Install tomcat and Apache centos 7

yum install gcc-c++

yum install openssl-devel.x86_64

cd /usr/local/src

wget wget wget

tar xvfz apr-1.5.1.tar.gz

tar xvfz apr-util-1.5.3.tar.gz

tar xvfz httpd-2.4.18.tar.gz

tar xvf pcre-8.35.tar.bz2

cd /usr/local/src/apr-1.5.1

./configure –prefix=/usr/local/apr


make install

cd /usr/local/src/apr-util-1.5.3

./configure –prefix=/usr/local/apr-util –with-apr=/usr/local/apr


make install

cd /usr/local/src/pcre-8.35

./configure –prefix=/usr/local


make install

cd /usr/local/src/httpd-2.4.18

./configure  –prefix=/usr/local/apache \

–enable-rule=SHARED_CORE  \


Harden the Apache Web Server on CentOS 7

Harden the Apache Web Server on CentOS 7

[root@clusterserver1 conf]# yum install httpd Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: * epel: * extras: * updates: Resolving Dependencies –> Running transaction check —> Package httpd.x86_64 0:2.4.6-40.el7.centos will be installed –> Finished Dependency Resolution

Dependencies Resolved

========================================================================================================================== Package                  […]

HDFS Command Syntax

HDFS Command Syntax Overview: hadoop fs : Ex.: hadoop fs -ls  hadoop version : check hadoop installed properly

HELP: help [cmd]: hopefully this is self-describing 

Inspect files: ls/lsr : list all files in cat : print on stdout tail [-f] : output the last part of the test : return attributes of file and […]

keytool commands

Public and private keys from a Java Key Store Step 1: Creating the “public-private” key-pair. keytool -genkey -alias client -validity 365 -keystore keystore.jks 

Step 2: Validate the “public-private” key pair. keytool -list -v -keystore keystore.jks

Step 3: Extract the “public key” from the “public-private” keytool -export -alias client -keystore keystore.jks -rfc -file public.cert

Step 4: […]


Technically at the moment there isn’t anything really wrong with the SHA-1 hash function, but it is now quite old and is starting to show potential cracks. Hence the reason that the security industry is advising to move to something better. In this case SHA-256.

1. Generate a SSL Key File

Firstly you will need […]

OpenSSL Commands

OpenSSL Commands

After you applied for a personal or a host certificate, you may need to export the bundle from your browser and convert them into a different format to be able to use them in tools like GSI-SSH in order to authenticate yourself to the grid, and also to be able to install your […]