Adding and Updating Packages

You use the Advanced Packaging Tool (apt) to manage additional applications (in the form of packages) and to install the latest updates.

Before running any apt-get commands or after changing the /etc/apt/sources.list file, you need to run apt-get update.

Updating the Package Cache

To work properly, APT relies on a local cache of the available packages. You must populate the cache initially, and then periodically update it with apt-get update:

cumulus@switch:~$ sudo -E apt-get update
Get:1 http://repo3.cumulusnetworks.com CumulusLinux-3 InRelease [7,624 B]
Get:2 http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates InRelease [7,555 B]
Get:3 http://repo3.cumulusnetworks.com CumulusLinux-3-updates InRelease [7,660 B]
Get:4 http://repo3.cumulusnetworks.com CumulusLinux-3/cumulus Sources [20 B]
Get:5 http://repo3.cumulusnetworks.com CumulusLinux-3/upstream Sources [20 B]
Get:6 http://repo3.cumulusnetworks.com CumulusLinux-3/cumulus amd64 Packages [38.4 kB]
Get:7 http://repo3.cumulusnetworks.com CumulusLinux-3/upstream amd64 Packages [445 kB]
Get:8 http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates/cumulus Sources [20 B]
Get:9 http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates/upstream Sources [11.8 kB]
Get:10 http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates/cumulus amd64 Packages [20 B]
Get:11 http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates/upstream amd64 Packages [8,941 B]
Get:12 http://repo3.cumulusnetworks.com CumulusLinux-3-updates/cumulus Sources [20 B]
Get:13 http://repo3.cumulusnetworks.com CumulusLinux-3-updates/upstream Sources [776 B]
Get:14 http://repo3.cumulusnetworks.com CumulusLinux-3-updates/cumulus amd64 Packages [38.4 kB]
Get:15 http://repo3.cumulusnetworks.com CumulusLinux-3-updates/upstream amd64 Packages [444 kB]
Ign http://repo3.cumulusnetworks.com CumulusLinux-3/cumulus Translation-en_US
Ign http://repo3.cumulusnetworks.com CumulusLinux-3/cumulus Translation-en
Ign http://repo3.cumulusnetworks.com CumulusLinux-3/upstream Translation-en_US
Ign http://repo3.cumulusnetworks.com CumulusLinux-3/upstream Translation-en
Ign http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates/cumulus Translation-en_US
Ign http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates/cumulus Translation-en
Ign http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates/upstream Translation-en_US
Ign http://repo3.cumulusnetworks.com CumulusLinux-3-security-updates/upstream Translation-en
Ign http://repo3.cumulusnetworks.com CumulusLinux-3-updates/cumulus Translation-en_US
Ign http://repo3.cumulusnetworks.com CumulusLinux-3-updates/cumulus Translation-en
Ign http://repo3.cumulusnetworks.com CumulusLinux-3-updates/upstream Translation-en_US
Ign http://repo3.cumulusnetworks.com CumulusLinux-3-updates/upstream Translation-en
Fetched 1,011 kB in 1s (797 kB/s)
Reading package lists... Done

Listing Available Packages

After the cache is populated, use the apt-cache command to search the cache to find the packages in which you are interested or to get information about an available package. Here are examples of the search and show sub-commands:

cumulus@switch:~$ apt-cache search tcp
socat - multipurpose relay for bidirectional data transfer
fakeroot - tool for simulating superuser privileges
tcpdump - command-line network traffic analyzer
openssh-server - secure shell (SSH) server, for secure access from remote machines
openssh-sftp-server - secure shell (SSH) sftp server module, for SFTP access from remote machines
python-dpkt - Python packet creation / parsing module
libfakeroot - tool for simulating superuser privileges - shared libraries
openssh-client - secure shell (SSH) client, for secure access to remote machines
rsyslog - reliable system and kernel logging daemon
libwrap0 - Wietse Venema's TCP wrappers library
netbase - Basic TCP/IP networking system

