1 00:00:00,090 --> 00:00:01,440 In this lesson, we're going to 2 00:00:01,440 --> 00:00:02,670 discuss package managers 3 00:00:02,670 --> 00:00:05,280 and their use in the Linux operating system. 4 00:00:05,280 --> 00:00:07,440 These days, one of the most important elements 5 00:00:07,440 --> 00:00:09,600 of a computer is its software. 6 00:00:09,600 --> 00:00:12,240 The Linux operating system is known for its diversity 7 00:00:12,240 --> 00:00:14,820 and adjustability because of all the different pieces 8 00:00:14,820 --> 00:00:16,860 of software that you can install. 9 00:00:16,860 --> 00:00:20,280 Nevertheless, installing new software might be frustrating 10 00:00:20,280 --> 00:00:22,080 in the beginning for new users. 11 00:00:22,080 --> 00:00:24,510 But soon, as a Linux user and administrator, 12 00:00:24,510 --> 00:00:26,910 you're going to realize the unlimited options that you have 13 00:00:26,910 --> 00:00:28,980 in your hands, by being able to understand how 14 00:00:28,980 --> 00:00:31,380 to install different pieces of software. 15 00:00:31,380 --> 00:00:32,430 One thing you should be aware 16 00:00:32,430 --> 00:00:35,880 of upfront is that Linux does have multiple different ways 17 00:00:35,880 --> 00:00:37,710 of installing pieces of software. 18 00:00:37,710 --> 00:00:40,170 And these are known as package managers. 19 00:00:40,170 --> 00:00:42,780 Now package management is really important in Linux 20 00:00:42,780 --> 00:00:45,870 because each distribution does it slightly differently. 21 00:00:45,870 --> 00:00:48,330 And knowing how to use these different package managers 22 00:00:48,330 --> 00:00:49,890 can be really, really important 23 00:00:49,890 --> 00:00:52,650 for you as a power user or system administrator 24 00:00:52,650 --> 00:00:54,000 because you're going to have to download 25 00:00:54,000 --> 00:00:55,290 and install all these different pieces 26 00:00:55,290 --> 00:00:57,960 of software from repositories, update them, 27 00:00:57,960 --> 00:00:59,310 handle their dependencies, 28 00:00:59,310 --> 00:01:01,350 and then later on, uninstall that software 29 00:01:01,350 --> 00:01:02,820 when you no longer need it. 30 00:01:02,820 --> 00:01:04,470 And all this is done different ways 31 00:01:04,470 --> 00:01:05,850 depending on what distribution 32 00:01:05,850 --> 00:01:08,760 and what package manager you're going to be using. 33 00:01:08,760 --> 00:01:11,640 So in order to become a true Linux geek, 34 00:01:11,640 --> 00:01:13,230 it's really important to understand how 35 00:01:13,230 --> 00:01:16,290 these major Linux distributions handle packages 36 00:01:16,290 --> 00:01:18,630 in order to install the necessary applications 37 00:01:18,630 --> 00:01:20,910 and keep them updated over time. 38 00:01:20,910 --> 00:01:23,940 Linux distributions really rely on two different methods 39 00:01:23,940 --> 00:01:26,670 of managing software throughout its lifecycle. 40 00:01:26,670 --> 00:01:29,580 Package managers and compiling software. 41 00:01:29,580 --> 00:01:32,580 Now package managers refer to programs that install, 42 00:01:32,580 --> 00:01:36,390 update, inventory and uninstall package software. 43 00:01:36,390 --> 00:01:38,490 This governs the entire software lifecycle 44 00:01:38,490 --> 00:01:40,320 for you and makes it much easier 45 00:01:40,320 --> 00:01:42,660 for you to control what software is being installed, 46 00:01:42,660 --> 00:01:44,490 how you can manage software versions, 47 00:01:44,490 --> 00:01:46,740 and then later on, uninstall that software 48 00:01:46,740 --> 00:01:48,390 when you no longer need it. 49 00:01:48,390 --> 00:01:51,510 Now, when you compile software manually from source code, 50 00:01:51,510 --> 00:01:53,940 this is actually much more difficult. 