rewrite directive. This directive is available by default on a fresh Nginx installation and can be used to create both temporary and permanent redirects.

Now for redirect - i create conf file under /etc/nginx/conf.d/ - configuration attached as screen shot.

Save the setting. Restart NGINX must.

Now when i hit the two above mentioned URL - i redirect like above screenshot.

Further updated conf - all working - URL - with diff purpose.

P.S = Keep IT Simple.

How to import SSL certificates into keystore? Linux

2020-07-23T15:25:00.001+05:30

In my case i got SSL certificate i.e test.cer, now my task to import this certificate in my RHEL 7 machine.

This can be achieve via keytool command.

[root@raman tmp]# keytool -import -v -trustcacerts -alias test -file test.cer -keystore test-truststore.ts

Enter keystore password:

Re-enter new password:

Owner: CN=test.****.****i.com, OU=test, O=test, L=Miami, ST=FL, C=US

Issuer: CN=test.****.****i.com, OU=test, O=test, L=Miami, ST=FL, C=US

Serial number: d4386496aa5d74d53a6d19513e35334972

Valid from: Wed Mar 11 02:13:03 AEDT 2020 until: Thu Mar 11 02:13:03 AEDT 2021

Certificate fingerprints:

MD5: C9:9A:17:9F:1E:53:8A:28:94:B8:90:06:5F:24:00

SHA1: 75:7A:CE:93:A4:A4:91:2D:62:59:E0:FB:AA:B6:C0:D1:E8:56:71

SHA256: 5F:3C:AD:FC:D4:3C:F6:2E:CD:09:D3:A0:87:F7:09:C7:99:AE:8D:A3:39:01:BB:58:64:D7:09:9E:94:AF:5F

Signature algorithm name: SHA512withRSA

Version: 3

Trust this certificate? [no]: yes

Certificate was added to keystore

[Storing test-truststore.ts]

Validate / check the contents of your keystore using the command as following.

[root@raman tmp]# keytool -list -v -keystore test-truststore.ts

Enter keystore password:

Keystore type: JKS

Keystore provider: SUN

Your keystore contains 1 entry

Alias name: test

Creation date: 20/07/2020

Entry type: trustedCertEntry

Owner: CN=test.****.****i.com, OU=test, O=test, L=Miami, ST=FL, C=US

Issuer: CN=test.****.****i.com, OU=test, O=test, L=Miami, ST=FL, C=US

Serial number: d4386496aa5d74d53a6d19513e35334972

Valid from: Wed Mar 11 02:13:03 AEDT 2020 until: Thu Mar 11 02:13:03 AEDT 2021

Certificate fingerprints:

MD5: C9:9A:17:9F:1E:53:8A:28:94:B8:90:06:5F:24:00

SHA1: 75:7A:CE:93:A4:A4:91:2D:62:59:E0:FB:AA:B6:C0:D1:E8:56:71

SHA256: 5F:3C:AD:FC:D4:3C:F6:2E:CD:09:D3:A0:87:F7:09:C7:99:AE:8D:A3:39:01:BB:58:64:D7:09:9E:94:AF:5F

Signature algorithm name: SHA512withRSA

Version: 3

*******************************************

Fix - Could not find goal 'native2ascii' in plugin org.codehaus.mojo:native2ascii-maven-plugin:2.0.1

2020-07-22T16:43:00.000+05:30

In Jenkins i encounter with following error.

Join notifier requires a CauseAction
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.733s
[INFO] Finished at: Wed Jul 22 08:07:39 UTC 2020
[INFO] Final Memory: 12M/981M
[INFO] ------------------------------------------------------------------------
Waiting for Jenkins to finish collecting data
[ERROR] Could not find goal 'native2ascii' in plugin org.codehaus.mojo:native2ascii-maven-plugin:2.0.1 among available goals help, inplace, resources, testResources -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoNotFoundException

My POM.XML

Fix - Work for Me.

Modify 3 line in POM.XML

<workDir>src/main/resources/content</workDir>
<tempDir>target/classes/content</tempDir>
<goal>resources</goal>

How to convert SSL/TLS certificate from .crt to .pem format ? Redhat - CentOS

2020-07-20T12:22:00.000+05:30

How to convert SSL/TLS certificate from .crt to .pem format ?

Run following 2 command to Covert.

