QEMU: Installation of QEMU VMs on Mac OS

Credit Goes to : Gist GitHub

Install QEMU on OSX

QEMU requires brew in OSX, so we need to install brew first.

Installing Brew

To install brew we need to have the developer tools enabled in our system. In order to install those tools, we have two options.

1. Download Xcode form the AppStore
2. In your terminal run the following command: xcode-select --install

Once you have the developer tools, run the following command in your terminal to install brew:

$ ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Once the installation is finished, we can test the brew installation in our terminal with the command

$ brew doctor

Installing QEMU

Now that we have brew on the system we can proceed to the QEMU installation. To do that we use a simple command:

$ brew install qemu

When the installation is finished, we can run the following command to test if the installation was successful:

$ qemu-system-x86_64 --version

Installing Ubuntu on QEMU

We need to follow a series of steps in order to install an Ubuntu VM on QEMU. The first one is go to the Ubuntu website and download an .iso file of the operating system.
Once we have the .iso, we need to to this:

1. Create a folder in your computer (with any name and anywhere). $ mkdir ubuntu_vm
2. Move the .iso file in the folder that you just create. $ mv ubuntu.iso ./your-folder
3. Then move inside the folder you just create $ cd ubuntu_vm
4. Inside the folder, create the drive file of the system qemu-img create -f qcow2 ubuntu_drive.qcow2 10G
5. Run ls to verify that the .iso and the qcow file are inside the folder

Once you have the previous steps, you can run the following command to run the iso and complete the installation:

• -show-cursor option didnt worked for me in the mac
• -enable-kvm Mac OS is BSD based, so it wont have Linux Kernel where KVM supported.

So please remove them on Mac before using.

qemu-system-x86_64 \
  -m 2048 \
  -vga virtio \
  -show-cursor \
  -usb \
  -device usb-tablet \
  -enable-kvm \
  -cdrom your_ubuntu.iso
  -drive file=ubuntu_drive.qcow2,if=virtio \
  -accel hvf \
  -cpu host

The previous command, will run the iso, when you are there, you need to complete the ubuntu installation, so once you see something you must:

1. Click on Install Ubuntu
2. Select erase disk when the installer ask about it
3. When the installer asks you to restart the machine close the QEMU window.

Now, in order to make more easy to run our QEMU VM, we are going to create a shell command. So, lets do the following.

First, create a new file in any place you want:

$ vi ubuntuvm.sh

Then, paste the following and adept it to your needs:

qemu-system-x86_64 \
  -m 2048 \
  -vga virtio \
  -show-cursor \
  -usb \
  -device usb-tablet \
  -enable-kvm \
  -cdrom your_ubuntu.iso
  -drive file=~/absolute/path/to/your/ubuntu_drive.qcow2,if=virtio \
  -accel hvf \
  -cpu host

And finally, write and quit.

As you can see, the command deletes the instruction about the .iso file. This is because now we have the operating system already installed.
Now in order to run the vm, we need to make our file executable. So run the following command:

$ chmod +x ubuntuvm.sh

And finally to run it:

$ ./ubuntuvm

And that is it. We should see our virtual machine running correctly.

Python FastAPI: Notes

My FastAPI notes.

Installation

pip install "fastapi[all]"

Basic App: Assume filename main.py

from typing import Optional
from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def read_root():
    return {"Hello": "World"}

@app.get("/items/{item_id}")
def read_item(item_id: int, q: Optional[str] = None):
    return {"item_id": item_id, "q": q}

To start the API service

uvicorn main:app --reload

• To access API Documentation, http://ip.port/docs

How to resolve InitializeSandbox() called with multiple threads in process gpu-process. Error in Linux with Google Chrome ?

Hello Everyone,

While launching google chrome browser, if you are getting below error in Linux, remove Google Chrome config directory from your home folder.

❯❯ ~  18:03 google-chrome-stable   
[45359:45359:0125/180542.953317:ERROR:sandbox_linux.cc(378)] InitializeSandbox() called with multiple threads in process gpu-process.

Note: Doing below command will delete your chrome data, hope you have enabled cloud sync.
So remove config directory of google chrome from your home directory

❯❯ ~   18:07 rm -rf ~/.config/google-chrome

Then launch google chrome again
Hope it helps.

---

Thanks
Raaz

NodeJS: Important NodeJS Modules and URLs

This post is a on going article of important NodeJS Modules with thier usage.

Linux: How to validate /etc/fstab post changes ?

If You have done any changes to `/etc/fstab` file, and would like to check for any errors, then you can use the command `sudo findmnt --verify`.

Linux: How to generate self-signed certificate in Linux using openssl ?

Make sure openssl installed in your server/machine

Process includes 3 steps as below

• {{ step.description }}
  

  {{ step.command }}

---

Execution and output

                    ❯❯ cert  23:03 openssl genrsa -out ca.key 2048
                    Generating RSA private key, 2048 bit long modulus (2 primes)
                    ............+++++
                    ...........................+++++
                    e is 65537 (0x010001)
                    ❯❯ cert  23:03 openssl req -new -key ca.key -subj "/CN=THELINUXNMEN-BLOG-CA" -out ca.csr
                    ❯❯ cert  23:03 ls
                    ca.csr  ca.key
                    ❯❯ cert  23:03 openssl x509 -req -in ca.csr -signkey ca.key -out ca.crt
                    Signature ok
                    subject=CN = THELINUXNMEN-BLOG-CA
                    Getting Private key
                    ❯❯ cert  23:04 ls
                    ca.crt  ca.csr  ca.key
                    ❯❯ cert  23:04