cumulus@switch:~$ apt-cache show tcpdump
Package: tcpdump
Status: install ok installed
Priority: optional
Section: net
Installed-Size: 1092
Maintainer: Romain Francoise <rfrancoise@debian.org>
Architecture: amd64
Multi-Arch: foreign
Version: 4.6.2-5+deb8u1
Depends: libc6 (>= 2.14), libpcap0.8 (>= 1.5.1), libssl1.0.0 (>= 1.0.0)
Description: command-line network traffic analyzer
 This program allows you to dump the traffic on a network. tcpdump
 is able to examine IPv4, ICMPv4, IPv6, ICMPv6, UDP, TCP, SNMP, AFS
 BGP, RIP, PIM, DVMRP, IGMP, SMB, OSPF, NFS and many other packet
 types.
 .
 It can be used to print out the headers of packets on a network
 interface, filter packets that match a certain expression. You can
 use this tool to track down network problems, to detect attacks
 or to monitor network activities.
Description-md5: f01841bfda357d116d7ff7b7a47e8782
Homepage: http://www.tcpdump.org/
cumulus@switch:~$

Adding a Package

To add a new package, first ensure the package is not already installed on the system:

cumulus@switch:~$ dpkg -l | grep {name of package}

If the package is installed already, ensure it is the version you need. If the package is an older version, update the package from the Cumulus Linux repository:

cumulus@switch:~$ sudo -E apt-get upgrade

If the package is not already on the system, add it by running apt-get install. This retrieves the package from the Cumulus Linux repository and installs it on your system together with any other packages on which this package might depend.

For example, the following adds the package tcpreplay to the system:

cumulus@switch:~$ sudo -E apt-get install tcpreplay
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
tcpreplay
0 upgraded, 1 newly installed, 0 to remove and 1 not upgraded.
Need to get 436 kB of archives.
After this operation, 1008 kB of additional disk space will be used.
Get:1 https://repo.cumulusnetworks.com/ CumulusLinux-1.5/main tcpreplay amd64 4.6.2-5+deb8u1 [436 kB]
Fetched 436 kB in 0s (1501 kB/s)
Selecting previously unselected package tcpreplay.
(Reading database ... 15930 files and directories currently installed.)
Unpacking tcpreplay (from .../tcpreplay_4.6.2-5+deb8u1_amd64.deb) ...
Processing triggers for man-db ...
Setting up tcpreplay (4.6.2-5+deb8u1) ...
cumulus@switch:~$ 

Listing Installed Packages

The APT cache contains information about all the packages available on the repository. To see which packages are actually installed on your system, use dpkg. The following example lists all the package names on the system that contain tcp:

cumulus@switch:~$ dpkg -l \*tcp\*
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                          Version             Architecture        Description
+++-=============================-===================-===================-===============================================================
un  tcpd                          <none>              <none>              (no description available)
ii  tcpdump                       4.6.2-5+deb8u1      amd64               command-line network traffic analyzer
cumulus@switch:~$

Upgrading to Newer Versions of Installed Packages

Upgrading a Single Package

You can upgrade a single package by running apt-get install. Perform an update first so that the APT cache is populated with the latest package information.

To see if a package needs to be upgraded, run the apt-cache show <pkgname> command to show the latest version number of the package. Use dpkg -l <pkgname> to show the version number of the installed package.

Upgrading All Packages

You can update all packages on the system by running apt-get update, then apt-get upgrade. This upgrades all installed versions with their latest versions but does not install any new packages.

Adding Packages from Another Repository

As shipped, Cumulus Linux searches the Cumulus Linux repository for available packages. You can add additional repositories to search by adding them to the list of sources that apt-get consults. See man sources.list for more information.

If you want to install packages that are not in the Cumulus Linux repository, the procedure is the same as above, but with one additional step.

Installing packages outside of the Cumulus Linux repository requires the use of apt-get; however, depending on the package, you can use easy-install and other commands.