#openssl x509 -in myweb.crt -out myweb.der -outform DER (first convert the CRT file to a DER file)

#openssl x509 -in myweb.der -inform DER -out myweb.pem -outform PEM (convert the .der file to a PEM file)

Install Chrome on Linux - Fix Google Chrome Dependencies

2020-06-25T16:33:00.000+05:30

Download RPM from - https://www.google.com/chrome/browser/desktop/index.html

-rw-rw-r--. 1 savita savita 68470916 Jun 20 16:24 google-chrome-stable_current_x86_64.rpm

[savita@localhost Downloads]$ sudo rpm -ivh google-chrome-stable_current_x86_64.rpm

[sudo] password for savita:
warning: google-chrome-stable_current_x86_64.rpm: Header V4 DSA/SHA1 Signature, key ID 7fac5991: NOKEY
error: Failed dependencies:
    libXss.so.1()(64bit) is needed by google-chrome-stable-83.0.4103.106-1.x86_64
    libappindicator3.so.1()(64bit) is needed by google-chrome-stable-83.0.4103.106-1.x86_64
    liberation-fonts is needed by google-chrome-stable-83.0.4103.106-1.x86_64
    libvulkan.so.1()(64bit) is needed by google-chrome-stable-83.0.4103.106-1.x86_64

Fix -

[root@localhost ~]# dnf install fedora-workstation-repositories

[root@localhost ~]# dnf config-manager --set-enabled google-chrome

[root@localhost ~]# dnf install google-chrome-stable -y

Installed:
google-chrome-stable.x86_64 83.0.4103.106-1      libXScrnSaver.x86_64 1.2.2-14.fc28            libappindicator-gtk3.x86_64 12.10.0-16.fc27          libdbusmenu.x86_64 16.04.0-5.fc28
libdbusmenu-gtk3.x86_64 16.04.0-5.fc28           liberation-fonts.noarch 1:1.07.4-11.fc28      liberation-narrow-fonts.noarch 1:1.07.4-11.fc28      libindicator-gtk3.x86_64 12.10.1-12.fc28
mesa-vulkan-drivers.x86_64 18.0.5-4.fc28         vulkan-loader.x86_64 1.1.77.0-4.fc28

Complete!

Fixed - RTL8723DE Wireless with Kernel 5.0.16-100

2020-06-23T16:21:00.000+05:30

$ lspci
02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723DE 802.11b/g/n PCIe Adapter

kernel -- 5.0.16-100.fc28.x86_64

[savita@localhost tmp]$ git clone https://github.com/smlinux/rtl8723de.git -b 5.0-up

Cloning into 'rtl8723de'...
remote: Enumerating objects: 38, done.
remote: Counting objects: 100% (38/38), done.
remote: Compressing objects: 100% (33/33), done.
remote: Total 639 (delta 15), reused 15 (delta 5), pack-reused 601
Receiving objects: 100% (639/639), 2.72 MiB | 1.51 MiB/s, done.
Resolving deltas: 100% (230/230), done.
[savita@localhost tmp]$ sudo dkms add ./rtl8723de

Creating symlink /var/lib/dkms/rtl8723de/5.1.1.8_21285.20171026_COEX20170111-1414/source ->
                 /usr/src/rtl8723de-5.1.1.8_21285.20171026_COEX20170111-1414

DKMS: add completed.
[savita@localhost tmp]$ sudo dkms install rtl8723de/5.1.1.8_21285.20171026_COEX20170111-1414

Kernel preparation unnecessary for this kernel. Skipping...

Building module:
cleaning build area...
'make' all KVER=5.0.16-100.fc28.x86_64........................
cleaning build area...

DKMS: build completed.

rtl8723de.ko.xz:
Running module version sanity check.
- Original module
   - No original module exists within this kernel
- Installation
   - Installing to /lib/modules/5.0.16-100.fc28.x86_64/extra/
Adding any weak-modules

depmod....

DKMS: install completed.

Now i can see wifi adapter and network. In my case reboot not required.

Cheers..enjoy.

P.S = Keep IT Simple.

how change shell in Linux - Unix

2020-06-19T16:21:00.001+05:30

Linux / UNIX: Change Bash To KSH Shell

Current Shell

[myid@tmp rpm]$ grep "^adm" /etc/passwd

adm:x:1000:1000:Admin:/home/adm:/bin/bash

# chsh -s /bin/ksh adm

Changing shell for adm.

chsh: "/bin/ksh" does not exist

Install the package of ksh shell:

#yum install ksh

Installed:

ksh.x86_64 0:20120801-140.el7_7

Complete!

