simple script to backup PostgreSQL database

Question

Hello I write simple batch script to backup postgeSQL databases, but I find one strange problem whether the pg_dump command can specify a password?

There is batch script:

 REM script to backup PostgresSQL databases
 @ECHO off

 FOR /f "tokens=1-4 delims=/ " %%i IN ("%date%") DO (

 SET dow=%%i
 SET month=%%j
 SET day=%%k
 SET year=%%l
 )

 SET datestr=%month%_%day%_%year%
 SET db1=opennms
 SET db2=postgres
 SET db3=sr_preproduction
 REM SET db4=sr_production

 ECHO datestr is %datestr%

 SET BACKUP_FILE1=D:\%db1%_%datestr%.sql
 SET FIlLENAME1=%db1%_%datestr%.sql

 SET BACKUP_FILE2=D:\%db2%_%datestr%.sql
 SET FIlLENAME2=%db2%_%datestr%.sql

 SET BACKUP_FILE3=D:\%db3%_%datestr%.sql
 SET FIlLENAME3=%db3%_%datestr%.sql

 SET BACKUP_FILE4=D:\%db14%_%datestr%.sql
 SET FIlLENAME4=%db4%_%datestr%.sql

 ECHO Backup file name is %FIlLENAME1% , %FIlLENAME2% , %FIlLENAME3% , %FIlLENAME4%

 ECHO off
 pg_dump -U postgres -h localhost -p 5432 %db1%  > %BACKUP_FILE1%
 pg_dump -U postgres -h localhost -p 5432 %db2%  > %BACKUP_FILE2%
 pg_dump -U postgres -h localhost -p 5432 %db3%  > %BACKUP_FILE3%
 REM pg_dump -U postgres -h localhost -p 5432 %db4%  > %BACKUP_FILE4%

 ECHO DONE !

Please give me advice

Regards Mick

Answer 1

You cannot specify a password for Postgres utilities like pg_dump on the command line.
This would be a giant security hole, requiring disgusting workarounds to mitigate.

What you CAN do is create a pgpass file, which pg_dump will consult.

Depending on your needs you may want to consider taking a filesystem level backup instead of using pg_dump -- pg_dump will need to lock various parts of your database while it runs, and may interrupt normal use of the system. Alternately, consider running your backup process on a slave system.

Answer 2

You can also create a dedicate user, restricted to localhost and with reduced privileges who can connect without password. (For example a unix user).

We used this and if the user is well protected it will not break the security.

Answer 3

Thanks for your cmd script. I used it to write my own as show below. It will backup all databases stored in postgresql to file formatted with the custom format used by pg_dump with date yyyymmdd_hhss in the name. ToDo : backup full schema without data.

The database name is stored in the %%d variable in the loop. You can change safely :

• "backup_data_dir" (must end by )
• "pg_user" (postgres by default)
• "pg_bin_dir" (must end by )

Attention : I'm french. dd/mm/yyyy for %date%, "DEBUT" for "START", "F I N" for "E N D".

@ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION
SET backup_data_dir=C:\path\to\backup\
SET backup_file_name=%COMPUTERNAME%.%date:~6,4%%date:~3,2%%date:~0,2%_%time:~0,2%%time:~3,2%.PGDMP
SET pg_user=--username=postgres
SET pg_dmp_option=--clean %pg_user% --format=custom
SET pg_lst_db=psql.exe %pg_user% --list --field-separator=^; --tuples-only --no-align
SET pg_bin_dir=C:\Program Files\PostgreSQL\9.6\bin\

CD /D %pg_bin_dir%
FOR /f "delims=; tokens=1" %%d IN ('!pg_lst_db!^| find ";"^|find /v "template0"') DO (
  @ECHO !date! !time! pg_dump de la base [%%d] --- DEBUT ---
  SET backup_file_name=%%d.%backup_file_name%
  SET pg_dmp_option=%pg_dmp_option% --file="%backup_data_dir%!backup_file_name!" --dbname=%%d
  pg_dump.exe !pg_dmp_option!
  ECHO !date! !time! pg_dump de la base [%%d] --- F I N ---
)