Useful Commands

Docker

Code	Description
docker rm $(docker ps -a -q -f status=exited)	To remove all the containers that have exited
EC2_REGION=wget -q -O - http://169.254.169.254/latest/meta-data/placement/availability-zone|sed s/.$// aws ecr get-login --region $EC2_REGION --no-include-email	To login into ECR
docker pull amazon/amazon-ecs-sample	Just a ecs sample

VS Code Shortcut

Shortcut	Description
shift + opt + down arrow key	Duplicate current line
cmd + k + 0	fold all region
cmd + k + j	unfold all region
cmd + opt + [	fold single region
cmd + opt + ]	unfold fold single region
cmd + K + D	compare with saved

Python

Description	Code	Remarks
Create a virtual environment called venv	virtualenv venv
Activate the virtual environment	. venv/bin/activate
See installed	pip freeze
Create a requirements file	pip freeze > requirements.txt
Deactivate the virtual environement	deactivate
Remove the virtual environment	rm -r venv
To load pip file	pip install -r requirements.txt
Jupyter notebook kernel	within the virtual env python -m ipykernel install --user --name=<kernel name>	YT Vid

Git CLI

Reference: https://marklodato.github.io/visual-git-guide/index-en.html

Description	Code
View local commits	git log origin/main..HEAD
View git commits in graph	git log --oneline --graph --decorate
Undo 1 commit on current branch	git reset --soft HEAD~1
Merge main into current branch	git checkout <branch>, git merge main

EC2 Configuration

Description	Code
To know details about your virtual instances	curl http://<instance number>/latest/meta-data/
To know details about virtual instance user permission	curl http://<instance number>/latest/meta-data/iam/security-credentials/MyAdmin
To know what is your user name in your policy, you can use variable	"Resource": ["arn:aws:s3:::mybucket/${aws:username}/*"]

BASH CLI

Description	Code
History	Ctrl R
Next History	Ctrl R
Cut	Ctrl U
Paste	Ctrl Y

VIM commands

Description	Code
Set number	:set number
Go to line	:[linenumber]
Go to end of line	$
Undo	Ctrl U
Indent next 3 lines	3>>
Unindent next 3 lines	3<<
Delete inside word	diw
Delete word to end of line	dw
Enter a new line and go into insert mode	o

Script Commands

Description	Code	Remarks
Check if file exist	test -f test.py; echo $?	-f flag checks if file exists. If returns 0 = true

Network troubleshooting

Description	Code	Remarks
Check tcp traffic	tcpdump dst port 443	dump traffic on port 443, result format = (incoming traffic) > (outgoing traffic)

S3 Copy Commands

Description	Code	Remarks
S3 copy local folder to bucket	aws s3 cp ./scripts s3://<bucket-name>/scripts --recursive	copy from local script folder, into s3 bucket with prefix scripts

Python manipulation

Description	Code	Remarks
From list to dict	def Convert(lst): res_dct = {lst[i]: lst[i + 1] for i in range(0, len(lst), 2)} return res_dct lst = ['a', 1, 'b', 2, 'c', 3] print(Convert(lst))	https://www.geeksforgeeks.org/python-convert-a-list-to-dictionary/
From dict retrieve elements for array	subnets = [{subnet['SubnetId'] for subnet in resp}]
From dict retrieve single element as key	subnets = [{subnet['SubnetId']:subnet for subnet in resp}]
Create a new-dict with desired key e.g. k = [key_a,key_b] from dict	newdict = {k: testdict[k] for k in keep}	https://stackoverflow.com/questions/32727294/remove-keys-from-object-not-in-a-list-in-python

Create Windows Program Bin and add environment path

Description	Code	Remarks
From powershell create directory	New-Item -Path "$env:UserProfile\bin" -ItemType Directory
Add folder to path bin	reg add HKEY_CURRENT_USER\Environment /v Path /t REG_EXPAND_SZ /d "$env:Path;$env:UserProfile\bin"
Check path is added	$env:Path

Check OS Version

Description	Code	Remarks
Windows	systeminfo
Linux	cat /etc/os-release
Mac	system_profiler SPSoftwareDataType