M-AB.sh

#Copyright (c) 2021 M-AB

#All Rights Reserved.
#This program is free software; you can redistribute it and/or modify
#it under the terms of the GNU General Public License, version 2.0,
#as published by the Free Software Foundation.
#This program is also distributed with certain software (including
#but not limited to OpenSSL) that is licensed under separate terms,
#as designated in a particular file or component or in included license
#documentation.  The authors of M-AB hereby grant you an additional
#permission to link the program and your derivative works with the
#separately licensed software that they have included with M-AB.

### Written by Ankit Kapoor

#!/bin/bash

### This script will install the mysqld from the binary files.User can download the binary files
### from the mysql official website. Only condition for this script to work is that the tar or zipped file should be untar and the folder should be in a place.
### This script will start from creating the group and user and if already exist will skip to the next path where it will create the data directory,log directory 
### and the configuration file after taking input from the user.


########### Step 0 to check if there is already an existing process of mysql  ######################

echo "Checking if mysqld is already running on this system"
is_running=yes
ps cax | grep mysql > /dev/null
if [ $? -eq 0 ];
  then
  echo "mysqld is already running."
  echo "Do you want to kill this process and re-install database"
        read input
         if [ "${input^^}" == "${is_running^^}" ];
            then
            id=$(ps cax | grep mysql | grep -o '^[ ]*[0-9]*')
            echo $id && kill $id
            result=$?
              if [ "$result" = 0 ];
                 then
                 echo "mysqld process has been killed successfully"
                 else
                 echo "cannot kill, please kill manually and re-run this script"
                 echo "exiting program"
                 exit 1
               fi
            echo "Proceeding towards the installation"
            else
            echo "exiting this programm"
            exit 1
         fi
   else
   echo "Process is not running and hence proceed towards the installation"
fi


sleep 3


############# Step 1 is to check if mysql group exist ####################
b=mysql

echo "Checking if group "$b "already exist and if not create one........."  

a=$(grep mysql /etc/group | cut -d : -f 1)
if [ "$a" = $b ];
   then
     echo "Group "$b "already exist"
   else
     echo "Group "$b "not exist and thus adding..."
     groupadd mysql
     result=$?
      if [ "$result" = 0 ];
       then
         echo "group succesfully added"
       else
         echo "group addition failed"
      fi
fi

sleep 2

########### Step 2 is to create the user mysql and add it to the group mysql################

echo "Now Add user "$b

useradd -r -g $b $b 2>/dev/null
result=$?

 if [ "$result" = 0 ];
    then
    echo "user succesfully added to the group "$b
    else
    echo "user already existing"
 fi

sleep 2

############## Step 3 is to create the data directory, log file directory, configuration file with minimum parameters required to start mysqld #################

echo "Enter the data directory path.For example /data01/"
read  dpath

until mkdir $dpath 2>/dev/null 
  do    
      mkdir $dpath 2>/dev/null
      echo "this path already exist. Please try again"
      read  dpath
 done
chmod -R 750 $dpath && chown -R mysql:mysql $dpath
echo "Data directory created and permission and ownership assigned"

sleep 2

echo "Now creating the log file directory where error file exist. Please enter the log directory.For example /log01"
read lpath

until mkdir $lpath 2>/dev/null
  do
      mkdir $lpath 2>/dev/null
      echo "this path already exist. Please try again"
      read  lpath
  done

  echo "creating log error file now...."
  touch $lpath/error.log && chmod -R 750 $lpath && chown -R mysql:mysql $lpath
  echo "created successfully"
  echo "log directory successfully created, permission and ownership assigned"


sleep 2

echo "cnf file will be created in the /etc folder for ease of understanding and user can move it to another location if required....."
echo "creating now...."

touch /etc/my.cnf
  result=$?
  if [ "$result" = 0 ];
     then
      echo "cnf file succesfully created adding parameters now"
      a="[mysqld]"
      b="user=mysql"
      c="datadir=$dpath"
      d="log-error=$lpath/error.log"
      echo -e "$a\n$b\n$c\n$d" > /etc/my.cnf
    else
     echo "configuration file not created..."
  fi
sleep 2

######## Step 4 ################### 

echo "Now mysql database will install.Installing........"
echo "please provide the path to the mysql bin folder. For example /mysql-8.0.23-linux-glibc2.12-x86_64/bin"
read mysqld
echo "database installing........."
$mysqld/mysqld --datadir=$dpath --initialize --user=mysql

   if [ "$result" = 0 ];
      then
        echo "database has been successfully installed under "$dpath
      else
        echo "Database creation failed please check..."
   fi
sleep 3

########## Step 5 ###################

echo "initialising database..........."
nohup $mysqld/mysqld_safe --defaults-file=/etc/my.cnf --user=mysql > /dev/null 2>&1 &
result=$?
 if [ "$result" = 0 ];
    then
     echo "Database has been initialised successfully"
    else
     echo "Not installed...Error in installing"
 fi

sleep 2
########## Step 6 ###################

######## to change the password #######

rpassword=$(grep -w "A temporary password is generated for root@localhost" $lpath/error.log | cut -d " " -f 13)
echo "Your password is "$rpassword
echo "Login into database using mysql -uroot -p'"$rpassword"'and change the password using alter user root@localhost identified by 'your password'; and then followed by 'flush privileges;'"
sleep 2
echo "exiting now...."