1
00:00:06,840 --> 00:00:07,673
- In this video,

2
00:00:07,673 --> 00:00:10,200
we are going to explore
how to work with packages

3
00:00:10,200 --> 00:00:11,743
using YUM and DNF.

4
00:00:13,022 --> 00:00:15,750
YUM and DNF are specific for Red Hat.

5
00:00:15,750 --> 00:00:19,740
And YUM is using all the
versions of Red Hat and family.

6
00:00:19,740 --> 00:00:22,893
The YUM backend recently
has been replaced with DNF.

7
00:00:23,790 --> 00:00:27,630
DNF is a preferred tool
in current RHEL versions.

8
00:00:27,630 --> 00:00:30,540
But as of now, DNF, as well as YUM,

9
00:00:30,540 --> 00:00:33,930
are basically providing
the same functionality.

10
00:00:33,930 --> 00:00:35,550
And that is because both commands

11
00:00:35,550 --> 00:00:38,850
are using a symbolic
link to the same binary.

12
00:00:38,850 --> 00:00:40,650
So if you wanna be cool,

13
00:00:40,650 --> 00:00:44,223
you should use DNF utility,
but really it doesn't matter.

14
00:00:45,060 --> 00:00:46,950
Now DNF uses repositories.

15
00:00:46,950 --> 00:00:48,480
And the repositories by default

16
00:00:48,480 --> 00:00:52,500
are in the directory /etc/yum.repos.d.

17
00:00:52,500 --> 00:00:54,570
These are text based configuration files

18
00:00:54,570 --> 00:00:57,063
in which you configure your repositories.

19
00:00:57,960 --> 00:01:01,263
The dnf command was really
written to be intuitive.

20
00:01:02,160 --> 00:01:05,430
Like you want to install
a package, dnf install.

21
00:01:05,430 --> 00:01:08,790
You want to look up a package, dnf search.

22
00:01:08,790 --> 00:01:11,223
You want to remove it, dnf remove.

23
00:01:12,570 --> 00:01:15,300
DNF also allows working
with package groups

24
00:01:15,300 --> 00:01:18,930
to make installation of
specific functionality easier.

25
00:01:18,930 --> 00:01:20,460
So if you work with a package group,

26
00:01:20,460 --> 00:01:23,040
you don't have to focus
on individual packages.

27
00:01:23,040 --> 00:01:25,320
You focus more on functionality.

28
00:01:25,320 --> 00:01:28,350
So you would use dnf groups
list for a list of groups.

29
00:01:28,350 --> 00:01:30,270
and then you can install
the complete group

30
00:01:30,270 --> 00:01:32,223
using dnf groups install.

31
00:01:33,210 --> 00:01:35,010
There is also yum modules.

32
00:01:35,010 --> 00:01:36,660
yum modules provide a way

33
00:01:36,660 --> 00:01:39,300
to install different versions of packages,

34
00:01:39,300 --> 00:01:42,930
including all of the
required dependencies.

35
00:01:42,930 --> 00:01:46,350
In order to work with modules,
you use yum module install

36
00:01:46,350 --> 00:01:49,230
like yum module install container-tools.

37
00:01:49,230 --> 00:01:51,270
And the cool thing about these modules

38
00:01:51,270 --> 00:01:54,990
is that the Red Hat family
distribution, by using modules,

39
00:01:54,990 --> 00:01:59,520
is capable of providing different
versions of vital packages

40
00:01:59,520 --> 00:02:02,190
like Python and Pearl, for instance.

41
00:02:02,190 --> 00:02:04,200
You wanna use Python 3.6?

42
00:02:04,200 --> 00:02:07,470
Use the yum module for Python 3.6.

43
00:02:07,470 --> 00:02:08,850
You wanna use 3.8?

44
00:02:08,850 --> 00:02:11,433
Use the yum module for Python 3.8.

45
00:02:12,810 --> 00:02:15,540
Now, if you are working with YUM and DNF,

46
00:02:15,540 --> 00:02:19,440
then it might be convenient
to find the right package.

47
00:02:19,440 --> 00:02:21,120
Sometimes that's not that easy.

48
00:02:21,120 --> 00:02:22,590
Sometimes dnf search

49
00:02:22,590 --> 00:02:24,780
doesn't give you the
package that you need.

