351 lines
16 KiB
Markdown
351 lines
16 KiB
Markdown
# Essential Linux
|
|
|
|
## Introduction to Linux
|
|
|
|
### Where does Linux originate from?
|
|
|
|
* The spiritual mother of Linux is [Unix](https://en.wikipedia.org/wiki/Unix).
|
|
* [POSIX](https://en.wikipedia.org/wiki/POSIX) is not an OS in itself but a **standard**.
|
|
* Which OS's are [POSIX compliant](https://en.wikipedia.org/wiki/POSIX#POSIX-oriented_operating_systems)
|
|
|
|
### Who is behind this project?
|
|
|
|
* Who is [Richard Stallmann](https://en.wikipedia.org/wiki/Richard_Stallman)?
|
|
* Who is [Linux Torvalds](https://en.wikipedia.org/wiki/Linus_Torvalds)?
|
|
|
|
### What is the deal with 'GNU-slash-Linux'?
|
|
|
|
* [GNU/Linux](https://en.wikipedia.org/wiki/GNU/Linux_naming_controversy) controversy
|
|
* What is a [kernel](https://en.wikipedia.org/wiki/Kernel_(operating_system))
|
|
* What does [GNU](https://www.gnu.org/software/) bring to the table?
|
|
* What's the deal with [userspace and kernelspace](https://unix.stackexchange.com/questions/137820/whats-the-difference-of-the-userland-vs-the-kernel)?
|
|
* [userspace](http://www.linfo.org/user_space.html)
|
|
* [kernelspace](http://www.linfo.org/kernel_space.html)
|
|
|
|
|
|
|
|
### Where can you *get* some Linux?
|
|
|
|
* You probably already have a Linux computer running at [home](https://opensource.com/article/19/8/everyday-tech-runs-linux)!
|
|
|
|
|
|
|
|
### Debian
|
|
|
|
* [Reasons](https://www.debian.org/intro/why_debian) to choose Debian.
|
|
* Why is Debian called [the universal operating system](https://www.reddit.com/r/debian/comments/22j0wf/so_why_debian_is_called_the_universal_operating/)?
|
|
* [comparison](https://en.wikipedia.org/wiki/Comparison_of_instruction_set_architectures) of CPU architectures
|
|
* [download](https://www.debian.org/distrib/netinst) Debian
|
|
|
|
## How to create a virtual machine
|
|
|
|
Step by step walk-through of a VM creation in virtualbox with some notes on each step with best practice pointers.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
## Breakdown of the Debian installation
|
|
|
|
All right, enough talking, let's get started!
|
|
I'll install a full blown and modern graphical Debian machine and I would like you to **not** do it yourself but take **notes** on each step so you'll be able to reference your notes later **when** I ask you to install a machine yourself.
|
|
|
|
* [step by step](https://debian-handbook.info/browse/stable/sect.installation-steps.html) installation instructions
|
|
* **don't set a root password, use `sudo` instead**
|
|
* **stress the graphical/minimal difference**
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
### Exercise
|
|
|
|
OK, now it's up to you!
|
|
Please install a Debian machine with the default graphical environment.
|
|
Once installed, take some time out to explore the system.
|
|
Which software is installed by default?
|
|
How can you tweak the system settings such as language, keyboard, networking?
|
|
Can you install extra software?
|
|
|
|
## Quick look at an idle system
|
|
|
|
|
|
|
|
|
|
|
|
## Package managers
|
|
|
|
* what is a [package manager](https://en.wikipedia.org/wiki/Package_manager)
|
|
|
|
### Graphical installation
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
### Command line installation
|
|
|
|
```bash
|
|
waldek@hellodebian:~$ htop
|
|
-bash: htop: command not found
|
|
waldek@hellodebian:~$ apt install htop
|
|
E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied)
|
|
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?