51 00:01:53,940 --> 00:01:56,130 Because of the open source nature of Linux, 52 00:01:56,130 --> 00:01:57,780 this means that you can download any piece 53 00:01:57,780 --> 00:01:59,130 of code off the internet, 54 00:01:59,130 --> 00:02:01,950 you can compile it and then run it on Linux. 55 00:02:01,950 --> 00:02:04,290 But this is much more difficult than simply using 56 00:02:04,290 --> 00:02:05,850 a package manager and installing 57 00:02:05,850 --> 00:02:08,160 a pre-packaged piece of software. 58 00:02:08,160 --> 00:02:11,070 Now, many Linux applications are considered modular 59 00:02:11,070 --> 00:02:13,320 and they depend on other pieces of software that 60 00:02:13,320 --> 00:02:16,410 are already present on your system in order for them to run. 61 00:02:16,410 --> 00:02:18,930 The great thing about using a package is that it's already 62 00:02:18,930 --> 00:02:21,750 going to list out the dependencies, the required components, 63 00:02:21,750 --> 00:02:24,720 without you having to figure out all those things yourself. 64 00:02:24,720 --> 00:02:27,000 The package manager is going to check those dependencies 65 00:02:27,000 --> 00:02:29,460 before it installs the software from the package. 66 00:02:29,460 --> 00:02:30,870 And if you're missing any of them, 67 00:02:30,870 --> 00:02:32,670 it's going to go grab those dependencies 68 00:02:32,670 --> 00:02:34,290 and install them first. 69 00:02:34,290 --> 00:02:36,480 On the other hand, if you're manually compiling 70 00:02:36,480 --> 00:02:38,550 the software yourself, you're going to have to go 71 00:02:38,550 --> 00:02:41,370 and work through all those dependencies on your own. 72 00:02:41,370 --> 00:02:42,720 On modern Linux systems, 73 00:02:42,720 --> 00:02:44,040 there are two dominant methods 74 00:02:44,040 --> 00:02:46,080 for managing software packages. 75 00:02:46,080 --> 00:02:48,390 The first method is known as RPM, 76 00:02:48,390 --> 00:02:50,490 or the Red Hat package manager. 77 00:02:50,490 --> 00:02:53,250 The second is known as dpkg, 78 00:02:53,250 --> 00:02:55,650 which is the Debian package system. 79 00:02:55,650 --> 00:02:57,690 These two managers are significantly different 80 00:02:57,690 --> 00:03:00,300 from each other, but the functionality they use 81 00:03:00,300 --> 00:03:02,310 is actually going to be the same. 82 00:03:02,310 --> 00:03:03,630 As a Linux user, 83 00:03:03,630 --> 00:03:04,980 your choice will usually be driven 84 00:03:04,980 --> 00:03:07,140 by your preferred Linux distribution. 85 00:03:07,140 --> 00:03:10,680 For example, if you're using CentOS or Red Hat, 86 00:03:10,680 --> 00:03:14,370 you're going to be using RPM or the Red Hat package manager. 87 00:03:14,370 --> 00:03:16,290 If you're using something that is Debian based, 88 00:03:16,290 --> 00:03:20,130 like Kali Linux, or Debian, you're going to be using dpkg, 89 00:03:20,130 --> 00:03:22,710 or the Debian package management system. 90 00:03:22,710 --> 00:03:25,440 Now for the most part, you're probably going to be using one 91 00:03:25,440 --> 00:03:27,390 of these two package systems instead 92 00:03:27,390 --> 00:03:30,390 of compiling the code yourself from source. 93 00:03:30,390 --> 00:03:32,520 But there are some cases where you may want 94 00:03:32,520 --> 00:03:34,410 to compile things from source. 95 00:03:34,410 --> 00:03:37,110 This is because of the open source nature of Linux. 96 00:03:37,110 --> 00:03:39,000 You have access to the source code, 97 00:03:39,000 --> 00:03:40,170 and maybe there's some options that 98 00:03:40,170 --> 00:03:41,760 you want to enable or disable. 