# cat /etc/shells

/bin/sh

/bin/bash

/sbin/nologin

/usr/bin/sh

/usr/bin/bash

/usr/sbin/nologin

/bin/ksh

/bin/rksh

# chsh -s /bin/ksh adm

Changing shell for adm.

Shell changed.

Verify after login with adm user as well.

$ echo $0

-ksh

subscription-manager list command fails with ERROR - Network error code: 400 - FIXED

2020-06-16T19:02:00.001+05:30

subscription-manager list command fails with ERROR - Network error code: 400

Network error, unable to connect to server" when registering RHEL server using subscription-manager || Why does yum fail with error "[Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 403" ?

# subscription-manager list --available --all | more

Error updating system data on the server, see /var/log/rhsm/rhsm.log for more details.

Log --- /var/log/rhsm/rhsm.log

raise Exception(_("Error updating system data on the server, see /var/log/rhsm/rhsm.log "

Exception: Error updating system data on the server, see /var/log/rhsm/rhsm.log for more details.

2020-06-16 12:35:22,466 [INFO] subscription-manager:17927:MainThread @cache.py:410 - Server does not support packages, skipping profile upload.

2020-06-16 12:35:24,090 [INFO] subscription-manager:17927:MainThread @connection.py:551 - Response: status=400, request="GET /subscription/consumers/c590d51a-13dc-46a7-83d8-e662fdb3b45e /compliance"

2020-06-16 12:35:24,091 [ERROR] subscription-manager:17927:MainThread @connection.py:576 - Response: 400

2020-06-16 12:35:24,091 [ERROR] subscription-manager:17927:MainThread @connection.py:577 - JSON parsing error: No JSON object could be decoded

2020-06-16 12:35:24,092 [ERROR] subscription-manager:17927:MainThread @cache.py:235 - Network error code: 400

2020-06-16 12:35:24,092 [WARNING] subscription-manager:17927:MainThread @cache.py:241 - Unable to reach server, using cached status.

2020-06-16 12:35:24,094 [INFO] subscription-manager:17927:MainThread @cert_sorter.py:204 - Product status: valid_products=69 partial_products= expired_products= unentitled_producs= futu re_products= valid_until=2020-02-14 00:00:00+00:00

2020-06-16 12:35:37,937 [INFO] subscription-manager:17927:MainThread @connection.py:821 - Connection built: http_proxy=myproxy.rk.com:8080 host=subscription.rhsm.redhat.com port=44 3 handler=/subscription auth=identity_cert ca_dir=/etc/rhsm/ca/ insecure=False

2020-06-16 12:35:39,638 [INFO] subscription-manager:17927:MainThread @connection.py:551 - Response: status=400, request="GET /subscription/"

2020-06-16 12:35:39,639 [ERROR] subscription-manager:17927:MainThread @connection.py:576 - Response: 400

2020-06-16 12:35:39,639 [ERROR] subscription-manager:17927:MainThread @connection.py:577 - JSON parsing error: No JSON object could be decoded

2020-06-16 12:35:39,640 [ERROR] subscription-manager:17927:MainThread @managercli.py:177 - exception caught in subscription-manager

2020-06-16 12:35:39,640 [ERROR] subscription-manager:17927:MainThread @managercli.py:178 - Network error code: 400

Traceback (most recent call last):

File "/usr/sbin/subscription-manager", line 94, in <module>

sys.exit(abs(main() or 0))

File "/usr/sbin/subscription-manager", line 85, in main

return managercli.ManagerCLI().main()

File "/usr/lib/python2.7/site-packages/subscription_manager/managercli.py", line 2824, in main

return CLI.main(self)

File "/usr/lib/python2.7/site-packages/subscription_manager/cli.py", line 158, in main

return cmd.main()

File "/usr/lib/python2.7/site-packages/subscription_manager/managercli.py", line 562, in main

return_code = self._do_command()

File "/usr/lib/python2.7/site-packages/subscription_manager/managercli.py", line 2117, in _do_command

repos = rl.get_repos()

File "/usr/lib/python2.7/site-packages/subscription_manager/repolib.py", line 84, in get_repos

apply_overrides=apply_overrides)

File "/usr/lib/python2.7/site-packages/subscription_manager/repolib.py", line 233, in __init__

self.override_supported = bool(self.identity.is_valid() and self.uep and self.uep.supports_resource('content_overrides'))

