SyntaxHighlighter JS

2018-10-29

Ruby on Rails json LoadError

Problem:
Running Ruby on Rails 'bin/rails s' and you get an error

in require: cannot load such file -- json (LoadError)


Solution:
Edit the Gemfile and add

gem 'json'


Installing Ruby on Rails on AWS Linux

To install Ruby on Rails on the AWS Linux VM, you need to install some prerequisites first.

sudo su -
yum install -y ruby24
alternatives --set ruby /usr/bin/ruby2.4
yum install -y ruby24-devel rubygems ruby24-devel gcc zlib-devel patch sqlite-devel
curl -sL https://rpm.nodesource.com/setup | bash -
yum install -y nodejs

gem install rails
rails --version

2018-10-26

Add hard disk to VMware CentOS 7 VM

There are two easy steps to add a hard disk for a a VMware CentOS 7 VM

  1.  Assign a new hard disk in VMware vSphere
  2.  Configure the new hard disk in CentOS
See the full picture tutorial at
https://dev.to/juttayaya/add-hard-disk-to-vmware-centos-7-vm-22m8

2018-10-25

Get the original username of sudo

For auditing and logging purposes, I needed to get the original Unix login username and not the sudo account name.

The Unix command to get the original login username is

logname 

With the logname command, the operator can su and sudo to various accounts and it will still display the original login.

To try it on a Unix prompt

sudo su - oracle
echo My sudo id is $(whoami) and my login id is $(logname)

Output:
My sudo id is oracle and my login id is juttayaya



Reference:https://stackoverflow.com/questions/4598001/how-do-you-find-the-original-user-through-multiple-sudo-and-su-commands

2018-02-04

MacBook Pro 2012 broken GPU fix

I have a 17" 2011 MacBook Pro that suffers from the notorious GPU video failure (https://www.bit-tech.net/news/tech/laptops/apple-admits-gpu-design-flaw/1/)

Here is the work-around to turn off the GPU. Credit to PeytonPlaysMc

  1. Boot into Recovery Mode
    Hold Command+R+S keyboard buttons while pressing the power button
  2.  Disable System Integrity Protection (SIP)
     
    Type on the command prompt
    csrutil disable
  3. Reboot MacBook Pro into Single User mode
    Type on the command prompt
    reboot
    Then hold Command+S keyboard buttons
  4. Hard disk check
    Type on the command prompt
    /sbin/fsck -fy
  5. Mount root file system in read-write mode
    Type on the command prompt
    /sbin/mount -uw /
  6. Make a directory to save the AMD drivers
    Type on the command prompt
    mkdir /AMD_save
  7. Move AMD drivers to the save directory
    Type on the command prompt
    mv /System/Library/Extensions/AMD* /AMD_save
  8. Delete AMD driver cache
    Type on the command prompt
    rm -rf /System/Library/Caches/com.apple.kext.caches/
  9. Create AMD drive cache directory

    Type on the command prompt
    mkdir /System/Library/Caches/com.apple.kext.caches/
  10. Force refresh of drive cache
    Type on the command prompt
    touch /System/Library/Extensions/
  11. Reboot MacBook Pro to normal mode. Graphics will run slow at this point

    Type on the command prompt
    reboot
  12. Boot into Recovery Mode
    Restart MacBook Pro while holding Command+R+S
  13. Enable System Integrity Protection (SIP)
     
    Type on the command prompt
    csrutil enable
  14. Reboot MacBook Pro to normal mode.Type on the command prompt
    reboot
  15. Launch Terminal in UI and type
    sudo nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00
  16. Restart MacBook Pro one final time