99 00:03:41,760 --> 00:03:43,710 You want to customize some choices inside 100 00:03:43,710 --> 00:03:45,660 of that software and things like that. 101 00:03:45,660 --> 00:03:48,360 In those cases, you can create those modifications 102 00:03:48,360 --> 00:03:50,910 to the source code and then compile the source code 103 00:03:50,910 --> 00:03:52,800 on your own system to run it. 104 00:03:52,800 --> 00:03:55,350 But again, manually compiling software does require 105 00:03:55,350 --> 00:03:57,240 more effort and more knowledge, 106 00:03:57,240 --> 00:03:59,910 but it can give you something that is really customized 107 00:03:59,910 --> 00:04:01,350 to your own needs. 108 00:04:01,350 --> 00:04:04,295 For the most part, though, probably 99% of the time 109 00:04:04,295 --> 00:04:07,170 you're going to be just fine using packages using 110 00:04:07,170 --> 00:04:09,960 either RPM or dpkg. 111 00:04:09,960 --> 00:04:12,030 Let's talk a little bit more about RPM. 112 00:04:12,030 --> 00:04:14,850 Now, RPM is the Red Hat package manager, 113 00:04:14,850 --> 00:04:17,880 and it's still in use today by many system administrators. 114 00:04:17,880 --> 00:04:19,410 Software packages that are prepared 115 00:04:19,410 --> 00:04:23,520 for RPM will have a file extension of .rpm. 116 00:04:23,520 --> 00:04:26,430 RPM is very flexible and very powerful. 117 00:04:26,430 --> 00:04:28,710 And one of the most useful features is the ability 118 00:04:28,710 --> 00:04:31,320 for it to inventory software on your system. 119 00:04:31,320 --> 00:04:33,660 This enables the system administrator to easily 120 00:04:33,660 --> 00:04:36,180 see what software is installed and what versions 121 00:04:36,180 --> 00:04:39,480 of those pieces of software are installed on a given system. 122 00:04:39,480 --> 00:04:42,270 There's actually a newer and more advanced package manager 123 00:04:42,270 --> 00:04:43,560 than the RPM. 124 00:04:43,560 --> 00:04:46,320 And this is also supported by all Red Hat derivatives 125 00:04:46,320 --> 00:04:48,960 including Red Hat Linux, and CentOS. 126 00:04:48,960 --> 00:04:53,040 This is known as YUM, the Yellowdog Updater, Modified. 127 00:04:53,040 --> 00:04:54,900 Now YUM does rely on RPM, 128 00:04:54,900 --> 00:04:57,810 and it still uses .rpm package files, 129 00:04:57,810 --> 00:04:59,400 but it offers a more elegant set 130 00:04:59,400 --> 00:05:01,290 of commands and greater flexibility 131 00:05:01,290 --> 00:05:02,970 for using software repositories 132 00:05:02,970 --> 00:05:05,310 and handling dependencies for you. 133 00:05:05,310 --> 00:05:07,770 Now just like YUM has replaced RPM, 134 00:05:07,770 --> 00:05:11,730 there's a newer version called DNF that is replacing YUM. 135 00:05:11,730 --> 00:05:15,660 DNF stands for the Dandified YUM package manager. 136 00:05:15,660 --> 00:05:18,510 It's an improved version of YUM and uses fewer resources 137 00:05:18,510 --> 00:05:20,130 while still maintaining support for 138 00:05:20,130 --> 00:05:23,340 the fundamental RPM package manager underneath. 139 00:05:23,340 --> 00:05:26,670 Most people find that DNF is easier to use than YUM 140 00:05:26,670 --> 00:05:28,860 because it has a more simplified set of commands 141 00:05:28,860 --> 00:05:30,840 while still being backwards compatible to most 142 00:05:30,840 --> 00:05:33,450 of the YUM sub commands if you're used to those. 143 00:05:33,450 --> 00:05:34,680 If you've been using YUM, 144 00:05:34,680 --> 00:05:37,200 moving to DNF is pretty easy. 145 00:05:37,200 --> 00:05:38,970 To install a package using DNF, 146 00:05:38,970 --> 00:05:42,510 simply type in dnf install and the package name. 147 00:05:42,510 --> 00:05:46,320 For example, dnf install Apache2 would install 148 00:05:46,320 --> 00:05:48,150 the Apache2 web server. 