No OneTemporary
Actions

Subscribers

None

File Metadata

Created: Fri, Apr 19, 04:30

View Options

	diff --git a/assets/incident.png b/assets/incident.png
	new file mode 100644
	index 0000000..c4c9fba
	Binary files /dev/null and b/assets/incident.png differ
	diff --git a/assets/mount.svg b/assets/mount.svg
	new file mode 100644
	index 0000000..2ee197d
	--- /dev/null
	+++ b/assets/mount.svg
	@@ -0,0 +1,2 @@
	+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
	+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="661px" height="291px" viewBox="-0.5 -0.5 661 291" content="<mxfile modified="2019-01-15T20:48:51.544Z" host="www.draw.io" agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36" version="10.0.41" etag="PH30YfowH-HbxvlUZqgt" type="google"><diagram id="AV7xGsnJl9lvWWj9r5ga">7VlLj9sgEP41OW5k8CPe4+bVHrbSSntoe6qITWxabFJMEru/vmDj+JlVpLUTNdtcAh/DwMx8A0wyMRdR+omjXfiF+ZhOoOGnE3M5gRBY0JFfCskKxAVGAQSc+FqoAl7JH6zBUmxPfJw0BAVjVJBdE/RYHGNPNDDEOTs2xbaMNlfdoQB3gFcP0S76lfgi1FbYRoV/xiQIy5WBoUciVAprIAmRz441yFxNzAVnTBStKF1gqpxX+qWYtz4zetoYx7G4ZAIsJhwQ3WvbJtChcurcJwe1P5Fpo53fe7WpucCpeECUBPHEfFI+lithXo3LVqC/cz3JDsW9irYsFg9JHlulR+467WpZE4qTLBE4kiKg1CntKdQ2l5JwvusShY11IWf72MfKcEMOH0Mi8OsOeWr0KHkqsVBEVPaAbB4wF0RG/KmwdCmYEqBog+kLS4ggTKHa+Er8uSUQEd9X68+1x5YUb7VXPBIHz3lv6Sh3EEoXjDKeb1ZiK3u9Ppmh9OP0bJDBiToy5zCLsOCZFNETSrJlJzoW/WPFXcfRWFjjLXzUINL5EpxUV5SSDc2qfoaZ/xLD4Adi2Ho9t+e2khSc/cK1EX/2uDGMYbhnArtBPmh0yQdNu0s+4AxAPuss+RQ3LiIN7CON2kBFiULXEJxohWi7xY7njR6i9vkAuyGyeo4Ha4AA2SMFSF3p+ZlxhRht4ZkYORvHdoaJEWjFqC+N3JFi5HT8hX35HNJdxkXIAhYjuqrQedOjNe/hlIhvCp7auve9NrJM9Yy8k5WdWO64Nkl1v9fHqml5r5z3EwuR6dcj2gsmoWq3z0ydt/nKhX3KqEZ0ErbnnoZm+pWJeIDLgM0uDiLHFAlyaKp/T0hmI6UNipkIMf9xb+ljuq30sbrpA/qeQEPkj3ul/HkjSwbMBKubCfbtEuHx3n07wiGTT33iHGU1gR0jsUhqml8UUMsgq/VIcFuFZUvect6Ul41iB1WUT6ZcFPiyhvnQtxIAXcIA93bZWO5n8Hsp2W/u7UqyWzeS23MjwZFuJACHTJ4BCW338Plyzw7P5/M/XryzPCFy1hWo7NvY9a0+KrtwYzpDFSft19VVuWzd1ROgLwPMG2bAWAX6dDq90lkuP30JYOSfgc7ydgJcsToH1yrPb/YEBjesL8DolfZd3QTtOtvsSYTR6uzy5fv/rHorRLNWhHp+CRnoqJLd6o/MosSr/g42V38B</diagram></mxfile>" style="background-color: rgb(255, 255, 255);"><defs/><rect x="0" y="0" width="660" height="290" fill="#d6e5ff" stroke="#000000" pointer-events="none"/><g transform="translate(8.5,7.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="112" height="22" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 113px; white-space: nowrap; overflow-wrap: normal;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><div style="text-align: center"><span style="font-size: 20px">Filesystem 1</span></div></div></div></foreignObject><text x="56" y="17" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g><rect x="295" y="90" width="235" height="160" fill="#ffb5b5" stroke="#d79b00" pointer-events="none"/><g transform="translate(303.5,97.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="112" height="22" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 113px; white-space: nowrap; overflow-wrap: normal;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><div style="text-align: center"><span style="font-size: 20px">Filesystem 2</span></div></div></div></foreignObject><text x="56" y="17" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g><rect x="300" y="10" width="40" height="40" fill="#ffe6cc" stroke="#d79b00" pointer-events="none"/><g transform="translate(316.5,17.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="6" height="24" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 8px; white-space: nowrap; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><font style="font-size: 22px">/</font></div></div></foreignObject><text x="3" y="18" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g><rect x="100" y="90" width="80" height="40" fill="#fff2cc" stroke="#d6b656" pointer-events="none"/><g transform="translate(111.5,97.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="56" height="24" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 56px; white-space: nowrap; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><font style="font-size: 22px">folder</font></div></div></foreignObject><text x="28" y="18" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g><path d="M 440 170 L 440 183.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 440 188.88 L 436.5 181.88 L 440 183.63 L 443.5 181.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><rect x="360" y="130" width="160" height="40" fill="#fff2cc" stroke="#d6b656" pointer-events="none"/><g transform="translate(368.5,137.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="142" height="24" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 142px; white-space: nowrap; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><font style="font-size: 22px">another_folder</font></div></div></foreignObject><text x="71" y="18" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica"><font style="font-size: 22px">another_folder</font></text></switch></g><path d="M 320 50 L 320 70 L 140 70 L 140 83.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 140 88.88 L 136.5 81.88 L 140 83.63 L 143.5 81.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 320 50 L 320 70 L 440 70 L 440 123.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 440 128.88 L 436.5 121.88 L 440 123.63 L 443.5 121.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 90 210 L 90 223.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 90 228.88 L 86.5 221.88 L 90 223.63 L 93.5 221.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><rect x="30" y="170" width="120" height="40" fill="#fff2cc" stroke="#d6b656" pointer-events="none"/><g transform="translate(44.5,177.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="90" height="24" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 92px; white-space: nowrap; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><font style="font-size: 22px">subfolder</font></div></div></foreignObject><text x="45" y="18" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g><path d="M 140 130 L 140 150 L 90 150 L 90 163.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 90 168.88 L 86.5 161.88 L 90 163.63 L 93.5 161.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><rect x="160" y="170" width="120" height="40" fill="#d5e8d4" stroke="#82b366" pointer-events="none"/><g transform="translate(205.5,177.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="28" height="24" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 30px; white-space: nowrap; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><font style="font-size: 22px">file</font></div></div></foreignObject><text x="14" y="18" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g><path d="M 140 130 L 140 150 L 220 150 L 220 163.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 220 168.88 L 216.5 161.88 L 220 163.63 L 223.5 161.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><rect x="560" y="90" width="80" height="40" fill="#ffffff" stroke="#000000" pointer-events="none"/><g transform="translate(590.5,97.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="18" height="24" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 20px; white-space: nowrap; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><font style="font-size: 22px">...</font></div></div></foreignObject><text x="9" y="18" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g><path d="M 320 50 L 320 70 L 600 70 L 600 83.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><path d="M 600 88.88 L 596.5 81.88 L 600 83.63 L 603.5 81.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="none"/><rect x="360" y="190" width="160" height="40" fill="#d5e8d4" stroke="#82b366" pointer-events="none"/><g transform="translate(382.5,197.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="114" height="24" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 116px; white-space: nowrap; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><font style="font-size: 22px">another_file</font></div></div></foreignObject><text x="57" y="18" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g><rect x="50" y="230" width="80" height="40" fill="#ffffff" stroke="#000000" pointer-events="none"/><g transform="translate(80.5,237.5)"><switch><foreignObject style="overflow:visible;" pointer-events="all" width="18" height="24" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: inline-block; font-size: 12px; font-family: Helvetica; color: rgb(0, 0, 0); line-height: 1.2; vertical-align: top; width: 20px; white-space: nowrap; overflow-wrap: normal; text-align: center;"><div xmlns="http://www.w3.org/1999/xhtml" style="display:inline-block;text-align:inherit;text-decoration:inherit;"><font style="font-size: 22px">...</font></div></div></foreignObject><text x="9" y="18" fill="#000000" text-anchor="middle" font-size="12px" font-family="Helvetica">[Not supported by viewer]</text></switch></g></svg>
	\ No newline at end of file
	diff --git a/assets/sandwich.png b/assets/sandwich.png
	new file mode 100644
	index 0000000..d148872
	Binary files /dev/null and b/assets/sandwich.png differ
	diff --git a/assets/server_problem.png b/assets/server_problem.png
	new file mode 100644
	index 0000000..c754244
	Binary files /dev/null and b/assets/server_problem.png differ
	diff --git a/assets/universal_install_script.png b/assets/universal_install_script.png
	new file mode 100644
	index 0000000..15aeefd
	Binary files /dev/null and b/assets/universal_install_script.png differ
	diff --git a/css/common.css b/css/common.css
	index b912405..4c5d015 100644
	--- a/css/common.css
	+++ b/css/common.css
	@@ -1,149 +1,183 @@
	@import url(https://fonts.googleapis.com/css?family=Yanone+Kaffeesatz);
	@import url(https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic);
	@import url(https://fonts.googleapis.com/css?family=Ubuntu+Mono:400,700,400italic);

