postgres backup with WAL - postgresql

Question

i am in no way a db admin, so please don't shoot me if i'm doing it completly wrong ...
I have to add some archiving to a productive postgres database (newest version in docker container) and trying to build some scripts to use with WAL.
The idea is to have a weekly script, that does a full backup to a new directory and then creates a symlink to this new directory that is used by the WAL script to write it's logs. Also the weekly script will delete old backups older than 30 days.
I would be very happy for any comments on this...
db settings
wal_level = replica
archive_mode = on
archive_command = '/archive/archive_wal.sh "%p" "%f"'
archive_timeout = 300
weekly script:
#!/bin/bash
#create base archive dir
#base_arch_dir=/tmp/archive/
base_arch_dir=/archive/
if [ ! -d "$base_arch_dir" ]; then
mkdir "$base_arch_dir"
chown -R postgres:postgres "$base_arch_dir"
fi
#create dir for week
dir="$base_arch_dir"$(date '+%Y_%m_%d__%H_%M_%S')
if [ ! -d "$dir" ]; then
mkdir "$dir"
chown -R postgres:postgres "$dir"
fi
#change/create the symlink
newdir="$base_arch_dir"wals
ln -fsn "$dir" "$newdir"
chown -R postgres:postgres "$newdir"
#do the base backup to the wals dir
if pg_basebackup -D "$newdir" -F tar -R -X fetch -z -Z 9 -U postgres; then
find "$base_arch_dir"* -type d -mtime +31|xargs rm -rf
fi
crchive script:
#!/bin/bash
set -e
arch_dir=/archive/wals
arch_log="$arch_dir/arch.log"
if [ ! -d "$arch_dir" ]; then
echo arch_dir '"$arch_dir"' does not exist >> "$arch_log"
exit -1
fi
#get the variables from postgres
p=$1
f=$2
if [ -f "$arch_dir"/$f.xz ]; then
echo wal file '"$arch_dir"/$f.xz' already exists
exit -1
fi
pxz -2 -z --keep -c $p > "$arch_dir"/$f.xz
Thank you in advance

Answer 1

It's not terribly difficult to put together your own archiving scripts, but there are a few things you need to keep track of, because when you need your backups you really need them. There are some packaged backup systems for PostgreSQL. You may find these two a good place to start, but others are available.
https://www.pgbarman.org/
https://pgbackrest.org/