File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 847, in supports_resource

self._load_supported_resources()

File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 834, in _load_supported_resources

resources_list = self.conn.request_get("/")

File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 645, in request_get

return self._request("GET", method, headers=headers)

File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 671, in _request

info=info, headers=headers)

File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 560, in _request

self.validateResponse(result, request_type, handler)

File "/usr/lib64/python2.7/site-packages/rhsm/connection.py", line 632, in validateResponse

raise NetworkException(response['status'])

NetworkException: Network error code: 400

FIX---

Check that the subscription host can be resolved:(advise you to use DNS and not hard code the IP address of the subscription host)

#host $( grep ^hostname /etc/rhsm/rhsm.conf | cut -d '=' -f 2 )

subscription.rhsm.redhat.com has address 209.132.183.107

# subscription-manager list

+-------------------------------------------+

Installed Product Status

+-------------------------------------------+

Product Name: Red Hat Enterprise Linux Server

Product ID: 69

Version: 7.4

Arch: x86_64

Status: Subscribed

Status Details:

Starts:

Ends:

[root@rhel7-pc daily]# subscription-manager clean

All local data removed

[root@rhel7-pc daily]# subscription-manager attach --auto

This system is not yet registered. Try 'subscription-manager register --help' for more information.

[root@rhel7-pc daily]# subscription-manager register --username redhat-rk --password trynewpassword

Registering to: subscription.rhsm.redhat.com:443/subscription

The system has been registered with ID: 643736e9-154b-1326-8wf7-83c3d3b32658e

[root@rhel7-pc daily]# subscription-manager status

+-------------------------------------------+

System Status Details

+-------------------------------------------+

Overall Status: Invalid

Red Hat Enterprise Linux Server:

- Not supported by a valid subscription.

[root@rhel7-pc daily]# subscription-manager attach --auto

Installed Product Current Status:

Product Name: Red Hat Enterprise Linux Server

Status: Subscribed

# subscription-manager status

+-------------------------------------------+

System Status Details

+-------------------------------------------+

Overall Status: Current

# subscription-manager list --available --all | more

+-------------------------------------------+

Available Subscriptions

+-------------------------------------------+

Subscription Name: Red Hat OpenShift Broker/Master Infrastructure (2 Cores)

Provides: dotNET on RHEL Beta (for RHEL Server)

Oracle Java (for RHEL Server)

Red Hat Software Collections (for RHEL Server)

Red Hat CodeReady Linux Builder for x86_64

Red Hat Ansible Engine

Red Hat OpenShift Enterprise Infrastructure

Red Hat Enterprise Linux Fast Datapath

Red Hat CloudForms

Red Hat Enterprise Linux Atomic Host

Red Hat Enterprise Linux Fast Datapath Beta for x86_64

Red Hat Beta

Red Hat Software Collections Beta (for RHEL Server)

Red Hat Enterprise Linux Server

Red Hat Enterprise Linux for x86_64

Red Hat Enterprise Linux for x86_64 - Extended Update Support

Red Hat OpenShift Container Platform

Red Hat OpenShift Service Mesh

Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support

dotNET on RHEL (for RHEL Server)

Red Hat OpenShift Enterprise Client Tools

Red Hat CloudForms Beta

SKU: MCT2741

Contract:

Pool ID: 8a85f99c727513fe017275ca469c3237

Provides Management: Yes

Available: Unlimited

Suggested: 1

Service Level: Layered

Service Type: L1-L3

Subscription Type: Stackable

Ends: 01/08/20

System Type: Virtual

Subscription Name: Red Hat OpenShift Broker/Master Infrastructure (2 Cores)

Provides: dotNET on RHEL Beta (for RHEL Server)

So ON .... Work fine.

PS = Keep IT Simple

Install Google Chrome on Fedora 32

2020-06-10T15:57:00.000+05:30

Do login as Root

[savita@savita rtlwifi_new]$ su -
Password:
[root@savita ~]# dnf install fedora-workstation-repositories
RPM Fusion for Fedora 32 - Free - Updates                                                                                                  346 kB/s | 506 kB     00:01
RPM Fusion for Fedora 32 - Free                                                                                                            606 kB/s | 679 kB     00:01
RPM Fusion for Fedora 32 - Nonfree - Updates                                                                                               9.0 kB/s | 45 kB     00:04
RPM Fusion for Fedora 32 - Nonfree                                                                                                          80 kB/s | 225 kB     00:02
Dependencies resolved.
===========================================================================================================================================================================
Package                                                   Architecture                     Version                                Repository                         Size
===========================================================================================================================================================================
Installing:
fedora-workstation-repositories                           noarch                           32-3.fc32                              fedora                            9.2 k
Installing dependencies:
distribution-gpg-keys                                     noarch                           1.39-1.fc32                            updates                           239 k

