Package Management

Is controlling software (Packages) in a Linux environment.

RPM / YUM / DNF present on:

• Redhat
• CentOS
• Fedora
• Suse

apt-get / dpkg present on:

• Debian
• Ubuntu
• Mint

Redhat Package Manager – now recursive – RPM Package Manager – after being adopted by multiple distros.

Package file naming conventions (NOT A REQUIREMENT):

• packagename-a.b.c-x.arch.rpm
  • Package Name - name of package, like.. samba
  • Version Number - (a.b.c) this is the package version number like 3.6.5 – the programmer assigns this number.
  • Build Number - number following version number (x) represents minor changes (patches, tweaks) made by package container.
  • Architecture - Defines the architecture the package was made to run on. i386 is common. there are further archs like: i586, i686, x86_64, PPC, noarch(scripts)

Operators:

• -i – Install
• -U – Upgrade if already installed
• -q – Query, get info about packages

uses apt-get / dpkg

Config file located in /etc/apt/sources.list important. sources.list.d folder contains official repos.

• apt-get update – updates repo list. DOES NOT UPGRADE.

• search thing – searches packages on local package cache for thing to download from server.
• stats – shows stats based on the metadata downloaded about our repos.
• depends apache2 – shows dependencies for the apache2 package.
• unmet – shows pkgs that have unmet depends.

• apt-get install apache2 - install apache2 + deps from repos.
• apt-get upgrade – upgrades out of date packages.
• apt-get clean – cleans up local pkg files, temp files, etc.
• apt-get autoclean – only cleans out packages that are no longer avail in our source repo. These can no longer be downloaded and are largely useless files.
• apt-get install -s php5 – -s says simulate install php5. useful!
• apt-get install -y php5 – will auto input YES on prompts.
• apt-get install -y -q php5 – -q omits some terminal output.
• apt-get source php5 – this will download the source files php5 and not the PACKAGE php5.
• apt-get dist-upgrade – RTFM, performs upgrade but also handles changing of dependencies of new versions of a package. As a result, some packages may be removed.

You can edit sources in /etc/apt/sources.list

deb     http://http.debian.net/debian wheezy         main
deb-src http://http.debian.net/debian wheezy         main
deb     http://security.debian.org/   wheezy/updates main
deb-src http://security.debian.org/   wheezy/updates main

deb entries specify debian PACKAGES where as deb-src specifies SOURCE PACKAGES, upon which to compile a package/program.

Useful commands:

• apt-get update

• Uses yum/rpm.
• Repos listed in /etc/yum.repos.d/

• -ivh packagefile - Installs packagefile with a series of hashes as indicators.
• -uvh - Same as -ive but upgrades a a package if already installed?
• -q pkgname - Queries to see if packagename is installed.
• -e pkgname - remove pkgname from system.

• yum makecache fast - updates local cache of repo contents. Similar to Pacman -Syy
• yum search name - searches repos for pkgs named name
• yum install httpd - installs httpd and deps from repos.
• yum update – updates all packages on system.