	body { font-family: 'Droid Serif'; }
	h1, h2, h3 {
	font-family: 'Yanone Kaffeesatz';
	font-weight: normal;
	}
	.remark-code, .remark-inline-code { font-family: 'Ubuntu Mono'; }

	.remark-code-line .hljs-constant { color: #5BFF68 }

	.remark-slide-content { font-size: 24px; }

	table.stack {
	border-collapse: collapse;
	table-layout: fixed;
	width: 100%;
	margin: auto;
	}

	.stack tr td:first-child {
	border: 1px black solid;
	height: 3em;
	width: 60%;
	}

	.stack .bluebg {
	background: SkyBlue
	}

	table.quiz {
	width: 100%;
	margin: auto;
	}

	.quiz td {
	border: 1px black solid;
	padding-top: 0.4em;
	padding-bottom: 0.4em;
	}

	.quiz .clicked.Y {
	background: #CCFFCC;
	}

	.quiz .clicked.N {
	background: #FFCCCC;
	}


	.two-columns table {
	table-layout: fixed;
	}

	.two-columns td {
	width: 50%;
	}

	.mnemonic {
	border: 1px solid firebrick;
	border-radius: 0.3em;
	margin-bottom: 0.5em;
	}

	.mnemonic::before {
	content: "Mnemonic:";
	margin-left: 0.25em;
	font-style: italic;
	color: firebrick;
	}

	.mnemonic p {
	margin: 0.5em;
	}

	.acronym {
	border: 1px solid #007b37;
	border-radius: 0.3em;
	margin-bottom: 0.5em;
	}

	.acronym::before {
	content: "Acronym:";
	margin-left: 0.25em;
	font-style: italic;
	color: #007b37;
	}

	.acronym p {
	margin: 0.5em;
	}

	+.advice {
	+ border: 1px solid #00027b;
	+ border-radius: 0.3em;
	+ margin-bottom: 0.5em;
	+}
	+
	+.advice::before {
	+ content: "Advice:";
	+ margin-left: 0.25em;
	+ font-style: italic;
	+ color: #00027b;
	+}
	+
	+.advice p {
	+ margin: 0.5em;
	+}
	+
	+.note {
	+ border: 1px solid #694d00;
	+ border-radius: 0.3em;
	+ margin-bottom: 0.5em;
	+}
	+
	+.note::before {
	+ content: "Note:";
	+ margin-left: 0.25em;
	+ font-style: italic;
	+ color: #694d00;
	+}
	+
	+.note p {
	+ margin: 0.5em;
	+}
	+
	.exercise {
	border: 1px solid blue;
	border-radius: 0.3em;
	margin-bottom: 0.5em;
	}

