Linux Package Managers (Linux+ Objective 1.6.1)

Hello, everybody. I'm Shawn Powers, and

today we are talking about packages.

Oh my God. Look at my package.

No. We're talking about Linux packages--

specifically RPM and DEB-based package

management as part of the Linux+

exam objectives. Whether or not you want

to take the exam, that's what we're basing this video on. So we're going to

look at package management using

multiple tools: DNF, YUM, APT, Zypper, and

we're going to look at the two different

types of packages that are specified here--RPM, and then it doesn't spell it

out, but DEB packages for .deb files. And that's what we're going to look at.

Even though there are other options out there

for package management, these are the

main ones that we're going to look at.

They're the most common. They're used in

Red Hat variants and Debian variants

like Ubuntu, etc. And we're going to talk

just briefly about these. This is an odd sort of thing they added on to the

objectives, but kernel updates generally

require a reboot--not always, but almost always.

They’ll require a reboot, and they'll have to rebuild a bunch of modules.

So this isn't necessarily done every time

you update your system. You can update

packages either--depending on your distribution--you can update all the

packages, or you can update only the packages that need security updates.

There are several different ways you can go about updating packages and

kernel updates. And the most important

thing is to make sure that you have the most recent versions if there are

security fixes. But we're going to look at a bunch of different tools that you

can use to manage packages on your system, because by default, just

managing individual packages is not the way to go. Like I said, we're

going to look at DEB files like .deb, which comes from Debian, and

then .rpm, which stands for Red Hat Package Manager.

Back in the old days, there didn’t use to be this big

database-driven way to install and manage things on your system.

You used to have to install the .rpm or .deb

files, and it was really a pain in the butt because an individual RPM file or

DEB file does not necessarily contain all the dependencies.

Although they do know what dependencies they require,

if you try to install them manually, you

end up with a nightmare. Let me show you

what I mean. First, we'll start with Rocky Linux,

which is the same as Red Hat. So it uses RPM. Like I said, this is Rocky

Linux, which is just like Red Hat Enterprise Linux version 9.

I think this is Rocky version 9. Anyway, in here, I have an RPM file.

Now, this is not normally how you would get a file

installed on your Linux system, but it used to be this way. And occasionally,

you'll have to install an RPM. But let's

say we had this RPM file and we wanted to install it using just the RPM tools--

not the package management system.

Well, we would do: sudo rpm -i for install

and then the file that we want to install.

And now, if there are no dependencies or all the dependencies are

already installed on your system, hey--no

problem. However--well, I’ve got to put in my password--

you'll see here it's not going to install because we also have to have

libteam and libteam.so.5, which is probably part of the libteam file.

Yeah. That’s actually what it's saying.

It needs it from the libteam file. So what

we would have to do is go online and

try to find the proper version of libteam.rpm with the exact version

that we're looking for on the repos.

We would install that. And then, if that has

its own dependencies, we end up in something that used to be called "RPM

Hell." It was kind of a play on the term "DLL Hell," which is what Windows

users would talk about—like, "This DLL (Dynamic Link Library) in Windows

interferes with that DLL, and so I can't

have them both installed, and I can't get

my package to work," etc., etc. So this used

to be a very frustrating way to install

packages. And, of course, it's not limited

just to RPM-based things. The same thing is true on a Debian or Ubuntu

system that uses DEBs. So here, I'm on an

Ubuntu system which uses .deb files,

and you'll see I've already downloaded one.

This is curl, like the curl we talked about in a previous video. curl is used to

fetch a URL or a file online.

The curl program, though--to install it--we

could use the dpkg program, which manually

handles .deb files. So we could do: sudo dpkg -i for install and then this

file, curl, blah, blah, blah, blah, blah, and

we'll press enter. And if there were no

dependencies that were unmet, it would have installed and been available on our system to use.

However, just like with that RPM file,

this says: "Well, no. This depends on libcurl4." So, in the old days, we’d

have to go and find libcurl with the exact version it's looking

for, install that .deb file. Of course, that .deb file might have some other

dependency--like libcurl might depend on

glibc or something--and we’d have to find

that one and go all the way back until all the dependencies were met.

But thankfully, there is a better way.

In fact, there are quite a few better ways.

Because in the world of RPMs--like using Red Hat

or Rocky Linux, or even SUSE Linux, which

also uses the RPM system--there are package management systems that kind of

wrap around RPMs or DEBs, in the case of a Debian-based system.

And they kind of keep a database of all the

available packages on a repository on the Internet. When you say, "I want to

install something," it says, "Okay, what other dependencies are there?"

Then it finds all of those dependencies,

downloads and installs them, so you

don't have to track down each individual

one. It has made managing Linux so much better than it used to be.

