Monday, July 31, 2017

Get notification at specific time

Run below command in your terminal :

echo ' notify-send "Meeting with Munusamy in 5 minutes" ' | at 1:25PM

echo 'notify-send "Get your tea!"' | at now + 3 minutes

echo 'notify-send "Meeting in 1 hour with the big boss!"' | at 1pm tomorrow 

Commands used:
notify-send [OPTION...] <SUMMARY> [BODY] - create a notification

at and batch read commands from standard  input  or  a  specified  file
       which are to be executed at a later time, using /bin/sh.


Thursday, July 27, 2017

full screen mode in gvim editor

You need to set the following in your vimrc (mine is /etc/vimrc):

map <silent> <F11>
\    :call system("wmctrl -ir " . v:windowid . " -b toggle,fullscreen")<CR>

Also, you need to have this package installed:
sudo yum install wmctrl.x86_64 -y 

Friday, July 14, 2017

openshift - oc cluster up in specific address

When you do 'oc cluster up' , you can access openshift console using

But if you wish to specify IP address to access your openshift console make use of --public-hostname=<IP address>

This way you can access the  cluster even from outside (but within LAN ofcourse)

# oc cluster up --public-hostname=


Also, to retain configuration from previous run:

oc cluster up --host-data-dir=/mydata     --use-existing-config 

Where mydata is the directory created - ensure it has adequate permissions.


Also, you can ask for specific version like below:

oc cluster up  --public-hostname=   --version=v3.9 --service-catalog 


Another example (with all above combined):

oc cluster up \
--version=v3.9 \
 --service-catalog=true \ \ \
 --loglevel=2 \
 --host-data-dir=/mydata \

Where,  is your node's IP address.


Friday, July 7, 2017

Store and Run docker images locally & inspect contents of docker image


Store and Run docker images locally:

How to save image locally and use it:

// You have built an image named s3-store-build

// Now save locally
$ docker save s3-store-build > s3-store-build.tar

$ ls -ltrsh
261M -rw-rw-r--  s3-store-build.tar

// Load the image - ready to run:
$ docker load --input s3-store-build.tar


Inspecting contents of docker image:

# get your image name from this command

docker images

# here is the image name , save it to a tar file

docker save > s3.tar

mkdir test

cd test

# extract entire image using tar
tar xf ../s3.tar

# now extract individual tar files present
for filename in `find . -name  "*.tar" `; do tar xf  $filename; done

# Now, you check whether the file you are looking for is present in the image
find . -name <some_test_file_whether_present.txt>


Push image to docker hub:

How to push image to docker hub:

# docker login

// build a image using Dockerfile in PWD
# docker build -t   store-build .

# docker images | grep store-build

# docker tag <db548e132e30> saran/store-build

# docker push  saran/store-build  

Thursday, July 6, 2017

Pulling docker images using url

Pulling docker images:

Generally, you pull a public URL like:

docker pull gluster/gluster-centos

Sometimes you want to directly pull the Docker image using URL:

docker pull

The above can be any URL where Docker image present.