To install a new package, complete the following steps:

1. Run the dpkg command to ensure that the package is not already installed on the system:

   cumulus@switch:~$ dpkg -l | grep {name of package}
   

2. If the package is installed already, ensure it is the version you need. If it is an older version, update the package from the Cumulus Linux repository:

   cumulus@switch:~$ sudo -E apt-get update
   cumulus@switch:~$ sudo -E apt-get install {name of package}
   cumulus@switch:~$ sudo -E apt-get upgrade
   

3. If the package is not on the system, the package source location is most likely not in the /etc/apt/sources.list file. If the source for the new package is not in sources.list, edit and add the appropriate source to the file. For example, add the following if you want a package from the Debian repository that is not in the Cumulus Linux repository:

   deb http://http.us.debian.org/debian jessie main
   deb http://security.debian.org/ jessie/updates main
   

   Otherwise, the repository might be listed in /etc/apt/sources.list but is commented out, as can be the case with the early-access repository:

   #deb http://repo3.cumulusnetworks.com/repo CumulusLinux-3-early-access cumulus
   

   To uncomment the repository, remove the # at the start of the line, then save the file:

   deb http://repo3.cumulusnetworks.com/repo CumulusLinux-3-early-access cumulus
   

4. Run apt-get update then install the package and upgrade:

   **Network Disruptions When Updating/Upgrading**
   
   The `apt-get upgrade` and `apt-get install` commands cause
   disruptions to network services:
   
     - The `apt-get upgrade` command might result in services being
       restarted or stopped as part of the upgrade process.
   
     - The `apt-get install` command might disrupt core services by
       changing core service dependency packages.
   
   In some cases, installing new packages with `apt-get install` might
   also upgrade additional existing packages due to dependencies. To
   review potential issues before installing, run `apt-get install
   --dry-run`.
   

   cumulus@switch:~$ sudo -E apt-get update
   cumulus@switch:~$ sudo -E apt-get install {name of package}
   cumulus@switch:~$ sudo -E apt-get upgrade
   

Cumulus Supplemental Repository

Cumulus Networks provides a Supplemental Repository that contains third party applications commonly installed on switches.

The repository is provided for convenience only. You can download and use these applications; however, the applications in this repository are not tested, developed, certified, or supported by Cumulus Networks.

Below is a non-exhaustive list of some of the packages present in the repository:

• htop lets you view CPU, memory, and process information.
• scamper is an ECMP traceroute utility.
• mtr is an ECMP traceroute utility.
• dhcpdump is similar to TCPdump but focused only on DHCP traffic.
• vim is a text editor.
• fping provides a list of targets through textfile to check reachability.
• scapy is a custom packet generator for testing.
• bwm-ng is a real-time bandwidth monitor.
• iftop is a real-time traffic monitor.
• tshark is a CLI version of wireshark.
• nmap is a network scanning utility.
• minicom is a USB/Serial console utility that turns your switch into a terminal server (useful for out of band management switches to provide a console on the dataplane switches in the rack).
• apt-cacher-ng caches packages for mirroring purposes.
• iptraf is a ncurses-based traffic visualization utility.
• swatch monitors system activity. It reads a configuration file that contains patterns for which to search and actions to perform when each pattern is found.
• dos2unix converts line endings from Windows to Unix.
• fail2ban monitors log files (such as /var/log/auth.log and /var/log/apache/access.log) and temporarily or persistently bans the login of failure-prone IP addresses by updating existing firewall rules. This utility is not hardware accelerated on a Cumulus Linux switch, so only affects the control plane.

To enable the Supplemental Repository:

1. In a file editor, open the /etc/apt/sources.list file.

   cumulus@leaf01:~$ sudo nano /etc/apt/sources.list
   

2. Uncomment the following lines:

   #deb http://repo3.cumulusnetworks.com/repo Jessie-supplemental upstream
   #deb-src http://repo3.cumulusnetworks.com/repo Jessie-supplemental upstream
   

3. Update the list of software packages:

   cumulus@leaf01:~$ sudo apt-get update -y
   

4. Install the software in which you are interested:

   cumulus@leaf01:~$ sudo apt-get install htop
   

Related Information

• Debian GNU/Linux FAQ, Ch 8 Package management tools
• man pages for apt-get, dpkg, sources.list, apt_preferences