Transaction Summary
===========================================================================================================================================================================
Install 2 Packages

Total download size: 248 k
Installed size: 328 k
Is this ok [y/N]: y
Downloading Packages:
(1/2): fedora-workstation-repositories-32-3.fc32.noarch.rpm                                                                                 20 kB/s | 9.2 kB     00:00
(2/2): distribution-gpg-keys-1.39-1.fc32.noarch.rpm                                                                                                                                                            92 kB/s | 239 kB     00:02
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total                                                                                                                                                                                                          54 kB/s | 248 kB     00:04
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing        :                                                                                                                                                                                                                      1/1
Installing       : distribution-gpg-keys-1.39-1.fc32.noarch                                                                                                                                                                             1/2
Installing       : fedora-workstation-repositories-32-3.fc32.noarch                                                                                                                                                                     2/2
Verifying        : distribution-gpg-keys-1.39-1.fc32.noarch                                                                                                                                                                             1/2
Verifying        : fedora-workstation-repositories-32-3.fc32.noarch                                                                                                                                                                     2/2

Installed:
distribution-gpg-keys-1.39-1.fc32.noarch                                                                          fedora-workstation-repositories-32-3.fc32.noarch

Complete!

root@savita ~]# dnf config-manager --set-enabled google-chrome

[root@savita ~]# dnf install google-chrome-stable -y
Last metadata expiration check: 0:00:11 ago on Tue 09 Jun 2020 03:54:45 PM IST.
Dependencies resolved.
==============================================================================================================================================================================================================================================
Package                                                         Architecture                                      Version                                                     Repository                                                Size
==============================================================================================================================================================================================================================================
Installing:
google-chrome-stable                                            x86_64                                            83.0.4103.97-1                                              google-chrome                                             65 M
Installing dependencies:
libappindicator-gtk3                                            x86_64                                            12.10.0-28.fc32                                             updates                                                   42 k
libdbusmenu                                                     x86_64                                            16.04.0-15.fc32                                             fedora                                                   136 k
libdbusmenu-gtk3                                                x86_64                                            16.04.0-15.fc32                                             fedora                                                    41 k
liberation-fonts                                                noarch                                            1:2.1.0-1.fc32                                              fedora                                                   8.3 k
libindicator-gtk3                                               x86_64                                            12.10.1-17.fc32                                             fedora                                                    67 k

Transaction Summary
==============================================================================================================================================================================================================================================
Install 6 Packages

Installed:
google-chrome-stable-83.0.4103.97-1.x86_64        libappindicator-gtk3-12.10.0-28.fc32.x86_64        libdbusmenu-16.04.0-15.fc32.x86_64        libdbusmenu-gtk3-16.04.0-15.fc32.x86_64        liberation-fonts-1:2.1.0-1.fc32.noarch
libindicator-gtk3-12.10.1-17.fc32.x86_64

Complete!

install - RPM Fusion - Fedora 32

2020-06-09T15:50:00.001+05:30

Installing Free and Nonfree Repositories

RPMFUSION - Fedroa 32

savita@savita rtlwifi_new]$ cat /etc/redhat-release
Fedora release 32 (Thirty Two)

[savita@savita rtlwifi_new]$ uname -a

Linux savita 5.6.16-300.fc32.x86_64 #1 SMP Thu Jun 4 18:08:38 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

Command Line Setup using rpm

[savita@savita rtlwifi_new]$ sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm
[sudo] password for savita:
Last metadata expiration check: 2:56:58 ago on Tue 09 Jun 2020 12:49:41 PM IST.
rpmfusion-free-release-32.noarch.rpm                                                                                                        23 kB/s | 13 kB     00:00
rpmfusion-nonfree-release-32.noarch.rpm                                                                                                     23 kB/s | 13 kB     00:00
Dependencies resolved.
===========================================================================================================================================================================
Package                                               Architecture                       Version                           Repository                                Size
===========================================================================================================================================================================
Installing:
rpmfusion-free-release                                noarch                             32-1                              @commandline                              13 k
rpmfusion-nonfree-release                             noarch                             32-1                              @commandline                              13 k