But there are a lot of ways to skin the same cat--which is a horrible, horrible metaphor.

I don't like that. There are a lot of ways to manage packages in Linux.

I’ll show you the various ways mentioned in the

objectives, but note that there are others. Like,

if you're using Arch Linux, there's going to be Pacman.

We're not covering that. We're just going to cover the ones mentioned

in the objectives--and they are the most common.

So, for example, we're back here.

We're on Rocky Linux, which, like I said,

is just like Red Hat Linux. And instead

of using the RPM tool, we can say: "Oh, well,

there are two different tools that come with Red Hat variants," which is

interesting. One is yum, which stands for Yellowdog Updater Modified.

There's another whole story there. And the other

one is dnf, which was written by Red Hat,

and it stands for Dandified Yum, which I think is a little bit silly. dnf is newer.

It's the one that you should be using on

a Red Hat-based system because it has a

few more features--like the ability to roll back if you want to make a change.

I'll show you what I mean. But first of all, to install--let’s say--this

teamd thing that I had downloaded, we could say:

sudo yum install teamd

And this is the difference. See, we

couldn't install it before because there

were dependencies. The dependencies were

libteam. And like I said, libteam might

have its own dependencies--and sure enough, it does. If you look,

libteam apparently depends on libnl3-cli.

But the nice thing about using a package management system like YUM is

that it gets all of those dependencies and installs all of them.

So, in order to use YUM to install this teamd

package that I just randomly picked, I would just say "yes," and it would download

all of the packages required, install the dependencies, and then install that

package. Now, I'm going to say "no," not

because this doesn't work--this would

work perfectly fine--but I want to show

you how you would do the exact same thing using DNF.

In fact, the command-line flags are almost identical

when you're using DNF or YUM. So let's say:

sudo dnf install teamd.

And by looking at it, it even looks exactly the

same, right? It just has some more features.

So it's YUM, but "dandified"--thus the name, DNF.