	.exercise::before {
	content: "Exercise:";
	margin-left: 0.25em;
	font-style: italic;
	color: blue;
	}

	.exercise p {
	margin: 0.5em;
	}

	.highlight {
	color: red;
	font-weight: bold;
	}

	.middle img {
	vertical-align: middle;
	}

	.small {
	font-size: smaller;
	}

	.minusmargin {
	margin-left: -10%;
	margin-right: -10%;
	}

	div.blinking {
	-webkit-animation: 1s blink step-end infinite;
	-moz-animation: 1s blink step-end infinite;
	-ms-animation: 1s blink step-end infinite;
	-o-animation: 1s blink step-end infinite;
	animation: 1s blink step-end infinite;
	display: inline-block;
	}

	@-webkit-keyframes blink {
	0% { opacity: 1.0; }
	50% { opacity: 0.0; }
	100% { opacity: 1.0; }
	}

	@keyframes blink {
	0% { opacity: 1.0; }
	50% { opacity: 0.0; }
	100% { opacity: 1.0; }
	}
	\ No newline at end of file
	diff --git a/linux_owners.html b/linux_owners.html
	new file mode 100644
	index 0000000..317e8c2
	--- /dev/null
	+++ b/linux_owners.html
	@@ -0,0 +1,1175 @@
	+<!DOCTYPE html>
	+<html>
	+ <head>
	+ <title>Linux for Owners</title>
	+ <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
	+ <link rel="stylesheet" type="text/css" href="css/common.css">
	+ </head>
	+ <body>
	+<textarea id="source">
	+
	+class: center, middle
	+
	+# Linux for Owners
	+
	+`https://goo.gl/auQmRB`
	+
	+---
	+
	+# Agenda
	+
	+1. Owning a Linux system
	+2. Course expectations
	+3. Linux landscape
	+4. Accessing `root`
	+5. Linux filesystem structure
	+6. Mounting filesystems
	+7. Working with the package manager
	+
	+
	+---
	+
	+# Owning a Linux system
	+
	+## What do we mean by that?
	+
	+--
	+
	+.highlight[Administrative privileges] vs a normal account only.
	+
	+--
	+
	+ Symptoms:
	+
	+* access to the `root` user, or
	+* access to `sudo` (or `su`) commands
	+* having installed the system yourself (optional)
	+* physical access to the machine (optional)
	+
	+--
	+
	+Having admin access usually means you are responsible for
	+.highlight[maintenance and configuration] of the system.
	+
	+For that, you need a deeper knowledge of how it works.
	+
	+---
	+
	+# Typical ownership scenarios
	+
	+--
	+
	+* Linux installed as main OS on a desktop or laptop machine
	+
	+ * Scenarios: work requirement, curiosity, alternative OS
	+ * Typically means a graphical environment
	+
	+--
	+
	+* Linux used as a virtual machine guest
	+
	+ * Scenarios: experimentation, sandbox, development
	+ * Safe way to try OSes and configurations
	+
	+--
	+
	+* Linux used as a server
	+
	+ * Can be bare-metal or virtualized
	+ * Typically means a CLI environment (over SSH)
	+
	+--
	+
	+* Linux appliance / IoT
	+
	+* Android (which you usually don't own!)
	+
	+---
	+
	+# Typical responsibilities
	+
	+--
	+
	+* Installing new software as needed
	+
	+* Configuring software and access to hardware
	+
	+* Updating software & OS
	+
	+* Securing the system and installed software
	+
	+* Solving problems as they appear
	+
	+---
	+
	+# Course expectations
	+
	+This is a crash-course limited to one day.
	+
	+* You are expected to know the basics of working with Linux.
	+ At a minimum, working with command line and editing files from it.
	+
	+* You were asked to prepare a VM with Linux, that way you can
	+ safely try admin commands and reboot the OS without affecting
	+ your main system.
	+
	+* Some commands can differ per Linux "flavour". The course sticks
	+ to Ubuntu / Debian, and may need to be adapted to other
	+ distributions.
	+
	+* The course is intended to be an introduction; to dig deeper
	+ into topics you'll need to do your own research.
	+
	+---
	+
	+# Linux landscape: What's a distribution?
	+
	+"Linux" is the name of the OS kernel, and needs a lot of other software
	+ to be a functional operating system.
	+
	+One can, in principle, assemble this collection of software themselves:
	+ such an approach is called Linux From Scratch.
	+
	+--
	+
	+It's long, requires in-depth knowledge of the system and most importantly
	+ leaves keeping the system up to date to the user.
	+
	+A better approach is to use a .highlight[distribution], which offers:
	+
	+* A curated collection of software tested to work together.
	+* A .highlight[package manager] to automate software install tasks.
	+* Pre-compiled software for faster installation.
	+* Security updates and fixes for critical bugs.
	+* Varying balance between stability and faster updates.
	+* _Optional:_ paid support.
	+
	+---
	+
	+# Linux landscape: Popular distributions
	+
	+There are many families of distributions, sharing package managers
	+ and maybe parts of the package collection.
	+--
	+
	+* Debian (package manager: `apt` / .deb packages)
	+ * Ubuntu
	+ * Kubuntu, Lubuntu, ...
	+ * Linux Mint
	+ * Kali, Tails, Devuan
	+--
	+
	+* RHEL (package manager: `yum` / .rpm packages)
	+ * Fedora
	+ * CentOS, Scientific Linux
	+ * SUSE, OpenSUSE
	+--
	+
	+* Arch Linux (package manager: `pacman`)
	+ * Manjaro Linux
	+* Gentoo (package manager: Portage / `emerge`)
	+ * Chrome OS
	+* Alpine Linux
	+* ...
	+
	+---
	+
	+# Linux landscape: Rolling / Static / LTS
	+
	+Various Linux distributions take different approaches to software updates.
	+
	+Programs update at their own pace, called "upstream".
	+
	+--
	+
	+.highlight[Rolling distributions] try to keep up with upstream version
