DBA Scripts coding considerations for best compatibility to any platform

Did you find yourself trying to convert your DBA scripts to work on other OS or UNIX flavors ?
This is a typical issue DBAs cope with, the solutions can be:
  1. Each system has its own best scripting code (PowerShell for windows, bash for Linux), let's keep some versions of the same code.
  2. Write the code in a common language for all systems
  • Shell: In the past I used the old Posix shell (sh) which exited in all Unix systems. These days I use bash as is very common. 
  • Perl: Oracle installation already has its own Perl, no need to install it.
  • Java: Oracle installation already has its own java, no need to install it.
  • Python: Python should be installed, but the libraries that can be used are huge, and you can write shorter code.
  1. Write in sql/plsql as much as you can, the external code will be minimal (cmd / sh).
  2. Work remotely from your convenient operating system, using your scripts written in the language you master.
  3. Use a few macros injected to your terminal.
  4. Why use scripts, I use Toad / Cloud Control - it is much easier.
  5. Leave me alone, I like typing the same commands over and over.
I use most of the above options :) but try to have one version of script.
I am writing in Bash, but have started moving to Python (for new and complicated needs).
Recently I had a need to work on Solaris. Because I believe in using one code for all, I started to modify my code with a lot of IFs.
Above that, I needed to adjust external utilities like "sed" and "awk" since they do not work the same (Solaris Vs Linux).
Luckily I found that from Solaris 11 there are built-in gnu commands which are compatible with Linux, that are located in a different directory and start with the letter "g": "sed" is "gsed", "awk" is "gawk" and so on.
I decided that the gnu utility commands will be a variable in all of my scripts. All scripts will call a master environment file that decides which version to use.
cat platform.env
platform=`uname -s`
case "$platform"
in
   "SunOS")  os=Solaris
             ORATAB=/var/opt/oracle/oratab
             AWK=gawk
             GREP=ggrep
             EGREP=gegrep
             SED=gsed
             HOST_NAME=$(hostname)
             DF=gdf
             FIND=gfind
             USER=${LOGNAME}           
             CAT=gcat
             CHOWN=gchown
             CHMOD=gchmod
             CP=gcp
             ECHO=gecho
             MKDIR=gmkdir
             CUT=gcut
             SUDO=/usr/local/bin/sudo
             ;;
   "Linux")  os=Linux
             ORATAB=/etc/oratab
             AWK=awk
             GREP=grep
             EGREP=egrep
             SED=sed
             HOST_NAME=$(hostname -f)
             DF=df
             FIND=find
             CAT=cat
             CHOWN=chown
             CHMOD=chmod
             CP=cp
             ECHO=echo
             MKDIR=mkdir
             CUT=cut
             SUDO=sudo
             ;;
   #"HP-UX")  os=hpunix;;
   #  "AIX")  os=aix;;
         *)  echo "Sorry, $platform is not currently supported." | tee -a $LOGFILE
             exit 1;;
esac
In my last blog I discussed about identifying $ORACLE_SID and $ORACLE_HOME Basics commands for DBA part 1 - finding instance.
Now we will see a generic script version which uses the variables above:
#!/bin/bash
export SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
source ${SCRIPT_DIR}/platform.env
if [ -f ${ORATAB} ]
then
    for ORA_SID in `${CAT} ${ORATAB} | ${GREP} -v ^'#' | ${GREP} -v ^$ | ${AWK} -F ":" ' { print $1 }' | uniq`
    do
        if [[ ! "${ORA_SID^^}" == *"ASM"* ]] && [[ ! "${ORA_SID^^}" == *"MGMTDB"* ]]
        then
                echo working on ${ORA_SID}
                export ORACLE_SID=${ORA_SID}
                export ORACLE_HOME=`${CAT} $ORATAB | ${GREP} ^${ORACLE_SID}: | ${GREP} -v "^#" | ${GREP} -v "^$" | ${CUT} -d":" -f 2`
                Put your code here, using the variables above
        fi
    done
fi
Please comment and tell us about your way of using DBA scripts
Yossi Nixon

Comments

Popular posts from this blog

Data Guard - Changing IP Addresses

Install Oracle Internet Directory (OID) in Standalone mode

Fixing & Registering ORACLE_HOMES in Central Inventory