sudo su as

Type 1:

cat ScriptFile
whoami
sudo su - user2 <<EOF
whoami
EOF


$ ssh user1@RemoteHost 'bash -s' < ScriptFile 

Output:
user1
user2
Stderr: Pseudo-terminal will not be allocated because stdin is not a terminal.



using pssh:
[ in this approach: (-l)  no need to copy file to remote host to run the command. ]

$ pssh -i -H RemoteHost -l user1 -o OutPutDir -I 'bash -s'< ScriptFile 

[1] 19:28:14 [SUCCESS] RemoteHost
user1
user2

$ pssh -i -H RemoteHost -l user1 -o OutPutDir -I < ScriptFile 

Output:
[1] 19:27:30 [SUCCESS] RemoteHost
user1
user2
Stderr: Pseudo-terminal will not be allocated because stdin is not a terminal.


NOTE: [ quick pssh help]

-h HOST_FILE, --hosts=HOST_FILE

-H HOST_STRING, --host=HOST_STRING

-l USER, --user=USER  username (OPTIONAL) [ small l ]

-p PAR, --par=PAR     max number of parallel threads (OPTIONAL)

-o OUTDIR, --outdir=OUTDIR

-i, --inline          inline aggregated output and error for each server

-I, --send-input      read from standard input and send as input to ssh [ caps i ]

pssh -i -h hosts.txt -l user1 o OutputDir -I 'bash -s' < ScriptFile

pssh -h hosts.txt -l irb2 -o /tmp/foo uptime

perl html5 video page gen code

#!/usr/bin/env perl

print ("<!DOCTYPE html>\n");
print ("<html>\n");
print ("<body>\n");

my @files = `ls *.mp4`;

foreach $a (@files) {
    print ("<video width=\"320\" height=\"240\" controls>\n");
    print ("<source src=\"$a\" type=\"video/mp4\">\n");
    print ("</video>\n");
}

print ("</body>\n");
print ("</html>\n");

php image gallery

Steps:

1. create your main folder. [example pictures ]  [ mkdir pictures]
2. create another folder as images under pictures [ mkdir pictures/images ] [ NOTE: In the following code the subfolder name it expect as images ]
3. copy the following code to pictures folder, as filename index.php
4. copy all your images to pictures/images

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />

<title>Gallery from Folder Demo</title>

<style type="text/css">

<!--

li{

list-style-type:none;

margin-right:10px;

margin-bottom:10px;

float:left;

}

-->

</style></head>

<body>

<ul>

<?php

$dirname = "images/";

$images = scandir($dirname);

shuffle($images);

$ignore = array(".", "..");

foreach($images as $curimg){

if(!in_array($curimg, $ignore)) {

echo "<li><a href=\"$dirname$curimg\"><img src=\"$dirname$curimg\" height=200 width=200 /></a></li>\n ";

}

}

?>

</ul>

</body>

</html>

### compress image ###

Along with the above you also might need to compress the file.

at ubuntu, you can use "convert" command to compress the image.

NOTE: the smaller the percentage the smaller is the file.

convert source.jpg -resize 20% destination.jpg

A 4MB file 20% came around 350KB file.

tmux

Quick tmux commands:

NOTE: [ consider all following key is after the combination (ctrl-b) [ In standard configuration ]

split tmux vertically     : %
split tmux horizontally : "

Moving between panes:
Move Left                     : left arrow or {
Move Right                   : right arrow or }
Move Up                       : up arrow
Move Down                  : down arrow
next pane                       : o
show number of each panes and move: b q + number


Resizing panes

You may want to resize panes to fit your need. Here’s a list how to do that :

(Ctrl-b) + : then type resize-pane -D (Resizes the current pane down)
(Ctrl-b) + : then type resize-pane -U (Resizes the current pane upward)
(Ctrl-b) + : then type resize-pane -L (Resizes the current pane left)
(Ctrl-b) + : then type resize-pane -R (Resizes the current pane right)
(Ctrl-b) + : then type resize-pane -D 5 (Resizes the current pane down by 5 cells)
(Ctrl-b) + : then type resize-pane -U 5 (Resizes the current pane upward by 5 cells)
(Ctrl-b) + : then type resize-pane -L 5 (Resizes the current pane left by 5 cells)
(Ctrl-b) + : then type resize-pane -R 5 (Resizes the current pane right by 5 cells)
(Ctrl-b) + : then type resize-pane -t 2 5 (Resizes the pane with the id of 2 down by 5 cells)
(Ctrl-b) + : then type resize-pane -t -L 5 (Resizes the pane with the id of 2 left by 5 cells)

press (Ctrl-b) + : resize-pane -D 13 to make it down for 13 cells.


create more window: ctrl-b c

(Ctrl-b) + n : Move to next window
(Ctrl-b) + p : Move to previous window
(Ctrl-b) + w : Interactively choose the window (useful if you have more than 2 window)


Detached: ctrl-b d

Listing the tmux session: tmux ls

attaching the tmux session: tmux attach -t <session-name>

### sync tmux panes ###

Ctrl-B :
setw synchronize-panes on
clear history

su as another user

sudo su - poweruser << EOF
whoami
EOF

Interesting motd with figlet or toilet

What if you want to have interesting motd?

You can do these interesting motd using figlet.

Example:

You Just need to install [ toilet ] and try these interesting output.

sudo apt-get install toilet

ansible-playbook for docker cassandra cluster.

The following command will create a cassdb cluster using ansible.
#####
---
- hosts: all
  tasks:
  - name: coping the file to all the docker server
    template: src=cassandra.yaml.j2 dest=/tmp/cassandra.yaml
  - name: running some command
    raw: sudo docker run -i -t -d --name cassdb --net host -v /cassdata:/var/lib/cassandra cassdb /bin/bash; containerID=`sudo docker inspect -f '{{.Id}}' cassdb`; sudo cp /tmp/cassandra.yaml /var/lib/docker/aufs/mnt/$containerID/etc/cassandra/cassandra.yaml; sudo docker exec cassdb rm -rf /var/lib/cassandra/*; sudo docker exec cassdb /etc/init.d/cassandra start



#####
command would be:

ansible-playbook  docker-inventory_hosts install_cassandra_playbook.yml



########

NOTE: Following is the variable that I have added in the "cassandra.yaml.j2" file, that need to be interpolated, dynamically.

cluster_name: {{ cluster_name }}
          - seeds: {{ hostvars[groups['docker-akamai'][0]]['ansible_eth0']['ipv4']['address'] }}
listen_address: {{ ansible_default_ipv4.address }}
broadcast_rpc_address: {{ ansible_default_ipv4.address }}


### my cassdb docker image:

docker pull amitmund/cassdb:latest

#######

$ sudo docker exec cassdb nodetool status
Note: Ownership information does not include topology; for complete information, specify a keyspace
Datacenter: BLR
===============
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address        Load       Tokens  Owns    Host ID                               Rack
UN  192.168.1.10  54.93 KB   256     37.4%   e7915e97-babf-49fd-bcdf-4434b4443fba  R1
UN  192.168.1.11  261.03 KB  256     32.7%   a0589928-f5eb-496f-8456-5018fabb75ca  R1
UN  192.168.1.12  169.35 KB  256     29.9%   219d1439-fd0d-4ea9-ae03-4d25fe0334fc  R1