	+ updates, with minimal changes to keep it compatible with
	+ the rest of the software stack.
	+
	+--
	+
	+.highlight[Static distributions] lock down software versions at the time
	+ of release, in order to provide more testing and stability.
	+
	+--
	+
	+However, critical bugfixes and security patches have to be ported back
	+ "downstream" to those "frozen" versions.
	+
	+Some static distributions have .highlight[Long Term Support] releases that
	+ guarantee longer availability of such patches.
	+
	+---
	+
	+# Assuming superpowers
	+
	+How do administrative powers work in Linux?
	+
	+Compared to regular users, the user with ID 0, or .highlight[`root`],
	+ is treated as .highlight[superuser]: it has the ability
	+ to bypass all usual access restrictions.
	+
	+--
	+
	+In some Linux distributions a password for `root` is set
	+ at install time and can be used to log in directly.
	+
	+However, most of the time users with administrative privileges
	+ will have access to use .highlight[`sudo` command].
	+
	+.mnemonic[
	+`sudo` stands for ".highlight[su]peruser .highlight[do]", because it executes some
	+ other command as superuser instead of current user.
	+]
	+
	+---
	+
	+# Assuming superpowers: `sudo`
	+
	+.center[
	+ ![XKCD on sudo](assets/sandwich.png)
	+]
	+
	+_Image credit:_ [XKCD #149](https://xkcd.com/149/)
	+
	+---
	+
	+# Assuming superpowers: `sudo`
	+
	+`sudo [command]` executes the command as `root` instead of the current user:
	+
	+```
	+owner@linux:~$ whoami
	+owner
	+owner@linux:~$ sudo whoami
	+[sudo] password for owner:
	+```
	+
	+--
	+
	+Normally, `sudo` asks for authentication: it requires you to supply
	+ .highlight[your own] password (not the `root` password!).
	+
	+```
	+owner@linux:~$ sudo whoami
	+[sudo] password for owner: <type in owner's password>
	+root
	+owner@linux:~$
	+```
	+
	+---
	+
	+# Assuming superpowers: `sudo`
	+
	+`sudo` remembers that you have authenticated,
	+ and subsequent commands do not require password for 15 minutes:
	+
	+```
	+owner@linux:~$ sudo whoami
	+root
	+owner@linux:~$
	+```
	+
	+--
	+
	+If you need to do a lot of stuff as root, you can use `sudo -i`
	+to start a login shell as `root`:
	+
	+```
	+owner@linux:~$ sudo -i
	+root@linux:~# whoami
	+root
	+root@linux:~#
	+```
	+
	+.mnemonic[
	+`-i` is short for .highlight[interactive]
	+]
	+
	+_Reference:_ `man sudo_root`
	+
	+---
	+
	+# To root or not to root
	+
	+Forgetting `sudo` before a command that requires it
	+ can be jarring. Therefore, there is great temptation
	+ to use a `root` shell when mostly admin tasks are involved.
	+
	+--
	+
	+Problem is, there are no "handrails" on what the `root` user can do.
	+ It's far too easy to shoot oneself in the foot.
	+
	+An error in a program run under `root` can break critical parts
	+ of the system, which won't happen under a regular user.
	+
	+--
	+
	+From a security perspective, running complex, or untrusted,
	+ programs under `root` opens you up for malicious actions as well.
	+
	+---
	+
	+# To root or not to root: a horror story
	+
	+Running this command as a `root` is a classic mean prank:
	+
	+```
	+root@linux:~# rm -rf /
	+rm: it is dangerous to operate recursively on '/'
	+rm: use --no-preserve-root to override this failsafe
	+```
	+
	+Fortunately, as written it doesn't work, there's a failsafe.
	+
	+--
	+
	+However, consider this line:
	+
	+```
	+(DO NOT RUN THIS)
	+root@linux:~# rm -rf $FOLDER/*
	+```
	+
	+This is supposed to delete everything in folder `$FOLDER`.
	+
	+But in case that variable is unset, it will happily destroy everything on the system — if run as `root`.
	+
	+---
	+
	+# To root or not to root
	+
	+In addition, if files are created while running as `root`
	+ it usually leads to them being inaccessible by normal users.
	+
	+This can lead to errors when running the same commands later
	+ as a normal user.
	+
	+--
	+
	+Most workflows are a mixture of commands that require superuser and those that don't.
	+
	+It's good practice to be aware of it and run only those parts that need it with `sudo`.
	+
	+--
	+
	+It's not a hard rule. Running a set of commands as `root` has its place,
	+ but one needs to be careful and mindful of the above nuances.
	+
	+---
	+
	+# root and SSH
	+
	+By default, even if you set a password for the `root` user,
	+ you won't be able to connect via SSH with this password.
	+
	+This is done to discourage brute-forcing the `root` password.
	+
	+--
	+
	+This encourages people to connect as their user and elevate
	+ with `sudo` if necessary. This creates more meaningful logs.
	+
	+
	+Also, if your SSH key is compromised but your user password is not,
	+ the attacker won't be able to elevate to `root` even if
	+ they can connect.
	+
	+--
	+
	+It's still possible to connect directly as `root` by weakening
	+ the security (bad idea) or adding an SSH key to the `root`
	+ account. However, previous warnings apply.
	+
	+---
	+
	+# How is `sudo` configured?
	+
	+What enables certain users to use `sudo`?
	+
	+By default, members of a specific group
	+ (e.g. `sudo`, `admin`, `wheel`)
	+ are allowed all `root` privileges after verifying their password.
	+
	+--
	+
	+There's a `/etc/sudoers` file describing the system policy.
	+
	+It can be fine-tuned to allow some users access only to
	+ specific commands, or dropping the password requirement.
