If you use NPM, install serve using npm install serve -g. Then run it using the command…

serve

If you have PHP install, use the command…

php -Slocalhost:8000

If python is your thing, use command…

python -m SimpleHTTPServer 8000

If you want to use Python3, use…

python3 -m http.server

You can exit for any of these using the keyboard shortuct Ctrl+C.

Source

npm run build -- --prefix-paths

This will pass the --prefix-pathsto the build script. Please note the double -- in the command.

Setup

Install scrcpy…

sudo apt-get install scrcpy

Connect your phone to your system using a USB cable. Make sure USB Debugging is enabled.

Run command…

adb tcpip 5555
adb connect <your android's ip address>:5555

Disconnect the USB Cable. Then run…

scrcpy

This should open a window where you can see the phone screen.

Usage

You’ll not have to do the USB connection again. Just run these commands to see the screen…

adb connect <your android's ip address>:5555
scrcpy

Keep in mind your phone IP might change. And phone reboot might end the adb tcpip 5555 demon. So that might have to be done again.

Source

const noteFile = this.app.workspace.getActiveFile(); // Get the currently Open Note
const metadata = this.app.metadataCache.getFileCache(noteFile);

import { MarkdownView } from 'obsidian';

// ...

// Access to the editor component...
const editor = this.app.workspace.getActiveViewOfType(MarkdownView)?.editor; 
const selectedText = editor.getSelection(); // Get selected text

You can also update selected text…

editor.replaceSelection("New Text Goes Here");

const noteFile = this.app.workspace.getActiveFile(); // Currently Open Note
if(!noteFile.name) return; // Nothing Open

// Read the currently open note file. We are reading it off the HDD - we are NOT accessing the editor to do this.
let text = await this.app.vault.read(noteFile); 

ALTER DATABASE <DATABASE_NAME> CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci ;
ALTER TABLE <table_name> CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
-- ALTER TABLE <table_name> MODIFY <field_name> TEXT CHARSET utf8mb4;

Source

If all went well, you’ll get the certificates automatically installed with in a minute or so.

Justed used this to get an certificate for Arathi M D.

Images

Images are the templates used to create Docker Containers. Container is a running instance of an image. Eg. ubuntu Image. Or Apache image.

Commands

Show all images available

docker images

Run the given image(ubuntu) in the interactive mode(-it)

docker run -it ubuntu

Get an image from repository

docker pull <image-name>[:<tag/version>]

Containers

Container is a running instance of an image.

Architechture

Host: The system where docker is run
Client: CLI interface to the docker daemon
Registry: Docker Hub or other places where images are stored.

Dockerfile

Dockerfile is a text file with insturctions to build an image. Generally, it has the filename Dockerfile. Sample…

# The base image. This search locally - if not present, it gets pulled from repository
FROM ubuntu

# Run this command
RUN apt-get update

Instructions

• FROM: Sets the Base Image for subsequent instructions.
• RUN: execute any commands in a new layer on top of the current image and commit the results.
• CMD: provide defaults for an executing container.
• EXPOSE: informs Docker that the container listens on the specified network ports at runtime. NOTE: does not actually make ports accessible.
• ENV: sets environment variable.
• COPY: copies new files or directories to container. By default this copies as root regardless of the USER/WORKDIR settings. Use –chown=USER:GROUP to give ownership to another user/group. (Same for ADD.)
• VOLUME: creates a mount point for externally mounted volumes or other containers.
• USER: sets the user name for following RUN / CMD / ENTRYPOINT commands.
• WORKDIR: sets the working directory.
• LABEL: apply key/value metadata to your images, containers, or daemons.

Dockerfile Cheetsheet
Dockerfile Reference

Run docker build . in the same folder to build an image from this Dockerfile.

Docker Compose

Its a tool for creating and running systems which has multiple containers within it. Eg. A web app will require an API Server, Frontend Server and Database Server. You can run all this together using docker compose.

You’ll have to install docker-compose before you use it – its NOT part of the default docker install in linux.

Use docker-compose.yml to design the system.

Commands

docker-compose config   # Checks validity of the docker-compose.yml file
docker-compose up       # Start all Services. Add -d flag to run in the background.
docker-compose down     # Stop all Services

Volumes

Think of Volumes as the ‘HardDisks’ for the containers – the persintent data storage location. Containers can read and write to it – and the data will stay even after the containers are shut down.

Uses

• Decouple data storage from containers
• Share data accross multiple containers
• Persistant storage – when stoping the container, the data doesn’t get deleted.

Commands

docker volume create NAME
docker volume ls
docker volume install NAME # Show details about the volume.
docker volume rm NAME # Remove volume
docker run -v NAME:/var/lib/www IMAGE_NAME # Attaching a volume to an IMAGE - and mount it at location /var/lib/www

Bind Mounts

An alternative to using volumes is bind mount. Bind mount is a location in the host system that is running the container. This can be changed by the host system/user(unlike volumes).

Debugging

Comnand to run an interactive shell with in a container…

docker exec -it NAME sh

Source

Run these commands on your ubuntu system to install Docker.

sudo apt update
sudo apt install apt-transport-https ca-certificates curl software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu focal stable"
sudo apt update
sudo apt install docker-ce

Check the instalation using this command…

sudo systemctl status docker

Getting docker to run without the root user, add your username to the docker group…

sudo usermod -aG docker ${USER}

To apply the new group membership, log out of the server and back in.

Test Docker

docker run hello-world

Basic Commands

See all images

docker images

See all containers

docker containers

Running containers

docker ps

Others…

docker info
docker images
docker pull
docker run
docker start
docker stop
docker stats
docker system df
docker system prune

Install docker-compose

Source

sudo curl -L "https://github.com/docker/compose/releases/download/1.28.2/docker-compose-(uname -s)-(uname -m)" -o /usr/local/bin/docker-compose
sudo chmod +x /usr/local/bin/docker-compose
docker-compose --version # Test

Configure Docker

Source

We have to change the data directory from / to somewhere with more space – it will easily run into GBs.

Stop docker using command…

sudo systemctl stop docker

Edit /etc/docker/daemon.json (if it doesn’t exist, create it) and include:

{
  "data-root": "/new/path/to/docker-data"
}

Copy existing docker data to the new location…

sudo rsync -axPS /var/lib/docker/ /new/path/to/docker-data

Restart Docker and check…

sudo systemctl start docker
docker info | grep 'Docker Root Dir'
docker ps