Category Archives: Packages

I found two ways to configure the /etc/resolv.conf file to prevent it to be overridden by the system.

  1. Edit the base file under the resolv.conf.d file
sudo vim /etc/resolvconf/resolv.conf.d/base

and then add the nameservers to the file:

nameserver 8.8.8.8
nameserver 8.8.4.4

lastly, update resolvconf:

sudo resolvconf -u

2. Install dnsmasq and edit /etc/dnsmasq.conf to add the nameservers you want.

sudo apt install dnsmasq
and
vim /etc/dnsmasq.conf

Then restart the network services:

sudo service dnsmasq restart and
sudo service network-manager restart

You should be all set now.

References:
1. https://unix.stackexchange.com/questions/128220/how-do-i-set-my-dns-when-resolv-conf-is-being-overwritten

2. https://unix.stackexchange.com/questions/128220/how-do-i-set-my-dns-when-resolv-conf-is-being-overwritten/163506#163506

Cheers!

Advertisements

Static IP config with netplan (ubuntu)

If you use a modern Ubuntu distribution (the latest 18.04 LTS or 17.XX), you might have noticed that the package to configure the network changed.

Ubuntu changed to Netplan, that is more modern and relatively simpler to use. The file configuration for a static IP should be as follows.

# cat /etc/netplan/01-netcfg.yaml
network:
 version: 2
 renderer: networkd
 ethernets:
 eth0:
 dhcp4: no
 addresses: [YOUR.STATIC.IP.ADDRESS/24]
 gateway4: X.X.X.X
 nameservers:
 addresses: [YY.YY.YY.YY, 8.8.8.8]

Reference: I extracted the following information from  https://ppc64el.wordpress.com/2018/03/22/ubuntu-18-04-netplan/

Please visit the link above for more information (including the original /etc/network/interfaces format of the eth0 interface before the transition to netplan).

Cheers!

Install Silversearcher-ag on Ubuntu

The Silversearcher tool is a super fast search tool that gives you rich information when searching for a string through all your files.

To install it:

sudo apt install silversearcher-ag

The Github project page:

https://github.com/ggreer/the_silver_searcher

You can find answers about why it is so fast, a chance to collaborate and other info there.

Cheers!

VIM buffer commands

Commands from vim buffers can take long to get into our brains. Practice will lead to perfection… eventually.

Here are some tips to get them into memory faster:

Editor commands:    
  :e filename - Edit a file an existing file in a new buffer
  :sp filename - Open a file in a new buffer and split window
  :vs or :vsp Open a file in a new buffer and split window vertically 
  ctrl+ws - Split window to work in two places of the same file
  ctrl+wv - Split window vertically (and work in the same file)

Navigation commands:
  :bnext (or :bn) - go to next buffer
  :bprev (of :bp) - go to previous buffer
  :bd - delete a buffer (close a file)
  ctrl+ww - switch between windows
  ctrl+wq - Quit a window
    

With pictures to decorate this post:

vim_example1_call

Open up a new file called ‘example1’

vs_example2

With ‘example1’ open, type in ‘:vs example2’ to vertically split the window and edit a new file ‘example2‘. It will open up a new buffer to the left of ‘example1’

sp_example3

From the ‘example2’ buffer, type in ‘:sp example3’ to horizontally split the screen and edit a new file ‘example3‘. It will open a new buffer above ‘example2’

example3_text

All three buffers displayed. Use CTRL-W+W to cycle through them.

Cheers!

Reference: http://www.worldtimzone.com/res/vi.html

List gpg keys in your system

1.1. RPM based distros (RHEL, CentOS, Fedora)

Import:

$ sudo rpm --import repomd.xml.key

List:

$ rpm -q gpg-pubkey|sort

Getting info:

rpm -qi  | grep Summary   

(or without the ‘grep’ part to view full info of the key package)

To remove:

sudo rpm -e --allmatches 

Example:

[root chip ~]# rpm -q gpg-pubkey|sort
gpg-pubkey-1ac70ce6-41bebeef
gpg-pubkey-30c9ecf8-3f9da3f7
gpg-pubkey-4f2a6fd2-3f9d9d3b
gpg-pubkey-8df56d05-3e828977
gpg-pubkey-8df56d05-3e828977
gpg-pubkey-a109b1ec-3f6e28d5
gpg-pubkey-db42a60e-37ea5438
gpg-pubkey-e42d547b-3960bdf1
[root chip ~]# rpm -e --allmatches gpg-pubkey-8df56d05-3e828977
[root chip ~]# rpm -q gpg-pubkey|sort
gpg-pubkey-1ac70ce6-41bebeef
gpg-pubkey-30c9ecf8-3f9da3f7
gpg-pubkey-4f2a6fd2-3f9d9d3b
gpg-pubkey-a109b1ec-3f6e28d5
gpg-pubkey-db42a60e-37ea5438
gpg-pubkey-e42d547b-3960bdf1

1.2 Debian / Ubuntu

$ gpg --list-keys user_ID

Example:

$ gpg --list-keys
/home/iplsdk/.gnupg/pubring.gpg
-------------------------------
pub   2048R/E5****A4 2015-01-12
uid                  IBM Software Development Kit for Linux on Power
sub   2048R/F2*****9 2015-01-12

pub   4096R/78C*****4 2016-02-11
uid                  IBM SDK for Linux on Power (The IBM Software Development Kit for Linux on Power is a free Eclipse-based Integrated Development Environment) <iplsdk@linux.vnet.ibm.com>
sub   4096R/B3*****0 2016-02-1

Add a gpg-key in your environment:

After you get the .gpg file, you need to 'add-apt-key' it into your keyring. Here:
$ sudo apt-key add .gpg

Don’t forget:
$ sudo apt-get update

Cheers!

Installing vim on Fedora 25

UPDATE: This issue does not seem to happen in Fedora 26.

I just booted a fresh Fedora 25 (server, ppc64le) and attempted to install vim (I do not like vi) and had the following error:

Error: Transaction check error:
 file /usr/share/man/man1/vim.1.gz from install of 
vim-common-2:8.0.133-2.fc25.ppc64le conflicts with 
file from package vim-minimal-2:7.4.1989-2.fc25.ppc64le

Cool, let’s remove vim-minimal:

$ sudo dnf remove vim-minimal

If you see what I saw, this will trigger the uninstall of a whole lot of packages, including sudo.Saying it will remove sudo can scare the bejesus out of many people, but this will not be a problem if you are logged as root. (sudo -s / sudo -su).

$ sudo -su

Now you can bravely go on: remove vim-minimal and then install vim-enhanced. You should be all good.

Cheers!

IPython (& ipdb) issue with python 2.7

If you ever wanted to use ipdb (from IPython) debugger when using Python 2.7, you might have faced an issue like this:

$ sudo pip install ipython
Downloading/unpacking ipython
  Downloading ipython-6.0.0.tar.gz (5.1MB): 5.1MB downloaded
  Running setup.py (path:/tmp/pip_build_root/ipython/setup.py) egg_info for package ipython
    
    IPython 6.0+ does not support Python 2.6, 2.7, 3.0, 3.1, or 3.2.
    When using Python 2.7, please install IPython 5.x LTS Long Term Support version.
    Beginning with IPython 6.0, Python 3.3 and above is required.
...
Command python setup.py egg_info failed with error code 1 in /tmp/pip_build_root/ipython

So you gotta go ahead and install IPython==5.0, because it’s the last LTS version. Do:

#pip install IPython==5.0

And then you should get:

ImportError: No module named packaging.version

Hm, that was not expected. Installing setuptools or packaging did not work for me at this moment. To get away with this error I had to install pip3 and then upgrade pip:

  251  sudo apt-get install python3-pip
  252  sudo pip3 install --upgrade pip
  253  sudo pip install ipython==5.0
  254  sudo pip install ipdb

After that, both IPython and ipdb installed with no issues or errors and life was happy again.

ALTERNATIVE SOLUTION:

If the above still does not fix the issue, or if pip and ipython are bound to python 3, you can try this, according described in the packaging.python.org website:

  1. Download get-pip.py
  2. Run python get-pip.py. [2] This will install or upgrade pip. Additionally, it will install setuptools and wheel if they’re not installed already.

Let me know if that worked for you too.

Good Luck!