	+
	+.advice[
	+ When editing `sudoers` file, always use the `visudo` script.
	+ It sanity-checks changes so that you don't lock yourself out.
	+]
	+
	+_References:_ `man sudoers`,
	+ [Understanding the sudoers file](https://medium.com/@viraj.khatavkar/understanding-the-sudoers-file-8d71961b28ac)
	+
	+---
	+
	+# Exercise: inspect the `sudoers` file
	+
	+.exercise[
	+1. Try examining the contents of `/etc/sudoers` file:
	+
	+ ```
	+ owner@linux:~$ less /etc/sudoers
	+ ```
	+
	+2. Explain the problem
	+
	+3. Fix the problem (using `sudo`)
	+]
	+
	+---
	+
	+# Bonus: violating the `sudoers` policy
	+
	+.center[ ![](assets/incident.png) ]
	+
	+_Image credit:_ [XKCD #838](https://xkcd.com/838/)
	+
	+---
	+
	+# Linux filesystem map: what goes where?
	+
	+Before we proceed, it's important to understand
	+ common filesystem locations in Linux.
	+
	+It differs a little from distribution to distribution,
	+ but generally systems adhere to the
	+ .highlight[Filesystem Hierarcy Standard], or FHS (3.0 currently).
	+
	+Not every entry in the standard will be explained, but "points of interest"
	+ will be shown.
	+
	+_References:_
	+ [Wikipedia entry on FHS](https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard),
	+ [FHS 3.0 specification](http://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.html)
	+
	+---
	+
	+# Linux filesystem: a common tree
	+
	+Under UNIX conventions, there's only a single filesystem tree visible in the system.
	+
	+There can be multiple disks, or multiple partitions on those disks, each with its
	+ own filesystem trees, but to be usable they are inserted in the common file tree
	+ as subtrees:
	+
	+.center[ ![](assets/mount.svg) ]
	+
	+---
	+
	+# Linux filesystem: a common tree
	+
	+.center[ ![](assets/mount.svg) ]
	+
	+This process is called .highlight[mounting].
	+You can examine currently mounted filesystems with the `mount` command:
	+
	+```
	+owner@linux:~$ mount
	+sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
	+proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
	+[...]
	+```
	+
	+---
	+
	+# Linux filesystem: `/home` sweet home
	+
	+As a user, you're probably familiar with .highlight[`/home`].
	+
	+Home directories for each user are usually stored there:
	+
	+```
	+owner@linux:~$ echo $HOME
	+/home/owner
	+owner@linux:~$ ls -l /home/
	+total 6
	+drwxr-xr-x 4 owner owner 4096 Jan 14 00:03 owner
	+drwxr-xr-x 2 user user 4096 Jan 15 18:31 user
	+```
	+
	+The `root` user is an exception:
	+
	+```
	+owner@linux:~$ sudo -i
	+root@linux:~# echo $HOME
	+/root
	+```
	+
	+This is done to help with troubleshooting, if `/home` is a separate filesystem
	+ and something goes wrong with it.
	+
	+---
	+
	+# Linux filesystem: configuration, _et cetera_
	+
	+We have already saw .highlight[`/etc`] mentioned
	+ when we looked at `sudoers` policy.
	+
	+In fact, by convention all .highlight[system-wide configuration] files
	+ are stored there, often grouped into folders by topic/program.
	+
	+Most files are only writable by `root`, and some highly-sensitive
	+ ones, like `/etc/sudoers`, are not readable by anyone else.
	+
	+.note[
	+ User-specific configuration (and persistent state) is usually stored
	+ in the user's home folder as hidden files/folders,
	+ e.g. `/home/owner/.bashrc`
	+
	+```
	+owner@linux:~$ ls -a ~
	+. .. .bash_history .bash_logout .bashrc .cache .gnupg .local .ssh ...
	+```
	+]
	+
	+---
	+
	+# Linux filesystem: where software lives
	+
	+Executable (.highlight["binary"]) files for software installed system-wide is read-only
	+ for regular users and is organized in (up to) 3 tiers of hierarchy of .highlight[`sbin`/`bin`] folders:
	+
	+* .highlight[`/`]`sbin`, .highlight[`/`]`bin` - essential system software
	+
	+--
	+* .highlight[`/usr/`]`sbin`, .highlight[`/usr/`]`bin` - more software that's part of the OS
	+
	+--
	+* .highlight[`/usr/local/`]`sbin`, .highlight[`/usr/local/`]`bin` - additional software
	+
	+--
	+
	+These locations can have `lib` and `include` folders
	+ for library and header files, and `share` folders
	+ for program data.
	+
	+--
	+
	+Finally, .highlight[`/opt`] provides a location for installing extra
	+ software without interfering with `/usr`.
	+
	+--
	+
	+In practice, the difference between these locations is not very well
	+ defined. Some distributions don't differentiate at all.
	+
	+---
	+
	+# Linux filesystem: not-quite-files
	+
	+Several locations on the filesystem contain virtual "files"
	+ that can be read and/or written to, but represent something else.
	+
	+--
	+
	+* .highlight[`/dev`] contains .highlight[device] files that serve
	+ as interfaces to hardware that the kernel sees and has drivers for;
	+
	+--
	+
	+* .highlight[`/proc`] contains information and interfaces to control
	+ running .highlight[processes] and some kernel systems;
	+
	+--
	+
	+* .highlight[`/sys`] contains kernel and .highlight[system] information
	+ and interfaces to control it. It's a newer method than `/proc`.
	+
	+Those locations are, again, usually read-only (or not accessible)
	+ to regular users.
	+
	+---
	+
	+# Linux filesystem: variable and temporary
	+
	+Besides fixed program data, the filesystem has locations for
	+ .highlight[variable] data, like temporary files and persistent state.
	+
	+--
	+
