Category: Linux

dnsmasq

Ubuntu point all .test domains to 127.0.0.1
Install dnsmasq on Ubuntu

February 25, 2018
Ubuntu point all .test domains to 127.0.0.1
Until recently .dev was popular TLD used by developers for local web development. Recently google acquired the rights to use .DEV domain name extension and forced SSL for this LTD in google chrome.

Web developers are looking for alternate home for their local development web sites. Some suggested .localhost as development LTD, but it is too large. Another option is .test, this is a reserved LTD, so you won’t be forced to leave and is short. So many opted for .test as local development domain extension.

DNSMasq allow you to point *.test domains to 127.0.01, so you don’t have to edit /etc/hosts and add each domain you need for local development.

To do this, create file
```
vi /etc/NetworkManager/dnsmasq.d/test
```
Add following
```
address=/.test/127.0.0.1
```
Restart network-manager.
```
service network-manager restart
```
We restarted network-manager as dnsmasq is started by Network Manager.

root@hon-pc-01:~# pstree -sp $(pidof dnsmasq)
systemd(1)───NetworkManager(11557)───dnsmasq(11594)
root@hon-pc-01:~#

dnsmasq
February 25, 2018

certbot certificates

To list all letsencrypt SSL certificates, run

certbot certificates

Example

root@ok:~# certbot certificates
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Revocation status for /etc/letsencrypt/live/boby.hosthat.com/cert.pem is unknown

-------------------------------------------------------------------------------
Found the following certs:
  Certificate Name: boby.hosthat.com
    Domains: boby.hosthat.com
    Expiry Date: 2017-06-11 15:10:00+00:00 (INVALID: EXPIRED)
    Certificate Path: /etc/letsencrypt/live/boby.hosthat.com/fullchain.pem
    Private Key Path: /etc/letsencrypt/live/boby.hosthat.com/privkey.pem
  Certificate Name: img.serverok.in
    Domains: img.serverok.in
    Expiry Date: 2018-05-02 16:06:53+00:00 (VALID: 66 days)
    Certificate Path: /etc/letsencrypt/live/img.serverok.in/fullchain.pem
    Private Key Path: /etc/letsencrypt/live/img.serverok.in/privkey.pem
  Certificate Name: lab.hostonnet.com
    Domains: lab.hostonnet.com
    Expiry Date: 2018-04-25 03:34:37+00:00 (VALID: 59 days)
    Certificate Path: /etc/letsencrypt/live/lab.hostonnet.com/fullchain.pem
    Private Key Path: /etc/letsencrypt/live/lab.hostonnet.com/privkey.pem
  Certificate Name: yboby.cf
    Domains: yboby.cf www.yboby.cf
    Expiry Date: 2018-03-21 19:43:49+00:00 (VALID: 25 days)
    Certificate Path: /etc/letsencrypt/live/yboby.cf/fullchain.pem
    Private Key Path: /etc/letsencrypt/live/yboby.cf/privkey.pem
-------------------------------------------------------------------------------
root@ok:~#

letsencrypt

February 24, 2018

Syntax error or access violation: 1071 Specified key was too long
When running database migration in a new larvel project, i get following error

boby@hon-pc-01:~/www/proxy (master)$ php artisan migrate

In Connection.php line 664:

SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes (SQL: alter table `users` add unique `users_email_unique`(`email`))

In Connection.php line 458:

SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes

boby@hon-pc-01:~/www/proxy (master)$

This is due to recent change in Lavral, that changed default charset to utf8mb4.

To fix this error, open file
```
vi app/Providers/AppServiceProvider.php
```
Find
```
use Illuminate\Support\ServiceProvider;
```
Add below
```
use Illuminate\Support\Facades\Schema;
```
Find
```
    public function boot()
    {
        //
    }
```
Replace with
```
    public function boot()
    {
        Schema::defaultStringlength(191);
    }
```
February 24, 2018
iptables
To list current rules, run
```
iptables -S
```
Or
```
iptables -L
```
To list rules in numeric format, run
```
iptables -nvL
```
Or
```
iptables -L -n
```
To view nat rules
```
iptables -t nat -L -n --line-number
```
To see rules with counter, use
```
iptables -L -n -v
```
Open port 80
```
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
```
To open port 8080 in iptables firewall, run
```
iptables -A INPUT -m state --state NEW -p tcp --dport 8080 -j ACCEPT
```
Open Port Range
```
iptables -A INPUT -p tcp --match multiport --dports 50000:60000 -j ACCEPT
```
Whitelist an IP
```
iptables --append INPUT --protocol tcp --source 64.57.102.34 --jump ACCEPT
```
Forward a Port to Another