|
|
waldek@hellodebian:~$ sudo apt install htop
|
|
[sudo] password for waldek:
|
|
Reading package lists... Done
|
|
Building dependency tree... Done
|
|
Reading state information... Done
|
|
Suggested packages:
|
|
lm-sensors strace
|
|
The following NEW packages will be installed:
|
|
htop
|
|
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
|
|
Need to get 127 kB of archives.
|
|
After this operation, 328 kB of additional disk space will be used.
|
|
Get:1 http://deb.debian.org/debian bullseye/main amd64 htop amd64 3.0.5-7 [127 kB]
|
|
Fetched 127 kB in 0s (2,030 kB/s)
|
|
Selecting previously unselected package htop.
|
|
(Reading database ... 141359 files and directories currently installed.)
|
|
Preparing to unpack .../htop_3.0.5-7_amd64.deb ...
|
|
Unpacking htop (3.0.5-7) ...
|
|
Setting up htop (3.0.5-7) ...
|
|
Processing triggers for mailcap (3.69) ...
|
|
Processing triggers for desktop-file-utils (0.26-1) ...
|
|
Processing triggers for hicolor-icon-theme (0.17-2) ...
|
|
Processing triggers for gnome-menus (3.36.0-1) ...
|
|
Processing triggers for man-db (2.9.4-2) ...
|
|
waldek@hellodebian:~$
|
|
```
|
|
|
|
|
|
|
|
|
|
The *menu bar* at the bottom shows you can press **F10** to quit.
|
|
This does not work because of a shortcut of gnome-terminal!
|
|
You can deactivate this shortcut in the preferences though.
|
|
But pressing **q** also exits the program.
|
|
|
|
|
|
|
|
### Adding a secondary desktop environment
|
|
|
|
During the initial installation we where offered a choice of desktop environments to install.
|
|
This menu was an actual program called `tasksel` we can run again to add different ones!
|
|
As it's a program that can heavily modify the system, we need administrator privileges.
|
|
|
|
```bash
|
|
waldek@hellodebian:~$ sudo tasksel
|
|
[sudo] password for waldek:
|
|
```
|
|
|
|
|
|
|
|
|
|
|
|
|
|
## Changing the runlevel
|
|
|
|
The **first** process started by the kernel can be discover by `htop` and is `/usr/sbin/init`.
|
|
This is rather vague but we can find out a *bit* more about this program via `ls` which we'll get into more detail later.
|
|
For now just have a look at the output of the following commmand.
|
|
|
|
```bash
|
|
waldek@hellodebian:~$ ls -l /usr/sbin/init
|
|
lrwxrwxrwx 1 root root 20 Jul 13 2021 /usr/sbin/init -> /lib/systemd/systemd
|
|
waldek@hellodebian:~$
|
|
```
|
|
|
|
Now, what *is* this [systemd](https://en.wikipedia.org/wiki/Systemd)?
|
|
And more importantly, *how* do we interact with it?
|
|
For now just accept that the main program to communicate with `systemd` is `systemctl`.
|
|
A quick look at the `man` pages gives us the following.
|
|
|
|
```bash
|
|
SYSTEMCTL(1) systemctl SYSTEMCTL(1)
|
|
|
|
NAME
|
|
systemctl - Control the systemd system and service manager
|
|
|
|
SYNOPSIS
|
|
systemctl [OPTIONS...] COMMAND [UNIT...]
|
|
|
|
DESCRIPTION
|
|
systemctl may be used to introspect and control the state of the "systemd" system and service manager. Please refer to systemd(1) for an
|
|
introduction into the basic concepts and functionality this tool manages.
|
|
|
|
```
|
|
|
|
```bash
|
|
waldek@hellodebian:~$ sudo systemctl set-default multi-user.target
|
|
[sudo] password for waldek:
|
|
Removed /etc/systemd/system/default.target.
|
|
Created symlink /etc/systemd/system/default.target → /lib/systemd/system/multi-user.target.
