Small sed cheatsheet

Sed is a brilliant function to delete or replace strings. I often used sed for replacing (a group of) words or deleting lines.

How to remove a line containing a string in sed:

sed -i '/string/d' /home/admin/filename.txt

How to replace a string in sed:

sed -i 's/#Port 22/Port 12340/g' /etc/ssh/sshd_config

How to remove white lines from ie a .ini file with sed:

sed -i '/^\s*$/d' /usr/local/directadmin/conf/directadmin.conf

Bash commands to see server stats

I found this little snippet elsewhere and find it very usefull to use in my own scripts for statistiscs:

free -m | awk 'NR==2{printf "Memory Usage: %s/%sMB (%.2f%)\n", $3,$2,$3*100/$2 }'
df -h | awk '$NF=="/"{printf "Disk Usage: %d/%dGB (%s)\n", $3,$2,$5}'
top -bn1 | grep load | awk '{printf "CPU Load: %.2f\n", $(NF-2)}'

It returns something like:

Memory Usage: 2340/24000MB (9.75%)
Disk Usage: 40/100GB (40%)
CPU Load: 0.04

Bash script to make MySQL back-ups

This simple but effective script makes a back-up of the target SQL database and deletes databases older then 90 days. I keep the folder synchronized with other systems so the customer can reach his database with 90 days retention himself.

#!/bin/bash

cd /backups

user="mysql_user"
passwd="password"
host="localhost"
db_name="mysql_database"

backup_path="/backups"
date=$(date +"%d-%b-%Y")

umask 177

# dump the database
mysqldump --user=$user --password=$passwd --host=$host $db_name > $backup_path/$db_name-$date.sql

# zip contents
zip $db_name-$date.zip $db_name-$date.sql

# remove old backups
find $backup_path/* -mtime +90 -exec rm {} \;

echo done

 

Of course, instead of setting the username/passwd variables in the script itself you can read the DirectAdmin credentials with:

source /usr/local/directadmin/conf/mysql.conf

Bash script to migrate Magento to DirectAdmin via rsync

Migrating Magento is pretty easy. Most of the times you only need to sync the files and export/import the database. But to automate such a process to test a lot, you can use a bash script to make things easier.

I often use this bash script (or similar) to migrate a Magento shop from one server to another:

#!/bin/bash

echo dumping sql
ssh root@10.0.0.1 -p 7685 "mysqldump -u magento_user -ppassword magento_db > /home/magento.sql"

echo rsync files
/usr/bin/rsync --exclude 'app/etc/local.xml' --exclude 'media/.htaccess' --exclude 'app/etc/config.xml' -a --delete -e "ssh -p 7685" root@10.0.0.1:/home/domain.com/. /home/user/domains/domain.com/public_html/.

echo rsync db
/usr/bin/rsync -a --delete -e "ssh -p 7685" root@10.0.0.1:/home/magento_db.sql /home/user/domains/domain.com/

echo importing db
source /usr/local/directadmin/conf/mysql.conf
mysql -u $user -p$passwd new_magentodb < /home/user/domains/domain.com/magento.sql

echo restoring permissions
chown -R user:user /home/user/domains/domain.com/public_html
chown user:user /home/user/domains/domain.com/magento.sql

echo done

This script is executed on the new server, which is loaded with DirectAdmin. The old server (10.0.0.1) is plain CentOS 6.5. I added the rsa-key.pub to the authorized keys on the old server, so this server is able to execute commands as root without entering a password.

The port on the old server is 7685, that’s why you find it in the ssh and rsync commands.

I exclude the local.xml because on the new server I had to change the MySQL credentials. The media/.htaccess file gave problems on the new DirectAdmin server as well, so I had to change it and exclude the file from future rsyncs.

After running this script the Magento webshop is migrated from the old server to the new DirectAdmin server and works perfectly!

 

WordPress update error: download failed

Sometimes WordPress can’t update itself or the plug-ins. This often happens after the installation has been moved or the username has been changed.

Downloading update from https://downloads.wordpress.org/release/wordpress-4.3.1-no-content.zip…

Download failed.: Destination directory for file streaming does not exist or is not writable.

Installation Failed

The solution is to fix the WP_TEMP_DIR in the wp-config.php. The full path looks like this on a DirectAdmin server:

define('WP_TEMP_DIR', '/home/username/domains/example.com/public_html/wp-content/uploads');

If the folder exists, and is writable for your user, WordPress will be able to update itself again.

DirectAdmin SQL back-ups via commandline

This is how to make a SQL only back-up via commandline in DirectAdmin. The first line puts the command in the task.queue. The second line runs the task queue and will show the output. The d400 means debug level 400.

echo "action=backup&append%5Fto%5Fpath=nothing&database%5Fdata%5Faware=yes&email%5Fdata%5Faware=yes&local%5Fpath=%2Fhome%2Fadmin%2Fmysql%5Fbackups&option%30=database&option%31=database%5Fdata&owner=admin&type=admin&value=multiple&what=select&when=now&where=local&who=all" >> /usr/local/directadmin/data/task.queue
/usr/local/directadmin/dataskq d400

When the back-up is completed you will receive an e-mail via the normal DirectAdmin message system.

The back-ups will be stored in /home/admin/mysql_backups

How to install/repair Installatron

This is how to install Installatron on a Centos server:

wget http://data.installatron.com/installatron-plugin.sh
chmod +x installatron-plugin.sh
./installatron-plugin.sh -f

 

If the normal install gets stuck, or your current installation is broken, try this full repair command:

rm -fr /usr/local/installatron/lib /usr/local/installatron/etc/php.ini 
curl -O http://data.installatron.com/installatron-plugin.sh 
chmod 755 installatron-plugin.sh 
./installatron-plugin.sh -f --stable 
rm -f /var/installatron/data.db /var/installatron/data.db-* 
/usr/local/installatron/installatron --repair --recache 
/usr/local/installatron/installatron --send-update-report