	+* .highlight[`/var`] represents variable data. A couple notable folders:
	+ * .highlight[`/var/log`] for system logs
	+ * .highlight[`/var/lib`] for data modified by programs, e.g. databases
	+
	+
	+--
	+
	+* .highlight[`/run`] contains state information since startup.
	+* .highlight[`/tmp`] is for temporary data, and is user-writable.
	+
	+Both `/run` and `/tmp` locations are emptied on boot, and in fact usually exist only in memory.
	+
	+--
	+
	+* .highlight[`/var/tmp`] is also for temporary data, but it survives reboot.
	+
	+---
	+
	+# Linux filesystem: other storage
	+
	+When extra storage is connected to the system, there are conventional
	+ places to add it to the filesystem.
	+
	+--
	+
	+* .highlight[`/media`] is populated with filesystems from removable storage
	+ added to the system: USB drives, CD disks, etc.
	+
	+ Often, such devices are added to `/media` automatically.
	+
	+--
	+
	+* .highlight[`/mnt`] is the traditional place to mount additional filesystems
	+ temporarily.
	+
	+---
	+
	+# Linux filesystem: where everything starts
	+
	+Last but not least, .highlight[`/boot`] contains essential files to initialize Linux
	+ when the computer starts up.
	+
	+Typical contents:
	+
	+* `/boot/grub/` contains .highlight[bootloader] components
	+* `/boot/vmlinuz*` files are compressed Linux kernels
	+* `/boot/initrd*` files are initial filesystems that are used until "real" root becomes available
	+
	+--
	+
	+.note[
	+ On some OS configurations, `/boot` is a small separate filesystem. Since it usually contains
	+ several versions of the kernel as a backup, in worst case it can run out of space.
	+
	+ In that case, you'll need to clean up older kernels before installing new versions.
	+]
	+
	+---
	+
	+# Linux filesystem: parts, assemble!
	+
	+As mentioned, the .highlight[`mount`] command can be used to list currently-mounted filesystems.
	+
	+--
	+
	+To mount a filesystem, .highlight[`mount [WHAT] [WHERE]`] format is used.
	+
	+Here, `[WHAT]` identifies where the filesystem can be accessed (e.g. a physical drive partition),
	+ and `[WHERE]` identifies the directory where its contents should be mapped.
	+
	+--
	+
	+To unmount a filesystem, .highlight[`umount [WHAT]`] (or `umount [WHERE]`) command can be used.
	+Typically, only `root` can mount or unmount.
	+
	+--
	+
	+For permanent mount rules, e.g. what gets mounted on boot, see the .highlight[`/etc/fstab`] file.
	+
	+_References:_ `man mount`, `man umount`, `man fstab`
	+
	+---
	+
	+# Exercise: adding a filesystem
	+
	+Let's see `mount` and `fstab` in action. We'll create a file that holds a small
	+ filesystem, mount it, and then set it up to mount automatically at boot.
	+
	+Let's create a 100MB file and an ext4 filesystem on it:
	+
	+```
	+owner@linux:~$ truncate -s 100m loop_file
	+owner@linux:~$ mkfs.ext4 loop_file
	+```
	+
	+Then, let's create a mount point (where the filesystem will be mapped):
	+
	+```
	+owner@linux:~$ sudo mkdir /mnt/tiny
	+owner@linux:~$ ls -la /mnt/tiny/
	+total 8
	+drwxr-xr-x 2 root root 4096 Jan 16 09:50 .
	+drwxr-xr-x 3 root root 4096 Jan 16 09:50 ..
	+```
	+
	+---
	+
	+# Exercise: mounting a filesystem
	+
	+Let's mount our tiny filesystem.
	+
	+```
	+owner@linux:~$ sudo mount /home/owner/loop_file /mnt/tiny
	+owner@linux:~$ mount \| grep tiny
	+/home/owner/loop_file on /mnt/tiny type ext4 (rw,relatime,data=ordered)
	+```
	+
	+As a regular user, we can't write to it:
	+```
	+owner@linux:~$ touch /mnt/tiny/test
	+touch: cannot touch '/mnt/tiny/test': Permission denied
	+```
	+
	+Let's make it writable:
	+```
	+owner@linux:~$ sudo chmod a+w /mnt/tiny/
	+owner@linux:~$ touch /mnt/tiny/test
	+owner@linux:~$ ls -la /mnt/tiny/
	+total 17
	+drwxrwxrwx 3 root root 1024 Jan 16 10:56 ./
	+drwxr-xr-x 3 root root 4096 Jan 16 09:50 ../
	+drwx------ 2 root root 12288 Jan 16 09:49 lost+found/
	+-rw-r--r-- 1 owner owner 0 Jan 16 10:56 test
	+```
	+
	+---
	+
	+# Exercise: unmounting a filesystem
	+
	+```
	+owner@linux:~$ ls -la /mnt/tiny/
	+total 17
	+drwxrwxrwx 3 root root 1024 Jan 16 10:56 ./
	+drwxr-xr-x 3 root root 4096 Jan 16 09:50 ../
	+drwx------ 2 root root 12288 Jan 16 09:49 lost+found/
	+-rw-r--r-- 1 owner owner 0 Jan 16 10:56 test
	+```
	+
	+Let's unmount the filesystem and examine the situation again:
	+
	+```
	+owner@linux:~$ sudo umount /mnt/tiny/
	+owner@linux:~$ ls -la /mnt/tiny/
	+total 8
	+drwxr-xr-x 2 root root 4096 Jan 16 09:50 .
	+drwxr-xr-x 3 root root 4096 Jan 16 09:50 ..
	+```
	+
	+Our file is not there.
	+
	+Note that the mount point is not writable by all,
	+ as our `chmod` command affected the tiny filesystem's root folder
	+ and not the mount point.
	+
	+---
	+
	+# Exercise: add to `fstab`
	+
	+Let's add our mount to `fstab`.
	+
	+.advice[
	+ You can edit configuration files with `sudo nano <FILENAME>` (or other editor),
	+ but it's better to use `sudoedit <FILENAME>`.
	+
	+ See [sudoedit: why use it over sudo vi?](https://superuser.com/questions/785187/sudoedit-why-use-it-over-sudo-vi) for an explanation.
	+]
	+
	+```
	+owner@linux:~$ sudoedit /etc/fstab
	+```
	+
	+It opens a file with already one or more records present.
	+We need to add one.
	+
	+---
	+
	+# Exercise: `fstab` format
	+
	+An `fstab` record contains whitespace-separated fields:
	+
	+* [file system] - where to find the filesystem