Transaction Summary
===========================================================================================================================================================================
Install 2 Packages

Total size: 25 k
Installed size: 14 k
Is this ok [y/N]: y
Downloading Packages:
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing        :                                                                                                                                                   1/1
Installing       : rpmfusion-nonfree-release-32-1.noarch                                                                                                             1/2
Installing       : rpmfusion-free-release-32-1.noarch                                                                                                                2/2
Verifying        : rpmfusion-free-release-32-1.noarch                                                                                                                1/2
Verifying        : rpmfusion-nonfree-release-32-1.noarch                                                                                                             2/2

Installed:
rpmfusion-free-release-32-1.noarch                                                 rpmfusion-nonfree-release-32-1.noarch

Complete!

Installing OpenJDK 8 on RHEL-based Systems

2020-05-08T13:04:00.001+05:30

INSTALLING JAVA ON RHEL 8

# cat /etc/redhat-release

Red Hat Enterprise Linux release 8.0 (Ootpa)

Download the latest version of the JRE ZIP bundle for Linux.

Download the required -- java-1.8.0-openjdk-1.8.0.242.b08-1.static.jre.openjdkportable.x86_64.tar.xz

Switch directory where i need to install.

#cd /usr/lib/jvm

extract bundle.

# tar -xf java-1.8.0-openjdk-1.8.0.242.b08-1.static.jre.openjdkportable.x86_64.tar.xz

Create symbolic links (shorter path/generic path)

# ln -s /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.242.b08-1.static.jre.openjdkportable.x86_64 /usr/lib/jvm/java-8-242

Now make it permanent .

# vim /root/.bash_profile

## openjdk

export JAVA_HOME=/usr/lib/jvm/java-8-242

export PATH="$JAVA_HOME/bin:$PATH"

Save – open new session.

# java -version

openjdk version "1.8.0_242"

OpenJDK Runtime Environment (build 1.8.0_242-b08)

OpenJDK 64-Bit Server VM (build 25.242-b08, mixed mode)

hshar/mysql:5.5 - mysql password

2020-04-20T15:45:00.004+05:30

hshar/mysql:5.5

# kubectl exec -it mysqldb-7c79c9dd7d-4tk7v bash ( with this commnad i connect to mysql POD)

root@mysqldb-7c79c9dd7d-4tk7v:/# /usr/local/mysql/bin/mysqladmin -u root password 'utiba'
/usr/local/mysql/bin/mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: NO)'
root@mysqldb-7c79c9dd7d-4tk7v:/# /usr/local/mysql/bin/mysql_secure_installation

NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MySQL
SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!

In order to log into MySQL to secure it, we'll need the current
password for the root user. If you've just installed MySQL, and
you haven't set the root password yet, the password will be blank,
so you should just press enter here.

Enter current password for root (enter for none):
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
Enter current password for root (enter for none):
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
Enter current password for root (enter for none):
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
Enter current password for root (enter for none):
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
Enter current password for root (enter for none):
OK, successfully used password, moving on... (password work for me -- edureka)

Setting the root password ensures that nobody can log into the MySQL
root user without the proper authorisation.

You already have a root password set, so you can safely answer 'n'.

Change the root password? [Y/n] y
New password:
Re-enter new password:
Password updated successfully!
Reloading privilege tables..
... Success!

By default, a MySQL installation has an anonymous user, allowing anyone
to log into MySQL without having to have a user account created for
them. This is intended only for testing, and to make the installation
go a bit smoother. You should remove them before moving into a
production environment.

Remove anonymous users? [Y/n] n
... skipping.

Normally, root should only be allowed to connect from 'localhost'. This
ensures that someone cannot guess at the root password from the network.

Disallow root login remotely? [Y/n] n
... skipping.

By default, MySQL comes with a database named 'test' that anyone can
access. This is also intended only for testing, and should be removed
before moving into a production environment.

Remove test database and access to it? [Y/n] y
- Dropping test database...
ERROR 1008 (HY000) at line 1: Can't drop database 'test'; database doesn't exist
... Failed! Not critical, keep moving...
- Removing privileges on test database...
... Success!

Reloading the privilege tables will ensure that all changes made so far
will take effect immediately.

Reload privilege tables now? [Y/n] y
... Success!

Cleaning up...

