DEV Community: Janardhan Pulivarthi

How to rewrite history in git repo

Janardhan Pulivarthi — Sun, 16 Jul 2023 10:34:59 +0000

Changing the email address and author

ref: https://git-scm.com/book/en/v2/Git-Tools-Rewriting-History

/d/repo/go-training (main)
$ git filter-branch --commit-filter '
        if [ "$GIT_AUTHOR_EMAIL" = "person@example.com" ];
        then
                GIT_AUTHOR_NAME="New Person";
                GIT_AUTHOR_EMAIL="new.person@example.com";
                git commit-tree "$@";
        else
                git commit-tree "$@";
        fi' HEAD

Proceeding with filter-branch...

Rewrite 8430e1b897d5419fdasfsafasfsa685db2ae2327 (1/3) (0 seconds passed, remainRewrite 77c97ee4fsdafasfasdfaf5f9276348435fb768487e (2/3) (1 seconds passed, remainRewrite 6bb1508502ff0add7ae46d121a8d33a565f1889c (2/3) (1 seconds passed, remaining 0 predicted)
Ref 'refs/heads/main' was rewritten

short tutorial on git config

Janardhan Pulivarthi — Sun, 16 Jul 2023 05:00:01 +0000

Here is the starter config file.

you can open this with git config -e for any specific repository

[core]
    repositoryformatversion = 0
    filemode = false
    bare = false
        logallrefupdates = true
        symlinks = false
        ignorecase = true
[remote "origin"]
        url = https://github.com/j143/tcp
        fetch = +refs/heads/*:refs/remotes/origin/*
[branch "main"]
        remote = origin
        merge = refs/heads/main
[user]
        name = John Person
        email = jp@example.com
[credential "https://github"]
        com = j143
[credential]
        helper = store
[branch "show-tcp-syn-ack"]
    remote = origin
    merge = refs/heads/show-tcp-syn-ack

credential

these lines control which credential to use

[credential "https://github"]
        com = j143
[credential]
        helper = store

author

author details

[user]
        name = John Person
        email = jp@example.com

Remote repository for example GitHub

How to reference a git server

[remote "origin"]
        url = https://github.com/j143/tcp
        fetch = +refs/heads/*:refs/remotes/origin/*
[branch "main"]
        remote = origin
        merge = refs/heads/main

PVC stuck in terminating state?

Janardhan Pulivarthi — Mon, 14 Nov 2022 02:50:11 +0000

# kubectl get pvc
NAME                                  STATUS        VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
service-vol-0                          Terminating   pvc-1517f4d4-48ac-4892-9618-5bc3bfb255db   1Gi        RWO            sc     33d

Add the finalizer all null, in place of kubernetes.io/pv-protection to be able to delete.

kubectl patch pvc service-vol-0 -p '{"metadata":{"finalizers":null}}'

docs to know more about pv-protection: https://kubernetes.io/docs/concepts/storage/persistent-volumes/#storage-object-in-use-protection

Documentation links

Janardhan Pulivarthi — Tue, 02 Aug 2022 17:38:00 +0000

Basics

bash: https://www.gnu.org/software/bash/manual/bash.html#index-return
grub: https://www.gnu.org/software/grub/grub-documentation.html
wget: https://www.gnu.org/software/wget/manual/html_node/
git: https://git-scm.com/docs/git
java 8: https://docs.oracle.com/javase/8/docs/
gpg: https://www.gnupg.org/documentation/manuals/gnupg/
nano: https://www.nano-editor.org/dist/v2.0/nano.html
libstdc++: https://gcc.gnu.org/onlinedocs/libstdc++/faq.html#faq.what
dpkg: https://manpages.debian.org/bullseye/dpkg/dpkg.1.en.html
mvn cli: https://maven.apache.org/ref/3.8.1/maven-embedder/cli.html

Specs

gfm: - https://github.github.com/gfm/
yaml: - https://yaml.org/spec/1.2.2

Configure site specific search on Chrome

Janardhan Pulivarthi — Tue, 02 Aug 2022 17:37:49 +0000

If we want to search for music directly on spotify without google search.

Step 1

We would like to search the term nirvana in the search bar. And in the address bar the corresponding address is

open.spotify.com/search/nirvana

Step 2

Right click on the address bar, and select Edit search engines....

Step 3

Add configuration as shown

Step 4

Enter keyword spotify and press tab in the address bar.

What makes a good engineer?

Janardhan Pulivarthi — Tue, 02 Aug 2022 17:37:21 +0000

I am not sure, how good I am. But, here are some attributes that made me admire people.

1. Basics

Reads "Introduction to ...", and stays with academic rigor. Reads the documentation first, before searching for answer.

2. Time it takes

This person knows how much time does it take to write a program, review code. If the task is not well studied, at least try to pay attention to get the stat for how much time other people take.

3. Relentless focus

They have a focus with one goal in mind. Complete the task. They do not multitask.

4. Common-ness

They tend to have common appeal, generally approachable but not always.

5. Hand calculations

They know how to do a simple calculation for a complex program they are writing. So, they are sure of their momentum at any point.

6. They say "thank you"

They thank their manager, their direct reports and they are just thankful.

Not an exhaustive list.

What happens when a pod gets deleted

Janardhan Pulivarthi — Sun, 31 Jul 2022 11:06:14 +0000

1 State change and preparation

The pod is set to Terminating. And it will be isolated from end points

2 Run a preStop Hook

preStopHook will be executed. It is special command or http request sent to containers in the pod.

3 SIGTERM signal is sent to the pod

Kubernetes sends SIGTERM signal to all the containers in the pod. This lets them know that they are going to be terminated. SIGTERM can be handled, or ignored.

4 Kuberntes waits for the grace period

apiVersion: v1
kind: pod
metadata:
  name: app-pod
spec:
  containers:
  - name: app-container
    image: busybox
  terminationGracePeriodSeconds: 60

5 Kubernetes sends SIGKILL command

If the containers are still running it sends SIGKILL command. Kubernetes cleanup all the objects related to the terminated pod.\

How to check aws use all at once (to see hidden services)

Janardhan Pulivarthi — Sun, 31 Jul 2022 11:02:00 +0000

It is hard to know which service is consuming more or which service we forgot to turn off.

Billing by Services (Across all regions)

Go to https://console.aws.amazon.com/billing/home#/bills to see:

Pass Environmental variables along with Powershell commands

Janardhan Pulivarthi — Sat, 23 Jul 2022 05:01:06 +0000

PS1 > $env:NODE_OPTIONS="--openssl-legacy-provider" ; npm start

How does people know when you have opened an email?

Janardhan Pulivarthi — Sat, 18 Jun 2022 09:14:12 +0000

I think the image links are uniquely named so that when we open email, the image gets loaded from the link. This way the sender know that the email has been received.

Workaround: By default do not enable images for emails. Then you will be asked whether to display images or not from a sender.

What are some phrases you use that have magical powers ✨?

Janardhan Pulivarthi — Sun, 05 Jun 2022 08:27:06 +0000

For me, I always pass instructions in the form of questions. Like,

can you see why the code was not passing?,
can you help me at this step?, can you check the document once,
it might have some pointers?

Can you tell me to do something that I need to do every weekend to become better?

Janardhan Pulivarthi — Sun, 05 Jun 2022 08:23:14 +0000

On Weekends, I often tend to sleep, binge watch, or in the evening think deeply. Sometimes, I do manage to do something for 1 hour like contributing some code to open source etc.

Do you have any suggestions or anything that worked for you which us a better person?