50
00:02:24,780 --> 00:02:26,880
Then it's good to know,
that as an alternative,

51
00:02:26,880 --> 00:02:29,340
you can use dnf provides.

52
00:02:29,340 --> 00:02:33,570
dnf provides allows you
to search on a file name.

53
00:02:33,570 --> 00:02:35,040
That can be any file name.

54
00:02:35,040 --> 00:02:38,280
Specify the file name
using */, name of the file.

55
00:02:38,280 --> 00:02:40,710
And you will see the matching package.

56
00:02:40,710 --> 00:02:42,870
And also nice is dnf history.

57
00:02:42,870 --> 00:02:46,770
That allows you to undo
changes recently applied

58
00:02:46,770 --> 00:02:49,170
by using these packages.

59
00:02:49,170 --> 00:02:51,020
Let me show you how to work with YUM.

60
00:02:53,760 --> 00:02:54,593
All right.

61
00:02:54,593 --> 00:02:59,420
Let me use sudo yum search, search what?

62
00:03:00,690 --> 00:03:04,800
Well, let's do nmap for
instance, and there we go.

63
00:03:04,800 --> 00:03:08,340
If you do sudo yum search,
we get a result like this.

64
00:03:08,340 --> 00:03:12,120
So nmap, this is the nmap that was found.

65
00:03:12,120 --> 00:03:16,370
Network exploration tool
and security scanner.

66
00:03:16,370 --> 00:03:20,608
That's a description that
we've got about nmap.

67
00:03:20,608 --> 00:03:22,168
Then we have nmap-ncat.

68
00:03:22,168 --> 00:03:23,310
What is that?

69
00:03:23,310 --> 00:03:25,860
That is another package that was found.

70
00:03:25,860 --> 00:03:27,840
So we have a name, exact match,

71
00:03:27,840 --> 00:03:29,640
and we have a name and summary match.

72
00:03:29,640 --> 00:03:31,980
So the exact match is the most likely,

73
00:03:31,980 --> 00:03:34,533
the name and summary is
a little bit less likely.

74
00:03:35,460 --> 00:03:37,290
So use this on anything,

75
00:03:37,290 --> 00:03:39,990
but sometimes if you use yum search,

76
00:03:39,990 --> 00:03:42,990
I'm using yum search seinfo, for instance.

77
00:03:42,990 --> 00:03:44,010
Now, what do we get?

78
00:03:44,010 --> 00:03:46,773
We get a No matches found.

79
00:03:47,760 --> 00:03:49,380
That is because yum search

80
00:03:49,380 --> 00:03:52,410
is not doing a deep
inspection of your packages.

81
00:03:52,410 --> 00:03:56,310
If I want to search for
packages containing a file

82
00:03:56,310 --> 00:03:58,380
then I should do two things.

83
00:03:58,380 --> 00:04:02,700
First, I need to replace
the seinfo with */seinfo.

84
00:04:02,700 --> 00:04:04,740
That's a mandatory pattern.

85
00:04:04,740 --> 00:04:07,350
And next I can use provides.

86
00:04:07,350 --> 00:04:11,490
So sudo yum provides or dnf
provides if you want to.

87
00:04:11,490 --> 00:04:14,490
And then we see that setools-console

88
00:04:14,490 --> 00:04:17,340
is the package that we want to install.

89
00:04:17,340 --> 00:04:22,340
So I can use sudo yum
info on setools-console

90
00:04:22,380 --> 00:04:24,030
to get more information.

91
00:04:24,030 --> 00:04:26,760
And there we go, a little
bit more information.

92
00:04:26,760 --> 00:04:30,120
And if I decide that this
is really what I want,

93
00:04:30,120 --> 00:04:35,120
then I'm going to use sudo yum
install -y setools-console.

94
00:04:41,640 --> 00:04:43,470
So what is this -y about?

95
00:04:43,470 --> 00:04:44,550
Well, let me show you.

96
00:04:44,550 --> 00:04:48,603
I'm just going to not
include the -y option.

97
00:04:49,440 --> 00:04:51,720
If you do not include the -y,

98
00:04:51,720 --> 00:04:54,108
then the command is prompting you

99
00:04:54,108 --> 00:04:56,190
about what it's going to do.

100
00:04:56,190 --> 00:04:58,440
And then it's asking you, is that okay?