	+* [mount point] - where to map it in the system
	+* [type] - what type of filesystem it is (`-t` flag)
	+* [options] - various settings you can tweak (`-o` flag)
	+* [dump] - 0/1, setting for a very old backup solution
	+ In practice, always 0
	+* [pass] - order to check the filesystem for errors on boot
	+
	+Let's add our filesystem, at the end of the file:
	+
	+```
	+/home/owner/loop_file /mnt/tiny ext4 defaults 0 2
	+```
	+
	+Take care not to modify other entries. Save and exit.
	+
	+---
	+
	+# Exercise: filesystem in `fstab`
	+
	+Now that our example is in `fstab`, we can mount it easier:
	+
	+```
	+owner@linux:~$ sudo mount /mnt/tiny/
	+owner@linux:~$ ls /mnt/tiny
	+lost+found test
	+```
	+
	+You can mount all filesystems in `fstab` at once with `mount -a`.
	+
	+Further, our example should now be accessible after a reboot.
	+To prevent automatic mounting at boot time, use `noauto` option.
	+
	+.note[
	+ To be able to mount a filesystem, corresponding drivers/utilities need
	+ to be installed. If you fail to mount something, like a network drive,
	+ check installed packages.
	+]
	+
	+---
	+
	+# Working with the package manager
	+
	+To simplify software installation, updates and removal,
	+ distributions provide a .highlight[package manager]
	+ and a collection of "official" packages.
	+
	+Command examples for `apt`, Debian/Ubuntu package manager,
	+ will be shown, but principles apply to other managers.
	+
	+---
	+
	+# Packages: software sources
	+
	+To install software, `apt` needs up-to-date information
	+ about packages that are available.
	+
	+.highlight[`/etc/apt/sources.list`] contains the information
	+ on .highlight[repositories] to get information from for system packages.
	+
	+--
	+
	+A command needs to be run to update a local catalog
	+ of package information:
	+
	+```
	+owner@linux:~ $ sudo apt update
	+[...]
	+Get:8 http://ch.archive.ubuntu.com/ubuntu bionic-security/universe amd64 Packages [112 kB]
	+Fetched 1798 kB in 1s (1768 kB/s)
	+Reading package lists... Done
	+Building dependency tree
	+Reading state information... Done
	+12 packages can be upgraded. Run 'apt list --upgradable' to see them.
	+```
	+
	+---
	+
	+# Packages: upgrading installed packages
	+
	+Use .highlight[`apt upgrade`] command to install updates `apt` is aware of.
	+
	+--
	+
	+```
	+owner@linux:~$ apt upgrade
	+Reading package lists... Done
	+Building dependency tree
	+Reading state information... Done
	+Calculating upgrade... Done
	+The following packages will be upgraded:
	+ gjs gnome-software gnome-software-common gnome-software-plugin-snap gvfs
	+ gvfs-backends gvfs-bin gvfs-common gvfs-daemons gvfs-fuse gvfs-libs libgjs0g
	+ libsmbclient libwbclient0 linux-firmware samba-libs ubuntu-software
	+17 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
	+Need to get 71.6 MB/74.6 MB of archives.
	+After this operation, 3'258 kB of additional disk space will be used.
	+Do you want to continue? [Y/n]
	+```
	+
	+After confirmation, `apt` will download and apply updates.
	+
	+--
	+
	+.note[
	+ Sometimes, an upgrade needs to remove some (replaced) packages.
	+ In that case, `apt dist-upgrade` is used.
	+]
	+
	+---
	+
	+# Packages: to upgrade or not to upgrade?
	+
	+Static distributions like Ubuntu only update packages
	+ when serious bugfixes or security fixes are needed,
	+ with little to no functionality changes.
	+
	+As such, it's usually safe to upgrade OS-provided packages.
	+
	+--
	+
	+If you're using a rolling distribution, or a third-party
	+ repository, they can introduce breaking changes.
	+Be prepared and read available changelogs to determine when to upgrade.
	+
	+--
	+
	+If you need to stop a particular package from upgrading,
	+ you can put it on .highlight[hold]:
	+
	+```
	+owner@linux:~$ sudo apt-mark hold bash
	+bash set on hold.
	+owner@linux:~$ sudo apt-mark unhold bash
	+Canceled hold on bash.
	+```
	+
	+---
	+
	+# Packages: when to upgrade?
	+
	+For most updates, upgrades will not disrupt normal workflow
	+ and can be applied at any time.
	+
	+Note that upgrading running services (e.g. a web server)
	+ requires them to restart, briefly becoming unavailable.
	+ You may need to plan your maintenance in advance.
	+
	+--
	+
	+Some upgrades (mostly kernel updates) can't be applied without
	+ a reboot. The system will nag you about it, but you won't
	+ be forced to reboot.
	+
	+--
	+
	+General advice for any software updates: be prepared
	+ to spend some time dealing with unexpected problems.
	+
	+---
	+
	+# Packages: Finding system packages
	+
	+If you're missing some software and it's available
	+ in OS repositories, it's very easy to install.
	+
	+The shell can even .highlight[suggest the package] you're missing:
	+
	+```
	+owner@linux:~$ fortune
	+
	+Command 'fortune' not found, but can be installed with:
	+
	+sudo apt install fortune-mod
	+```
	+
	+Otherwise, you can .highlight[search known packages] by package name or description
	+ with .highlight[`apt search`]:
	+
	+```
	+owner@linux:~$ apt search cow
	+[..long list..]
	+owner@linux:~$ apt search --names-only cow
	+[..shorter list..]
	+```
	+
	+---
	+
	+# Packages: Installing system packages
	+
	+Once you know the name of the package(s), you can install them with
	+ .highlight[`apt install`]:
	+
	+```
