Uly.me

cloud engineer

user

Useradd With Specific uid and guid

Here’s the command to create a Linux user with a specific user id and group id.

sudo groupadd -r -g 1234567 username
sudo useradd -r -u 1234567 -g 1234567 -m -d /home/username -s /bin/bash nexus -c "my new account"

Vintela Troubleshooting

Vintela is a utility for allowing AD users to login to Linux. Here are some basic troubleshooting tips.

#check version
vastool -v
# check status
vastool status
# start stop script
/etc/init.d/vasd start/stop/restart
# check user access
vastool user checkaccess username
# list users
vastool list users
# flush cache
vastool flush
# unjoin domain 
vastool unjoin -f -l
# join domain
vastool -u username@domain.com -w password join -f -c OU=Linux,OU=linux,OU=Servers,DC=domain.com,DC=net domain.com

Important files.

/etc/opt/quest/vas/host.keytab      Encrypted host key
/etc/opt/quest/vas/group-override   Maps accounts to groups
/etc/opt/quest/vas/users.allow      Lists groups that are granted access to the server
/etc/opt/quest/vas/xjoin.keytab     File used to join server to domain
/etc/opt/quest/vas/vas.conf         Primary VAS configuration file
/etc/opt/quest/vas/user-override    Allows you to override specific user settings

Add Existing User To A Group

Here’s how to add an existing user to a user group in Linux.

usermod -a -G groupname username
usermod -a -G www-data john

List all users belonging to a group.

lid -g www-data

List all the groups the user belongs to.

groups john

Change MySQL User Password

This is a very simple command to run. Login to MySQL first and run the following the command line.

ALTER USER username IDENTIFIED BY 'password';

Flush privileges for changes to take effect.

flush privileges;

WordPress Read Only

Here’s how to create a WordPress site that’s read only. You will not be able to create, update and delete posts.

  1. Login to MySQL or MariaDB.
  2. Choose mysql database.
  3. Create a new user called ‘wpro’ for WordPress read only.
  4. Grant select permissions to all tables in ‘wordpress’ database.
  5. Flush privileges to commit your changes.
mariadb -u root -p
use mysql;
create user 'wpro'@'localhost' identified by 'yourpassword';
grant select on wordpress.* to 'wpro'@'localhost';
flush privileges;

In MySQL or MariaDB, you have to terminate all commands with a semicolon.

Now edit your WordPress wp-config.php file. vim /var/www/wordpress/wp-config.php.

/** MySQL database username */
define('DB_USER', 'wpro');
 
/** MySQL database password */
define('DB_PASSWORD', 'yourpassword');

After saving the wp-config.php file, everything should work just like before, except that you will not be able to save, publish or delete posts, pages, or add or delete media files to your WordPress site. It’s working as intended.

Check If Domain Joined

Here’s the command to check if instance is domain joined.

realm discover domain.com

To check if AD user is working.

id user@ad.example.com

To check if AD group is working.

getent group ad-group

IAM List Access Keys

Here’s how to list all the access keys in AWS via Python.

import logging
import boto3
from botocore.exceptions import ClientError
 
# set aws profile
session = boto3.Session(profile_name="default")
 
# get list of users
 
iam = session.client('iam')
users = iam.list_users()
 
# display results
print("{0:<20} {1:<25} {2:<15} {3:<10}".format('UserName', 'AccessKey', 'Status', 'CreateDate'))
print("----------------------------------------------------------------------------------------")
 
for a in users['Users']:
    user = a['UserName']
    # get keys
    keys = iam.list_access_keys(UserName=user)
    for b in keys['AccessKeyMetadata']:
        username = b['UserName']
        accesskeyid = b['AccessKeyId']
        status = b['Status']
        createdate = str(b['CreateDate'])
        print("{0:<20} {1:<25} {2:<15} {3:<10}".format(username, accesskeyid, status, createdate))