|
|
waldek@hellodebian:~$ sudo reboot now
|
|
```
|
|
|
|
After the reboot you'll be confronted with the following screen.
|
|
Don't stress, your machine is not broken!
|
|
It's just running in a more *minimal* mode.
|
|
You can log in just as with the graphical login window but you'll only have a command line to interact with the machine.
|
|
A quick look at `htop` tells us not a lot of stuff is running, just the bare minimum.
|
|
|
|
|
|
|
|
|
|
To *undo* this change and regain the graphical interface again you can run the following commands.
|
|
|
|
```bash
|
|
waldek@hellodebian:~$ sudo systemctl set-default graphical.target
|
|
[sudo] password for waldek:
|
|
Removed /etc/systemd/system/default.target.
|
|
Created symlink /etc/systemd/system/default.target → /lib/systemd/system/graphical.target.
|
|
waldek@hellodebian:~$ sudo reboot now
|
|
```
|
|
|
|
## Exercise
|
|
|
|
Please create a second virtual machine and install a **minimal** Debian.
|
|
Minimal means **no graphical environment**.
|
|
I advise you to **not** set a root password.
|
|
Once this machine is up and running, install a few programs.
|
|
The only one we saw up until now is `htop` but maybe try out `bmon`, `elinks` and/or `ranger`.
|
|
|
|
## Guest additions
|
|
|
|
Let's make our user experience a bit nicer.
|
|
Virtual machines can *integrate* with the host machine more fluently when you install the guest additions in the VM.
|
|
It's a three step process.
|
|
|
|
1. install the required packages to build the guest additions in you VM
|
|
1. insert the guest additions CD into your VM
|
|
1. run the correct script from the CD
|
|
|
|
The dependencies can be installed as follows.
|
|
First you `update` your package list, next you install three packages.
|
|
|
|
* `build-essential`
|
|
* `dkms`
|
|
* `linux-headers-$(uname -r)`
|
|
|
|
The *third* package name is a bit weird looking no?
|
|
This is a bit of command line kung fu.
|
|
The actual *name* of the package is as follows.
|
|
|
|
```
|
|
waldek@hellodebian:~$ echo linux-headers-$(uname -r)
|
|
linux-headers-5.10.0-11-amd64
|
|
waldek@hellodebian:~$
|
|
```
|
|
|
|
The `$(uname -r)` is a call to a program called `uname` with the option `-r`.
|
|
We'll go more into detail on this later.
|
|
|
|
```
|
|
waldek@hellodebian:~$ sudo apt update
|
|
Hit:1 http://deb.debian.org/debian bullseye InRelease
|
|
Hit:2 http://deb.debian.org/debian bullseye-updates InRelease
|
|
Hit:3 http://security.debian.org/debian-security bullseye-security InRelease
|
|
Reading package lists... Done
|
|
Building dependency tree... Done
|
|
Reading state information... Done
|
|
All packages are up to date.