	+owner@linux:~$ sudo apt install fortune-mod cowsay
	+Reading package lists... Done
	+Building dependency tree
	+Reading state information... Done
	+The following additional packages will be installed:
	+ fortunes-min librecode0
	+Suggested packages:
	+ filters cowsay-off fortunes
	+The following NEW packages will be installed:
	+ cowsay fortune-mod fortunes-min librecode0
	+0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
	+Need to get 638 kB of archives.
	+After this operation, 2'220 kB of additional disk space will be used.
	+Do you want to continue? [Y/n]
	+```
	+
	+After confirmation, `apt` will download and install them.
	+
	+---
	+
	+# Bonus: just what did we just install?!
	+
	+Let's test the software we just installed.
	+
	+```
	+owner@linux:~$ fortune \| cowsay
	+
	+ _____________________________________
	+/ Truth is the most valuable thing we \
	+\| have -- so let us economize it. \|
	+\| \|
	+\ -- Mark Twain /
	+ -------------------------------------
	+ \ ^__^
	+ \ (oo)\_______
	+ (__)\ )\/\
	+ \|\|----w \|
	+ \|\| \|\|
	+```
	+
	+.exercise[
	+ This could look better: we're missing some pretty colors.
	+
	+ Find the package that provides the `lolcat` application,
	+ install it and pipe the output through it.
	+]
	+
	+---
	+
	+# Packages: dependency resolution
	+
	+Let's look at that `apt install` output again.
	+
	+```
	+The following additional packages will be installed:
	+ fortunes-min librecode0
	+Suggested packages:
	+ filters cowsay-off fortunes
	+The following NEW packages will be installed:
	+ cowsay fortune-mod fortunes-min librecode0
	+0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
	+```
	+
	+Often, packages require other packages (e.g. libraries, data files)
	+ to be installed to function. The package manager's job is to find
	+ and install everything that's needed.
	+
	+.note[
	+ Rarely, a package is incompatible with already installed ones.
	+ You will then be offered to remove packages to resolve this.
	+ In that case, proceed with caution.
	+]
	+
	+---
	+
	+# Packages: getting rid of them
	+
	+If you no longer need a package, you can use .highlight[`apt remove`]:
	+
	+```
	+owner@linux:~$ sudo apt remove fortune-mod
	+Reading package lists... Done
	+Building dependency tree
	+Reading state information... Done
	+The following packages were automatically installed and are no longer required
	+ fortunes-min librecode0
	+Use 'sudo apt autoremove' to remove them.
	+The following packages will be REMOVED:
	+ fortune-mod
	+0 upgraded, 0 newly installed, 1 to remove and 12 not upgraded.
	+After this operation, 110 kB disk space will be freed.
	+Do you want to continue? [Y/n]
	+```
	+
	+After confirmation, the program will be removed,
	+ but its configuration files will remain in case you reinstall.
	+
	+--
	+
	+If you want to completely clean up the package, use .highlight[`apt purge`]:
	+
	+```
	+owner@linux:~$ sudo apt purge fortune-mod
	+```
	+
	+---
	+
	+# Packages: orphaned dependencies
	+
	+Take note of these lines in `apt remove` output:
	+
	+```
	+The following packages were automatically installed and are no longer required
	+ fortunes-min librecode0
	+```
	+
	+`apt` is informing you that `fortunes-min` and `librecode0` were installed
	+ as dependencies, but .highlight[nothing requires them anymore].
	+
	+Therefore, it's highly likely that they can be removed without affecting anything.
	+ However, `apt` does not do that automatically.
	+
	+To allow `apt` to do that, use .highlight[`apt autoremove`]:
	+
	+```
	+owner@linux:~$ sudo apt autoremove
	+[...]
	+```
	+
	+---
	+
	+# Bonus: Universal Install Script
	+
	+.center[
	+ ![:scale 50%](assets/universal_install_script.png)
	+]
	+
	+_Image credit:_ [XKCD #1654](https://xkcd.com/1654/)
	+
	+---
	+
	+class: middle, center
	+
	+# The Great TODO Gap
	+
	+\crickets\
	+
	+<!-- ############################################################################################ -->
	+
	+---
	+
	+# Where to get help?
	+
	+If you know the command, or the config file that you're trying to use, .highlight[`man`] is your friend.
	+
	+--
	+
	+Also, Google is your friend! There's no shame in learning what you don't know yet or looking up
	+ what you don't remember.
	+
	+--
	+
	+Some notable sites that are very helpful:
	+
	+* StackExchange network: https://stackoverflow.com/, https://superuser.com/, https://askubuntu.com/, https://unix.stackexchange.com/, https://serverfault.com/
	+* DigitalOcean tutorials: https://www.digitalocean.com/community/tutorials/
	+* nixCraft tutorials: https://www.cyberciti.biz/
	+
	+--
	+
	+When searching for solutions, specifying your OS version is helpful.
	+ Old advice sometimes does not apply to newer systems!
	+
	+---
	+
	+class: center
	+
	+# That's it!
	+
	+## Go forth and administrate!
	+
	+--
	+
	+..try not to break stuff, though.
	+
	+![](assets/server_problem.png)
	+Image credit: [XKCD #1084](https://xkcd.com/1084/)
	+
	+</textarea>
	+ <script src="js/vendor/remark.min.js"></script>
	+ <script src="js/vendor/jquery-3.2.1.min.js"></script>
	+ <script src="js/terminal.language.js"></script>
	+ <script src="js/common.js"></script>
	+ </body>
	+</html>
	\ No newline at end of file

No OneTemporaryActions

File Metadata

View Options

Event Timeline

No OneTemporary
Actions