All done! If you've completed all of the above steps, your MySQL
installation should now be secure.

Thanks for using MySQL!

root@mysqldb-7c79c9dd7d-4tk7v:/# mysql -u root -p*****
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 27
Server version: 5.5.60 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> exit
Bye

how to install PostgreSQL 10 on RHEL 7.

2020-04-08T12:22:00.001+05:30

Red Hat family

Red Hat Enterprise Linux
CentOS
Fedora
Scientific Linux
Oracle Linux

MY OS version -- Red Hat Enterprise Linux Server release 7.6 (Maipo)

postgres 10 - Installation - QUICK Steps

#yum install https://download.postgresql.org/pub/repos/yum/reporpms/EL-7-x86_64/pgdg-redhat-repo-latest.noarch.rpm

#yum install postgresql10 postgresql10-server postgresql10-contrib postgresql10-libs -y

#/usr/pgsql-10/bin/postgresql-10-setup initdb

# systemctl enable postgresql-10.service

#vim /var/lib/pgsql/10/data/pg_hba.conf

# "local" is for Unix domain socket connections only
local all all trust
host all all 127.0.0.1/32 md5
host all all ::1/128 md5
host all all 0.0.0.0/0 md5

#vim /var/lib/pgsql/10/data/postgresql.conf
listen_addresses = '*'

Start Service.

# systemctl start postgresql-10.service

Now Set password.

# su - postgres
-bash-4.2$ psql
postgres=# alter user postgres with password 'postgres';
ALTER ROLE

[root@my-pc-1 ~]# psql -U postgres
psql (9.2.24, server 10.12)
WARNING: psql version 9.2, server version 10.0.
Some psql features might not work.
Type "help" for help.

postgres=# SELECT version();
version
----------------------------------------------------------------------------------------------------------
PostgreSQL 10.12 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39), 64-bit
(1 row)

postgres=# \q

For Redhat 8 = Must allow firewall. -- If you have a running Firewall service and remote clients should connect to your database server, allow PostgreSQL service.

[root@rhel-8 ~]# firewall-cmd --add-service=postgresql --permanent

success

[root@rhel-8 ~]# firewall-cmd --reload

success

Solved - NL-00280: error creating log stream - RHEL

2020-03-17T15:16:00.001+05:30

[root@mypc.rhel.com 11.2.0]# lsnrctl start

LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 13-MAR-2020 05:17:28

Copyright (c) 1991, 2011, Oracle. All rights reserved.

Starting /u01/app/oracle/product/11.2.0/xe/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 11.2.0.2.0 - Production
NL-00280: error creating log stream /u01/app/oracle/product/11.2.0/xe/network/log/listener.log
NL-00278: cannot open log file
SNL-00016: snlfohd: error opening file
Linux Error: 13: Permission denied

Listener failed to start. See the error message(s) above...

Fix--

#cd /u01/app/oracle/product/11.2.0/xe/network/log/
#touch listener.log
#chmod 766 listener.log

# lsnrctl start

[root@mypc.rhel.com log]# /etc/init.d/oracle-xe status

LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 13-MAR-2020 05:31:19

Copyright (c) 1991, 2011, Oracle. All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC_FOR_XE)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.2.0 - Production
Start Date 13-MAR-2020 05:30:55
Uptime 0 days 0 hr. 0 min. 23 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Default Service XE
Listener Parameter File /u01/app/oracle/product/11.2.0/xe/network/admin/listener.ora
Listener Log File /u01/app/oracle/product/11.2.0/xe/network/log/listener.log
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC_FOR_XE)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=mypc.rhel.com)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=mypc.rhel.com)(PORT=8080))(Presentation=HTTP)(Session=RAW))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "XE" has 1 instance(s).
Instance "XE", status READY, has 1 handler(s) for this service...
Service "XEXDB" has 1 instance(s).
Instance "XE", status READY, has 1 handler(s) for this service...
The command completed successfully

SSH Tunnel - SSH Port Forwarding Example - Quick Step

2020-03-04T11:11:00.000+05:30

Need to Access URL from AWS box. ( no direct connectivity - 1st i need to jump on bastion/jump box then AWS box) so below steps help me to open URL on local - restricted env.

1st jump box

#ssh -L 12001:localhost:8180 utiba@10.196.228.236

2nd from jump to AWS box

#ssh -L 8180:localhost:8180 -i mykey.pem raman@3.15.**.** (aws box ip)

On your local machine browser -->

http://localhost:12001/portal/server/

Work as expected.