|
|
waldek@hellodebian:~$ sudo apt install build-essential dkms linux-headers-$(uname -r)
|
|
Reading package lists... Done
|
|
Building dependency tree... Done
|
|
Reading state information... Done
|
|
The following additional packages will be installed:
|
|
binutils binutils-common binutils-x86-64-linux-gnu dctrl-tools dpkg-dev fakeroot g++ g++-10 gcc gcc-10 libalgorithm-diff-perl
|
|
libalgorithm-diff-xs-perl libalgorithm-merge-perl libasan6 libatomic1 libbinutils libc-dev-bin libc-devtools libc6-dev libcc1-0 libcrypt-dev
|
|
libctf-nobfd0 libctf0 libfakeroot libgcc-10-dev libitm1 liblsan0 libnsl-dev libstdc++-10-dev libtirpc-dev libtsan0 libubsan1
|
|
linux-compiler-gcc-10-x86 linux-headers-5.10.0-11-common linux-headers-amd64 linux-kbuild-5.10 linux-libc-dev make manpages-dev patch
|
|
Suggested packages:
|
|
binutils-doc debtags debian-keyring g++-multilib g++-10-multilib gcc-10-doc gcc-multilib autoconf automake libtool flex bison gdb gcc-doc
|
|
gcc-10-multilib gcc-10-locales glibc-doc libstdc++-10-doc make-doc ed diffutils-doc
|
|
The following NEW packages will be installed:
|
|
binutils binutils-common binutils-x86-64-linux-gnu build-essential dctrl-tools dkms dpkg-dev fakeroot g++ g++-10 gcc gcc-10 libalgorithm-diff-perl
|
|
libalgorithm-diff-xs-perl libalgorithm-merge-perl libasan6 libatomic1 libbinutils libc-dev-bin libc-devtools libc6-dev libcc1-0 libcrypt-dev
|
|
libctf-nobfd0 libctf0 libfakeroot libgcc-10-dev libitm1 liblsan0 libnsl-dev libstdc++-10-dev libtirpc-dev libtsan0 libubsan1
|
|
linux-compiler-gcc-10-x86 linux-headers-5.10.0-11-amd64 linux-headers-5.10.0-11-common linux-headers-amd64 linux-kbuild-5.10 linux-libc-dev make
|
|
manpages-dev patch
|
|
0 upgraded, 43 newly installed, 0 to remove and 0 not upgraded.
|
|
Need to get 62.0 MB of archives.
|
|
After this operation, 258 MB of additional disk space will be used.
|
|
Do you want to continue? [Y/n] y
|
|
```
|
|
|
|
Once this is done we can **insert** the CD.
|
|
You can verify the disk's content via the files explorer in gnome.
|
|
|
|
|
|
|
|
Now, open a terminal and run the following.
|
|
|
|
```
|
|
waldek@hellodebian:/media/cdrom0$ cd /media/cdrom0/
|
|
waldek@hellodebian:/media/cdrom0$ ls
|
|
AUTORUN.INF NT3x TRANS.TBL VBoxLinuxAdditions.run VBoxWindowsAdditions.exe
|
|
autorun.sh OS2 VBoxDarwinAdditions.pkg VBoxSolarisAdditions.pkg VBoxWindowsAdditions-x86.exe
|
|
cert runasroot.sh VBoxDarwinAdditionsUninstall.tool VBoxWindowsAdditions-amd64.exe
|
|
waldek@hellodebian:/media/cdrom0$ sudo bash VBoxLinuxAdditions.run
|
|
Verifying archive integrity... All good.
|
|
Uncompressing VirtualBox 6.1.28 Guest Additions for Linux........
|
|
VirtualBox Guest Additions installer
|
|
Copying additional installer modules ...
|
|
Installing additional modules ...
|
|
VirtualBox Guest Additions: Starting.
|
|
VirtualBox Guest Additions: Building the VirtualBox Guest Additions kernel
|
|
modules. This may take a while.
|
|
VirtualBox Guest Additions: To build modules for other installed kernels, run
|
|
VirtualBox Guest Additions: /sbin/rcvboxadd quicksetup <version>
|
|
VirtualBox Guest Additions: or
|
|
VirtualBox Guest Additions: /sbin/rcvboxadd quicksetup all
|
|
VirtualBox Guest Additions: Building the modules for kernel 5.10.0-11-amd64.
|
|
update-initramfs: Generating /boot/initrd.img-5.10.0-11-amd64
|
|
VirtualBox Guest Additions: Running kernel modules will not be replaced until
|
|
the system is restarted
|
|
waldek@hellodebian:/media/cdrom0$ sudo reboot now
|
|
```
|
|
|
|
Once the machine is rebooted you'll can resize the window and the screen resolution will adapt automatically!
|
|
You can also enable copy/paste and drag and drop between your host and VM now.
|
|
|
|
|