How to simplify automation: using environment variables

Automation does not have to be complex and can be as easy as using environment variables.

I have blogged about similar topics:
Simplify Oracle critical patch updates using simple configurations

The objective is to copy the last five trail files for each GoldenGate processes from source to destination.

Here are high level steps:

Copy files (rt*) to new destination:
1. export OLD_DIRDAT=/media/patch/dirdat
2. export NEW_DIRDAT=/media/swrepo/dirdat
3. export TRAIL_PREFIX=rt*
5. ls -l $NEW_DIRDAT
6. ls $OLD_DIRDAT/$TRAIL_PREFIX | head -5
7. ls $OLD_DIRDAT/$TRAIL_PREFIX | tail -5
8. cp -fv $(ls $OLD_DIRDAT/$TRAIL_PREFIX | tail -5) $NEW_DIRDAT
9. ls -l $NEW_DIRDAT/*

Copy files (jk*) to new destination:
export TRAIL_PREFIX=jk*
Repeat steps 5-9

DEMO:

[[email protected] ~]$ export OLD_DIRDAT=/media/patch/dirdat
[[email protected] ~]$ export NEW_DIRDAT=/media/swrepo/dirdat
[[email protected] ~]$ export TRAIL_PREFIX=rt*
[[email protected] ~]$ ls -l $NEW_DIRDAT
total 0
[[email protected] ~]$ ls $OLD_DIRDAT/$TRAIL_PREFIX | head -5
/media/patch/dirdat/rt01
/media/patch/dirdat/rt02
/media/patch/dirdat/rt03
/media/patch/dirdat/rt04
/media/patch/dirdat/rt05
[[email protected] ~]$ ls $OLD_DIRDAT/$TRAIL_PREFIX | tail -5
/media/patch/dirdat/rt06
/media/patch/dirdat/rt07
/media/patch/dirdat/rt08
/media/patch/dirdat/rt09
/media/patch/dirdat/rt10
[[email protected] ~]$ cp -fv $(ls $OLD_DIRDAT/$TRAIL_PREFIX | tail -5) $NEW_DIRDAT
‘/media/patch/dirdat/rt06’ -> ‘/media/swrepo/dirdat/rt06’
‘/media/patch/dirdat/rt07’ -> ‘/media/swrepo/dirdat/rt07’
‘/media/patch/dirdat/rt08’ -> ‘/media/swrepo/dirdat/rt08’
‘/media/patch/dirdat/rt09’ -> ‘/media/swrepo/dirdat/rt09’
‘/media/patch/dirdat/rt10’ -> ‘/media/swrepo/dirdat/rt10’
[[email protected] ~]$ ls -l $NEW_DIRDAT/*
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt06
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt07
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt08
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt09
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt10
[[email protected] ~]$
[[email protected] ~]$
[[email protected] ~]$ export TRAIL_PREFIX=jk*
[[email protected] ~]$ ls -l $NEW_DIRDAT
total 0
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 rt06
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 rt07
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 rt08
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 rt09
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 rt10
[[email protected] ~]$ ls $OLD_DIRDAT/$TRAIL_PREFIX | head -5
/media/patch/dirdat/jk45454
/media/patch/dirdat/jk45455
/media/patch/dirdat/jk45456
/media/patch/dirdat/jk45457
/media/patch/dirdat/jk45458
[[email protected] ~]$ ls $OLD_DIRDAT/$TRAIL_PREFIX | tail -5
/media/patch/dirdat/jk45456
/media/patch/dirdat/jk45457
/media/patch/dirdat/jk45458
/media/patch/dirdat/jk45459
/media/patch/dirdat/jk45460
[[email protected] ~]$ cp -fv $(ls $OLD_DIRDAT/$TRAIL_PREFIX | tail -5) $NEW_DIRDAT
‘/media/patch/dirdat/jk45456’ -> ‘/media/swrepo/dirdat/jk45456’
‘/media/patch/dirdat/jk45457’ -> ‘/media/swrepo/dirdat/jk45457’
‘/media/patch/dirdat/jk45458’ -> ‘/media/swrepo/dirdat/jk45458’
‘/media/patch/dirdat/jk45459’ -> ‘/media/swrepo/dirdat/jk45459’
‘/media/patch/dirdat/jk45460’ -> ‘/media/swrepo/dirdat/jk45460’
[[email protected] ~]$ ls -l $NEW_DIRDAT/*
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:59 /media/swrepo/dirdat/jk45456
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:59 /media/swrepo/dirdat/jk45457
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:59 /media/swrepo/dirdat/jk45458
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:59 /media/swrepo/dirdat/jk45459
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:59 /media/swrepo/dirdat/jk45460
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt06
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt07
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt08
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt09
-rwxrwxrwx 1 vagrant vagrant 0 Feb 20 16:58 /media/swrepo/dirdat/rt10
[[email protected] ~]$

In conclusion, automation does not have to be complex.

“Make things as simple as possible, but no simpler.”  Albert Einstein