Всякие заметочки

2021/02/15

Qualys SSL Labs

Interesting service to test your site's SSL certificate and configuration on Qualys SSL Labs. Check it out:

https://www.ssllabs.com/ssltest/

ansible 2.10.5: ansible-vault requires either the cryptography library (preferred) or pycrypto in order to function

Good day! :)

After the last installation of Ansible on Ubuntu 20.04, an error occurs when launching ansible-vault:

-> % lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 20.04.1 LTS
Release:        20.04
Codename:       focal
-> % ansible --version  
ansible 2.10.5
  config file = /home/null/ansible-autoconnex/ansible.cfg
  configured module search path = ['/home/null/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/null/.local/lib/python3.9/site-packages/ansible
  executable location = /home/null/.local/bin/ansible
  python version = 3.9.0+ (default, Oct 20 2020, 08:43:38) [GCC 9.3.0]
-> % ansible-vault edit users.yml
ERROR! ansible-vault requires either the cryptography library (preferred) or pycrypto in order to function. for /home/null/ansible-autoconnex/users.yml

The problem is the lack of cffi library. Most likely the developers forgot to specify the dependency somewhere. Just install cffi.

-> % pip install cffi

2020/10/21

– "There is no such thing as public money; there is only taxpayers’ money". (Margaret Hilda Thatcher).

2020/10/09

Classless IN-ADDR.ARPA delegation and dynamic reverse DNS UPDATE

Link: Classless IN-ADDR.ARPA delegation and dynamic reverse DNS UPDATE

2020/10/08

Disaster

2020/09/04

Linux ate my RAM

Links:
https://www.linuxatemyram.com/
Interpreting /proc/meminfo and free output for Red Hat Enterprise Linux 5, 6 and 7
Red Hat Enterprise Linux Oracle Tuning Guide
How to Check Memory Usage From the Linux Terminal
What Is Swappiness on Linux? (and How to Change It)
https://www.kernel.org/doc/Documentation/filesystems/proc.txt
https://www.kernel.org/doc/Documentation/sysctl/vm.txt

2020/08/12

LENS QUALITY: MTF, RESOLUTION & CONTRAST

Link: https://www.cambridgeincolour.com/tutorials/lens-quality-mtf-resolution.htm