Stranger's TechNotes

Run the below command: sudo chmod o+rw /var/run/docker.sock This will enable non privileged users to run all docker commands, 

Run: kubectl describe pod -n <namespace> <Pod name> | grep -A2 -B2 Reason For e.g.: kubectl describe pod -n myns my-pod-6d9bdcfbfc-k9jqw | grep -A2 -B2 Reason

Many a times we would like to view/manage the K8s cluster remotely using clients like Lens , k9s etc. I was searching for this information across, and found the below commands: # kubectl config view --flatten > k8s.cfg On the remote system, place the k8s.cfg file under: <user home dir>\.kube For e.g., on a Windows desktop for user abc, place it under: C:\Users\abc\.kube Note: You need to use this with caution as you can access complete K8s cluster with this data.

Docker on Windows is a boon to the developer community. Apart from the regular Linux based development I got a chance to use it today for something that I could not easily do directly on Windows (without a new third party software) I had to merge a number of PDFs to create a single PDF. Searching the Web gave me a number of options like online tools, ghostscript, pdftk etc. pdftk caught my attention as it was a perfect choice for my needs. But, I did not want to install it on my Windows desktop. I had docker desktop installed on my system. Hence I tried the following to achieve PDF merge: 1. Started a docker container with "ubuntu" image as follows: docker run --name ubuntu -d -it -v C:/temp:/var/mnt/pdf --entrypoint bash ubuntu -c tail -f /dev/null 2. Installed pdftk apt upgrade -y apt install pdftk -y 3. Executed pdftk to merge the pdfs. For e.g.: pdftk Aug2020.pdf Sep2020.pdf Oct2020.pdf Nov2020.pdf Dec2020.pdf Jan2021.pdf cat output  output.pdf 4. Now my merged pdf (out

Below is the code snippet that helps to get the number CPUs in C++11: ------------------------------------------------------------------------------------------------------- // Get the number of parallel threads possible. Just an hint to create number of threads unsigned int n = std::thread::hardware_concurrency(); std::cout << n << " concurrent threads are supported.\n"; -------------------------------------------------------------------------------------------------------

Recently, I was researching for opensource log management tools. I had only two requirements. Log Search and Log analytics. A lot of posts in the internet suggested me to use an ELK stack. But, I wanted to do something different. I found graylog as an alternative to ELK. One can setup and run it in minutes. It uses mongodb, elastic search and graylog server. Here is the login page: grylog provides different options to stream logs into graylog server. I used the simple UDP listener and forwarded logs from multiple devices into this listener. Next step is to create dashboards using the search. Here is the search page: Once search is done, you can add the widgets to a dashboard. The dashboard will help you to get the summary of your devices at one shot. It is also possible to generate alerts on different conditions. More here: https://www.graylog.org/