101
00:04:58,440 --> 00:05:01,110
If you wanted to immediately install,

102
00:05:01,110 --> 00:05:02,730
then you can use the -y.

103
00:05:02,730 --> 00:05:05,220
It won't prompt, it'll
just do the installation.

104
00:05:05,220 --> 00:05:07,623
And there we go, the package is installed.

105
00:05:08,670 --> 00:05:10,650
Let me do a sudo yum history

106
00:05:10,650 --> 00:05:13,200
to see what has recently happened.

107
00:05:13,200 --> 00:05:16,260
And there, we can see
the history of packages

108
00:05:16,260 --> 00:05:20,160
that recently has been applied.

109
00:05:20,160 --> 00:05:24,930
Now with YUM, you can also do
things like sudo yum upgrade.

110
00:05:24,930 --> 00:05:26,820
And yum upgrade is doing what?

111
00:05:26,820 --> 00:05:29,910
It's checking on all the
packages currently installed.

112
00:05:29,910 --> 00:05:33,090
And, wow, we can see 681,

113
00:05:33,090 --> 00:05:36,240
and we can upgrade them if we want to.

114
00:05:36,240 --> 00:05:37,410
Do I really want that?

115
00:05:37,410 --> 00:05:39,000
No, I don't think so.

116
00:05:39,000 --> 00:05:42,360
681 megabytes, too much data traffic.

117
00:05:42,360 --> 00:05:44,820
I don't wanna do that right now.

118
00:05:44,820 --> 00:05:46,860
Now how about these yum groups?

119
00:05:46,860 --> 00:05:49,350
sudo yum groups list.

120
00:05:49,350 --> 00:05:50,183
There we go.

121
00:05:50,183 --> 00:05:52,560
We have the different yum groups.

122
00:05:52,560 --> 00:05:57,270
So if I wanted to install
System Tools for instance,

123
00:05:57,270 --> 00:06:02,167
sudo yum groups install system,

124
00:06:02,167 --> 00:06:05,250
oh, system tools,

125
00:06:05,250 --> 00:06:07,650
what do you think, is that going to work?

126
00:06:07,650 --> 00:06:10,410
Well, I have my opinion about it,

127
00:06:10,410 --> 00:06:12,420
but let's just have a look.

128
00:06:12,420 --> 00:06:13,290
And what do we see?

129
00:06:13,290 --> 00:06:15,810
We see module or group
system is not available.

130
00:06:15,810 --> 00:06:18,780
Module or group tools is not available.

131
00:06:18,780 --> 00:06:21,600
We are having a problem
here because of the space.

132
00:06:21,600 --> 00:06:22,770
In these yum groups,

133
00:06:22,770 --> 00:06:25,050
if you want to install a yum group

134
00:06:25,050 --> 00:06:28,020
that has a space in the
name, use double quotes.

135
00:06:28,020 --> 00:06:28,980
And there we go.

136
00:06:28,980 --> 00:06:30,486
And you can see that everything

137
00:06:30,486 --> 00:06:34,590
that is a part of this yum
group is now installed.

138
00:06:34,590 --> 00:06:38,220
That just takes a minute and
should not take too long.

139
00:06:38,220 --> 00:06:40,410
There is one more thing
that I want to show you

140
00:06:40,410 --> 00:06:42,150
and that is the repository.

141
00:06:42,150 --> 00:06:45,390
So repositories on a YUM based system

142
00:06:45,390 --> 00:06:50,310
are in /etc/yum.repos.d/.

143
00:06:50,310 --> 00:06:52,320
And in /etc/yum.repos.d/,

144
00:06:52,320 --> 00:06:55,170
we see the repositories.

145
00:06:55,170 --> 00:06:56,694
So I'm on CentOS.

146
00:06:56,694 --> 00:07:00,660
And the CentOS repository
is defined in centos.repo.

147
00:07:00,660 --> 00:07:02,580
And here we can see an exact reference

148
00:07:02,580 --> 00:07:05,310
to the repositories which are online

149
00:07:05,310 --> 00:07:08,280
that are going to be used
by this CentOS system.

150
00:07:08,280 --> 00:07:10,050
I think this is enough about YUM,

151
00:07:10,050 --> 00:07:11,850
should be enough to get you started.

152
00:07:11,850 --> 00:07:13,473
Let's go check out APT.