um and this is going to do the exact

same thing it's going to download the

dependencies we'll actually do it this

time but it does the same thing whether

you're using yum or dnf

um it's saying that there is a gpg key

do I want to import that I'm going to

say yes I want to import that and boom

there it is installed it and now it's

running and it keeps up it keeps like a

database of everything that is installed

on the system so the next time we

install something if one of its

dependencies is this team D or or lib

team or whatever it was it'll say oh

that's already installed I don't need to

download that so like I said yum and dnf

are almost exactly the same when you're

using them on the command line it's very

possible that yum will go away in the

future right now it's still installed

it's still perfectly cromulent way to

you know manage the packages on your

system and you can mix or match you

could use yum and then you could use dnf

they have the same database of

information that they pull from so you

can use either or right now but it would

not surprise me if yum goes away at some

future version of red hat stuff it's

just been replaced by dnf so there's no

reason not to use dnf and dnf will do

like I said it will roll back it'll

allow you to take back uh like if you

install something in your side you want

to undo that dnf allows you to do that

whereas yum does not and that really is

one of the big differences between the

two is dnf has more features that being

a main one but whether you're using dnf

or yum you can do things like update

which will update all the packages on

your system if you say update and a

package name it will only update that

one package I'll show you really quick

how to do the rollback because since we

use dnf we could roll back so we're back

here on the system that we just

installed uh Team D Actually I don't

even know what team D is but you just

installed that and now if we do dnf now

we don't have to be root to do this one

but we could say dnf

history

and it's going to show us the stuff that

it did now it says it shows a full

history you're going to see that before

the video I actually removed Team D so

that all this would work but this shows

a history of all the things that have

been done with dnf on the system and

since we see that this was done the

install Team D was um ID number three so

we can say now this does require sudo

because it's going to make some

system-wide changes we could say sudo

dnf history undo and then the number

three that last thing if we do that

it's going to remove the packages and

the dependencies that we just installed

basically it's going to just roll back

exactly what we just did

so I'm going to say yes

and now we have we don't have Team d

installed anymore so that's one of the

advantages of dnf over yum when it comes

to upgrading packages on your system

whether you're using yum or dnf there

are two very similar sounding and kind

of confusing terms you can either do uh

yum or dnf update and if you do that if

you specify a package it's just going to

update that one package but if you do it

without any other you know things at the

end just update and press enter it's

going to update all of the packages on

your system which is normally what you

want to do normally you want to update

all the packages to get them up to date

and you can see there's a whole bunch of

them it actually shows you different

kinds like it's going to install a new

kernel because there's a new kernel and

then it will activate that so I'll have

to restart it's going to upgrade all

these packages and it's going to install

these dependencies down here because the

new updated packages require updated

dependencies as well so you can can do

update and that's pretty safe the other

thing the other option that you have I'm

going to say no here the other option

you have and again whether using dnf or

yum so we'll use dnf this time just

because you can say upgrade instead of

update and the difference here is that

it's going to allow the system to get

rid of obsolete packages and these are

packages that are obsolete no longer

like current however it's possible that

some of those packages are things you're

still using so it's a little more

dangerous to do upgrade a lot of times

if you have update upgraded from like

red hat 8 to Red Hat 9 on your system

you can do upgrade and it will get rid

of obsolete packages and replace it with

updated ones but just know that it could

break stuff if you're actually using

those older packages so upgrade is

generally not used as much as update on

a red hat system but we'll say upgrade

and it's going to do the exact same

thing in this case it's the same

packages there aren't any the obsoleted

ones that it's you know worrying about

getting rid of because again we're not

changing anything drastic on our system

and so it's going to do the exact same

thing but just know that upgrade has the

potential to Break Stuff uh easier than

update does and it I hate that it's like

such similar words but the thing is

upgrade think of it as like I upgraded

to a new version of the Linux system as

opposed to just updating my current

packages maybe that'll help anyway we

say why it's going to go download all of

the stuff it's going to install it again

in this case it's a kernel package that

it's updating and going to recompile all

the all the modules that it needs to and

it will tell us that we need to reboot

in order to you know complete and

activate it and so if that's the kind of

thing that it's a production system you

might have to time when you can upgrade

it if it's going to require a reboot now

you probably remember that I said Souza

Linux also uses RPM and that's true the

underlying packages are RPM on Azusa

Linux box however it does not use yum or

dnf to manage the packages it uses

something called zipper and so I'll show

you that again the underlying stuff is

still RPM files and that's how it you

know maintains its packages but the

actual system to keep track of

dependencies and what's installed and

and where all the repositories online

are and stuff that uses the zipper

program which is completely different

from red hat or rocky Linux so I'm here

on open Souza and this is again an RPM

based system but it uses zipper and

zipper has slightly different commands

in order to do things rather than just

update and upgrade there are update or

just up it allows you to use shortcuts

there is dist upgrade which is very

rarely used and that's the same sort of

thing where it can remove packages for

you uh even if you don't want it to so

we don't normally do dist Dash upgrade

but zipper or open Souza has another

option that red hat does in it that's

called patch and patch basically just

installs the very important things like

security updates and stuff that you know

if there's a security release that has

to be installed even on a production

system you can do patch and it will

install those without updating all of

the other packages that may have updates

but they're not like super important

they're not security related updates so

patch is something that you can use more

often on a production system knowing

that it's just going to update the

things that are a security risk on your

system it's kind of cool actually and it

works similarly uh sudo z y p p e r is

the program instead of dnf or yum it's

zipper and then you can do things and I

didn't show you this with yum and dnf

but you can search for a package too so

we'll do it here it works the same on

the others I mean you can play with it

and look at the man page but we can say

search for Firefox I guess oh and this

is something it says sudo password for

root but it's my local password that it

wants that's just some weird open Sousa

thing and it looked in its repositories

and these are the things that it found

so we could install for example uh

Mozilla Firefox we can install using