Tomat - Java application OutOfMemoryError PermGen space - Fixed

2020-02-07T14:35:00.002+05:30

Error - when i hit url
HTTP Status 500 – Internal Server Error
Type Exception Report

Message Handler processing failed; nested exception is java.lang.OutOfMemoryError: PermGen space

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.springframework.web.util.NestedServletException: Handler processing failed; nested exception is java.lang.OutOfMemoryError: PermGen space
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:839)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:669)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:574)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
com.jamasoftware.contour.view.filter.CheckSetupFilter.doFilter(CheckSetupFilter.java:60)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:109)
com.jamasoftware.contour.view.filter.ContourConcurrentSessionFilter.doFilter(ContourConcurrentSessionFilter.java:36)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
com.jamasoftware.contour.view.filter.GzipFilter.doFilter(GzipFilter.java:51)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:168)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
Root Cause

java.lang.OutOfMemoryError: PermGen space
org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.getTypeAnnotationWalker(BinaryTypeBinding.java:524)
org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.cachePartsFrom(BinaryTypeBinding.java:406)
org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.createBinaryTypeFrom(LookupEnvironment.java:698)
org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.createBinaryTypeFrom(LookupEnvironment.java:681)
org.eclipse.jdt.internal.compiler.Compiler.accept(Compiler.java:299)
org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.askForType(LookupEnvironment.java:166)
org.eclipse.jdt.internal.compiler.lookup.PackageBinding.getTypeOrPackage(PackageBinding.java:201)
org.eclipse.jdt.internal.compiler.lookup.Scope.getPackage(Scope.java:2981)
org.eclipse.jdt.internal.compiler.ast.QualifiedTypeReference.getTypeBinding(QualifiedTypeReference.java:97)
org.eclipse.jdt.internal.compiler.ast.TypeReference.internalResolveType(TypeReference.java:472)
org.eclipse.jdt.internal.compiler.ast.TypeReference.resolveType(TypeReference.java:571)
org.eclipse.jdt.internal.compiler.ast.TypeReference.resolveType(TypeReference.java:567)
org.eclipse.jdt.internal.compiler.ast.TypeReference.resolveSuperType(TypeReference.java:541)
org.eclipse.jdt.internal.compiler.lookup.ClassScope.findSupertype(ClassScope.java:1292)
org.eclipse.jdt.internal.compiler.lookup.ClassScope.connectSuperclass(ClassScope.java:938)
org.eclipse.jdt.internal.compiler.lookup.ClassScope.connectTypeHierarchy(ClassScope.java:1095)
org.eclipse.jdt.internal.compiler.lookup.CompilationUnitScope.connectTypeHierarchy(CompilationUnitScope.java:323)
org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.completeTypeBindings(LookupEnvironment.java:229)
org.eclipse.jdt.internal.compiler.Compiler.internalBeginToCompile(Compiler.java:746)
org.eclipse.jdt.internal.compiler.Compiler.beginToCompile(Compiler.java:383)
org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:428)
org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:580)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:385)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:358)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:345)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:660)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:400)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
Note The full stack trace of the root cause is available in the server logs.

Apache Tomcat/7.0.99
---------------------------------------------------------------------------------------------------------------------

HTTP Status 500 – Internal Server Error
Type Exception Report

Message Handler processing failed; nested exception is java.lang.OutOfMemoryError: PermGen space

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.springframework.web.util.NestedServletException: Handler processing failed; nested exception is java.lang.OutOfMemoryError: PermGen space
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:839)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:669)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:574)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
com.jamasoftware.contour.view.filter.CheckSetupFilter.doFilter(CheckSetupFilter.java:60)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:79)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:109)
com.jamasoftware.contour.view.filter.ContourConcurrentSessionFilter.doFilter(ContourConcurrentSessionFilter.java:36)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
com.jamasoftware.contour.view.filter.GzipFilter.doFilter(GzipFilter.java:51)
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:381)
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:168)
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
Root Cause

java.lang.OutOfMemoryError: PermGen space
Note The full stack trace of the root cause is available in the server logs.

Apache Tomcat/7.0.99.

Fix
Linux On terminal

# export JAVA_OPTS="-Xms1024m -Xmx10246m -XX:NewSize=256m -XX:MaxNewSize=356m -XX:PermSize=256m -XX:MaxPermSize=356m"

Fixed this error.