149 00:05:48,150 --> 00:05:50,220 If you want to uninstall a DNF package, 150 00:05:50,220 --> 00:05:53,280 simply type in dnf remove package name. 151 00:05:53,280 --> 00:05:57,060 So dnf remove Apache2 would uninstall 152 00:05:57,060 --> 00:06:00,330 the Apache2 web server from that Linux system. 153 00:06:00,330 --> 00:06:02,850 Now another package manager you may run across 154 00:06:02,850 --> 00:06:04,350 is known as Zypper. 155 00:06:04,350 --> 00:06:07,410 Zypper is a package manager that supports repositories, 156 00:06:07,410 --> 00:06:10,500 dependencies and management of the software lifecycle 157 00:06:10,500 --> 00:06:12,570 on an openSUSE system. 158 00:06:12,570 --> 00:06:15,180 This still does support .rpm packages, 159 00:06:15,180 --> 00:06:18,090 but it is specific to that Linux distribution. 160 00:06:18,090 --> 00:06:20,010 It's very efficient and it does a great job 161 00:06:20,010 --> 00:06:22,170 of managing package dependencies for you. 162 00:06:22,170 --> 00:06:24,480 But if you're not on an openSUSE system, 163 00:06:24,480 --> 00:06:26,250 you're probably not going to be using it. 164 00:06:26,250 --> 00:06:29,310 If you are on an openSUSE system, you can install a package 165 00:06:29,310 --> 00:06:33,090 by simply typing in zypper in and the package name. 166 00:06:33,090 --> 00:06:36,420 To uninstall a package, simply type in zypper rm 167 00:06:36,420 --> 00:06:37,563 and that package name. 168 00:06:39,120 --> 00:06:41,760 If you're using a Debian based Linux system though, 169 00:06:41,760 --> 00:06:43,980 you're going to be using dpkg, 170 00:06:43,980 --> 00:06:46,200 which is the Debian package manager. 171 00:06:46,200 --> 00:06:47,760 This is available in all Debian 172 00:06:47,760 --> 00:06:49,830 and Debian based Linux distributions. 173 00:06:49,830 --> 00:06:51,960 For example, Kali Linux is based 174 00:06:51,960 --> 00:06:55,650 on Debian and therefore it uses dpkg. 175 00:06:55,650 --> 00:06:58,980 The dpkg manager can control the entire software lifecycle 176 00:06:58,980 --> 00:07:03,030 for you just like RPM can, but it's done on a Debian system. 177 00:07:03,030 --> 00:07:06,960 Software packages are going to have the .deb file extension 178 00:07:06,960 --> 00:07:10,440 if they're able to be used with the dpkg software, 179 00:07:10,440 --> 00:07:14,550 because it's .deb for Debian package manager. 180 00:07:14,550 --> 00:07:16,620 The preferred method of package management, though, 181 00:07:16,620 --> 00:07:19,710 on Debian based systems today is actually using a tool known 182 00:07:19,710 --> 00:07:22,950 as APT, the advanced package tool. 183 00:07:22,950 --> 00:07:26,880 This is a more flexible tool than the dpkg package manager, 184 00:07:26,880 --> 00:07:30,180 but it still relies on .deb packages. 185 00:07:30,180 --> 00:07:35,180 Much like YUM still uses RPM, APT still uses .deb files. 186 00:07:36,780 --> 00:07:38,070 Okay, so as you can see 187 00:07:38,070 --> 00:07:40,560 there are lots of different package managers out there. 188 00:07:40,560 --> 00:07:42,270 But what it comes down to is 189 00:07:42,270 --> 00:07:45,420 that package managers are an easy way for you to install 190 00:07:45,420 --> 00:07:48,240 or remove software on a given Linux system. 191 00:07:48,240 --> 00:07:50,370 If you're using something that is Red Hat based, 192 00:07:50,370 --> 00:07:52,230 like CentOS or Red Hat, 193 00:07:52,230 --> 00:07:56,100 you're going to be using .rpm files using either the DNF 194 00:07:56,100 --> 00:07:58,170 or YUM package managers. 195 00:07:58,170 --> 00:08:00,540 If you're using a Debian based distribution, 196 00:08:00,540 --> 00:08:03,900 you're going to be using .deb files as your packages, 197 00:08:03,900 --> 00:08:08,013 and using tools like APT or the older dpkg.