zipper and it's going let's let's do it

sudo

zipper

install or you can just do in it they're

real big on like shortcuts but I I mean

it's confusing enough having multiple

ways to install packages on multiple

distros so I'm just going to type the

whole thing

install

Mozilla

Firefox now it did the exact same thing

it found any dependencies that it might

need and it did find a dependency it

said it's going to install the following

two packages this package and this

package in order to get the Mozilla

Firefox and it looks like it's going to

upgrade it it looks like it's already

installed which is fine so do I want to

do this why is the default but I'm going

to say yes it's going to download all of

those things it's going to install it

um and I shouldn't have said yes because

I'll just I'll fast forward I won't make

you wait but oh really quickly look you

see it's downloading RPM files so it is

using an RPM system underneath so I'm

glad I hit enter so I can show you that

um so okay that's installed we could do

the same thing with you know update or

or dist upgrade but the one thing that's

kind of unique here sudo

zipper

patch what this will do is it will

there's nothing to do there are no

security issues currently on on the

system that a patch would would do so we

can even if you know there are upgrades

available or updates available for our

packages we don't have to necessarily

install them on a production system

because there are no security ones

currently available hopefully that makes

sense that's a again a big deal but we

could do sudo

zipper

update and this will update all the

packages that are available to update

and you can say if we if we hit yes here

it's going to get 232 packages to

upgrade three of them new one of them is

going to change its architecture

interestingly enough but notice here it

says open Sousa Tumbleweed requires a

zipper

dup dup again they're all about

shortcuts is short for dist Dash upgrade

and that's because Tumbleweed I'm

getting in the weeds here with Souza but

in the weeds I didn't even mean that um

it's a it's a rolling distribution and

so that means that we're basically going

to upgrade will be more more common

because it it doesn't like have releases

it just is a rolling release so to fully

upgrade Tumbleweed we will do dist

upgrade or just dup it's shortcut so I'm

going to say no just so I can show you

that and then we'll be done sudo zipper

I could do dupp but again I don't like

that dist upgrade and this is going to

go through and now install again it's

installing the same packages it's just

telling you like hey when you have

Tumbleweed the rolling distribution you

should use dist upgrades so you know do

it that way you will usually we don't

use that in a production server

environment anyway but nonetheless

that's the difference between the two we

can press enter and it's going to

upgrade all of the things but it does

tell us that a system reboot is going to

be required because it's installing a

new kernel which is awesome information

for it to tell us in advance and that

leaves us with the system that I

actually prefer I use the most is a

Debian based system or dot Deb files

using apt and apt is the package

management system for Dev files uh apt

is used in Ubuntu and Debian there are

some others like apt-get is kind of a

package management system that uses the

app database and just like you can use

yum and dnf at the same time you can use

apt and apt-get and it just writes to

the same database so you can use either

one apt alone apt is the most recent one

and it's the one mentioned in the

objective so that's what I'm going to

show you that's what I use and there are

a couple nuances with dev-based systems

versus RPM based systems and the biggest

difference and this really is a big

difference is that with yum and dnf and

zipper when you search for a package or

install a package before it does

anything those systems will go and

refresh everything on the web like they

will get an update of all of the

available packages and versions but with

an apt-based system

that's an extra step you actually have

to refresh the what is available

database and to do that sudo apt update

so in this case update means I want to

update my cached information of packages

that are available and what versions are

on my repositories on the internet so it

means something drastically different

but it's important to do this first

because if you don't update then you

have old information you don't know what

packages are available so sudo apt

update oh come on there finally and it

will get you know it'll refresh its

cache of what stuff is available this

goes pretty quick as you can see it's

already done and now we can use apt to

upgrade or dist upgrade and this is

similar in that like the the different

degrees of upgrade because upgrade is

going to do all the packages that have

updates but it's not going to allow it

to remove package is and like do big

changes this is the same sort of thing

generally dist upgrade in an app system

is a little more dangerous and dangerous

isn't really a good word but it's it's

more apt and that's too punny for me to

say it's possible that if you do dist

upgrade it might break packages on your

system but if you're doing like going

from one like version to another dist

upgrade will bring all of your packages

up to the current distribution numbers

versions by removing old stuff and

installing the new versions of them if

they exist that sort of thing so

generally you just do upgrade but dist

upgrade is available if you have like a

drastic change that you've done and so

we can simply do sudo apt upgrade oh

when we used D package to install curl

uh it screwed up the database uh you

remember earlier when I try to do it

manually it actually screwed it up and

so what we can do we could say

pseudo apt Dash F install and it will

fix what I broke in fact in this case

it's going to install curl properly by

getting its its dependencies so I'm

going to say yes and uh that's a really

nice feature that it will clean up my

mess because I tried to do it manually

even though I would never do that in

real life I was showing you kind of the

old way that we had to do it anyway so

it's fixed that and now I can actually

run upgrade and it'll say okay there are

75 upgrades uh five new installs three

are not upgraded 30 are standard

security updates and so this is how you

can keep your system up to date it says

that these have been held back if we

were to do dist upgrade these would also

be upgraded but again it has the

potential to break your system maybe

um yeah it's it's kind of a frustrating

thing generally you can avoid disk

upgrade and just do upgrades and you'll

be fine so that's pretty much what we

would do here I just press enter it's

going to go and upgrade all the stuff so

depending on your system you have lots

of options for package management the

big thing to remember is on a Debian

based system so using apt you have to do

apt update and then apt upgrade in fact

you have to do apt update before you do

like an apt install so like if we were

to do apt install Firefox we'd have to

do apt update first otherwise it's going

to try to pull an old version that

doesn't exist anymore so you always need

to do apt update before you make any

changes to your system it's funny that

yum and dnf and zipper all do that step

automatically and app just doesn't but

that's how it is with great power comes

great responsibility and this is one of

those examples anyway I hope that was

helpful I encourage you to play with the

different tools to see what they can do

and the different options and and how

they work differently install a couple

systems distributions in a virtualized

environment so if you break it you know

so what and just have fun but as always

learn everything

do what you love and most importantly be

kind I'll see you in the next video