All request on port 80 will get forwarded to port 7080
```
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j DNAT --to-destination :7080
```
Saving IP tables

Above IP table commands take effect immediatly, but they get lost when you reboot the PC. To make it permanent, run
```
service save iptables
```
You can also use
```
iptables-save > /etc/sysconfig/iptables
```
Related config are saved in
```
/etc/sysconfig/iptables
/etc/iptables/iptables.rules
```
Before Flush

Make sure all Chains are set to ACCEPT, if DROP, run
```
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -F
```
February 24, 2018
mosquitto
mosquitto is an Open Source MQTT server. MQTT is a machine to machine or IOT (Internet of Things) protocol.

https://mosquitto.org

To install run
```
apt-get install mosquitto mosquitto-clients
```
To test, run
```
mosquitto_sub -h localhost -t test
```
To create a user, run
```
mosquitto_passwd -c /etc/mosquitto/passwd USER_NAME
```
Config file available at
```
/etc/mosquitto/conf.d/default.conf
```
To restart, use
```
systemctl restart mosquitto
```
To connect with user and password, use
```
mosquitto_sub -h localhost -t test -u "USER_NAME" -P "PASSWORD"
```
February 22, 2018
Installing nvm (Node.js Version Manager)
nvm is a node version manager, which allows you to run multiple versions of node.js

To install nvm, run
```
curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.8/install.sh | bash
```
To list all available node versions, run
```
nvm ls-remote
```
To install a particular node.js version, run
```
nvm install 22
```
To activate/select a node.js version, use
```
nvm use 22
```
To set default node,.js version, run
```
nvm alias default 22
```
to list all installed node.js versions
```
nvm ls
```
The versions with N/A are not installed.

nodejs
February 22, 2018
Magento
https://vuestorefront.io – store front for magento.

Magento 2
Magento 2 Login Errors
- Magento 2 Your session has expired
- Magento 2 Your password has expired
Magento version

To find the version, go to

https://URL/magento_version

Magento 1.9
February 21, 2018
Cronjob for Magento 1.9
To set cronjob for Magento 1.9, add
```
*/3 * * * * /bin/sh /var/www/html/cron.sh
```
Magento
February 21, 2018
CakePHP
After moving CakePHP application from one server to another with different DocumentRoot, site still try to load file from OLD directory. To fix this, delete the file
```
rm tmp/cache/persistent/myapp_cake_core_file_map
```
Once deleted, this file get auto created with new paths.
February 21, 2018

Backup Webite to Amazon S3

Create file

mkdir /usr/serverok/
vi /usr/serverok/backup-daily.sh

Add

#!/bin/bash
 
BACKUP_FILE="backup-`date +%Y-%m-%d`.tgz"
/bin/tar --exclude-tag-under=no-backup -zcvhf /backup/$BACKUP_FILE /var/www/html/

aws s3 cp /backup/$BACKUP_FILE s3://S3_BUCKET_NAME/
rm -f /backup/$BACKUP_FILE

Make the file executable

chmod 755 /usr/serverok/backup-daily.sh

Set it run everyday with cronjob

@daily /usr/serverok/backup-daily.sh  > /var/log/backup-daily.log 2>&1

To backup MySQL database, use

https://serverok.in/mysqldump-backup

See Backup

February 19, 2018

logrotate
logrotate is a program to rotates logs. This is run daily using cronjob
```
/etc/cron.daily/logrotate
```
Logrotate config files are stored in
```
/etc/logrotate.d/
```
To rotate logs daily, add daily to the logrotate configuration. To keep logs for 5 days, add “rotate 5”.

Rotating a log

To rotate a log
```
/var/log/sync-servers.log
```
Create file
```
vi /etc/logrotate.d/sync-servers
```
with content
```
/var/log/sync-servers.log
{
	create 640 root adm
	missingok
	notifempty
	rotate 4
	weekly
}
```
logrotate nginx log by date
February 14, 2018

Category: Linux

Magento 2 Login Errors

Rotating a log