Tag: programming

How to Update Context in Odoo

You may want to pass some data to a specific page in Odoo, and change the fields based on those data. In those cases, you want to use Context. Context is a data structure passed to the request object that contains hidden values, and can be used to change results of the page.

Context is a frozendict data type in Odoo. That’s why you can change it like you do in a dict data type, for example:

dict_object.update({
'test': 'test_value',
})

As the Context is frozendict, it won’t take such changes. Odoo provides a way to change values, it’s called ‘with_context’. The syntax is as following:

self = self.with_context({
'test': 'test_value',
})

This one should rewrite the context available in the self object by adding the new key:value pair you have mentioned. There are times, this might not work as expected, and you want a patch technique to update the context. This can be done by changing the data type to dict.

self.env.context = dict(self.env.context)
self.env.context.update({
'test': 'test_value',
})

This would also add the new key:value pair to your context and work as expected. There is almost no security concern here for converting the frozendict as the context will destroy once the page is left soon enough.

How To: Use SSH Password in a Script

You can obviously use RSA public/private keypair to access servers without password, although, sometimes, it may be desirable to use ssh password on a command line and run a remote command on another server. This can be done using a tool called ‘sshpass’. You can create a simple bash script using sshpass, that can help you monitor and control multiple servers from a single location.

How to use ssh password in script

First install sshpass:

# yum install sshpass -y

Once done, you can use sshpass command as following:

# sshpass -p "SSH_Password" ssh -o StrictHostKeyChecking=no SSH_Username@remote-ssh-server "yourcommand"

Just replace, the password, username, remote-ssh-server and your command with your desired setup, and viola!

Note: If yum says, the following:

No package sshpass* available.

then you would need to install epel repository to install sshpass. To install epel, run the following:

# yum install epel* -y

Programming: How To Check if an IP is Available or Not in Bash

How To Check if an IP is Available or Not in Bash

A quick trick I use is ‘ping’ command. PING will return 0 on success and 1 or above on failure while using it with -c 1 (Means only one ICMP packet). That makes it useful to use with a if condition shell code as following:

if ping -c 1 -w 5 192.168.2.1 >/dev/null
then
echo "IP Available"
else
echo "IP Not Available"

Programming: How to Check If A File Exists or Not in Bash Script

How to Check If A File Exists or Not in Bash Script

You can use if condition in bash script to do that. If conditions takes ‘-f’ to test if a file exists or not. Syntax would be the following:

$FILE = $1
if [ -f $FILE ]; then
echo "File Exists"
else
echo "File Do Not Exist"
endif

Now, if your script only demands to check if the file do not exist, you can use a unary operator for negate the boolean value as following:

$FILE = $1
if[ ! -f $FILE ]; then
echo "File Do Not Exist"
endif

 

Programming: Laravel Error – Specified Key Was Too Long

A common error I have seen users reporting using Laravel, is the following:

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

The error actually happens because Laravel 5.5 assumes you have MySQL 5.7.7 or above. While on MySQL 5.7.7 the key size was increased than the older versions.

How to fix laravel Specified key was too long

To fix this, find the AppServiceProvider.php file under app/Providers folder, and add the following line before start of the class:

use Illuminate\Support\Facades\Schema;

Then, inside the boot() method under the class, add the following line:

Schema::defaultStringLength(191);

If you restart your laravel migration or the query, it should work fine now.