Introduction

 

This page describes the installation and configuration of apt-cacher. It was drawn from http://www.debuntu.org/how-to-set-up-a-repository-cache-with-apt-cacher and Ubuntu Hacks by Oxer, Rankin, and Childers http://www.oreilly.com/catalog/ubuntuhks/

Added by pablodav:In Newer installations like Jaunty I recommend use this cacher instead others like apt-proxy.

Warning: Using Apt-Cacher with more than one distribution

 

Because Debian and Ubuntu have identically named (but different) .deb packages in their repositories, it is unwise to setup a single apt-cacher to be a caching package server for both Debian and Ubuntu clients at the same time. A workaround for advanced users is to run two separate instances of apt-cacher on two separate ports with two separate caches.

Server Installation

 

1. Install apt-cacher and apache2 webserver

• sudo apt-get install apt-cacher apache2

2. Enable apt-cacher

• Edit /etc/default/apt-cacher and change autostart to 1

Note: I had problems doing this on a machine with apache already installed.

Added by JT: Restart apache if you already had it installed: sudo invoke-rc.d apache2 restart

Added by pablodav: I suggest to restart apt-cacher also: sudo invoke-rc.d apt-cacher restart

Then test by going to http://server/apt-cacher to verify that it’s running.

Added by pablodav: In Jaunty use http://server:3142 instead http://server/apt-cacher (this seems to be not working anymore with /apt-cacher).

Server Configuration

 

Edit /etc/apt-cacher/apt-cacher.conf if you want to change any options. The only one I changed was admin_email.

Import any existing apt-get cache:

• sudo /usr/share/apt-cacher/apt-cacher-import.pl /var/cache/apt/archives

Added by pablodav: I strongly recommend to use -d option for symlinks, In Jaunty I had to use sudo /usr/share/apt-cacher/apt-cacher-import.pl -s /var/cache/apt/archives

Load Packages on Server from CD

 

Around upgrade time, you may find it useful to get the CD image instead of using the slow update servers, and populate your cache using that.

First, download your CD image(s) of choice (I’d recommend using bit-torrent).

Second, mount the CD image on the server running apt-cacher :

sudo mount -o loop /home/username_or_other_path/ubuntu-9.10-rc-alternate-i386.iso /media/cdrom0

 

Third, run the import on the CD image, you need the -R is needed to recurse into the CD directory structure, the -r just makes sure they are copied to the cache instead of trying to link:

sudo /usr/share/apt-cacher/apt-cacher-import.pl -R -r /media/cdrom0

 

You should see the script saying that it is importing a lot of packages.

Client Configuration Options

 

There are two ways to configure your clients to use apt-cacher. Added by pablodav: I don’t recommend to change every line with step 1. In Jaunty /apt-cache does not works. Jump to step 2 for Client Configuration.

Modify your sources.list

 

In client /etc/apt/sources.list insert apt-cacher-server/apt-cacher/ in each line, ie

• deb http://archive.ubuntu.com/ubuntu/ dapper main restricted

becomes

• deb http://apt-cacher-server/apt-cacher/archive.ubuntu.com/ubuntu/ dapper main restricted

(Warning: The apt-cacher web page advises to also add ‘:3142’ – this caused the system to fail for me)

Added by JT: on gutsy and hardy, I could not get this to work with server/apt-cacher/ but server:3142/ (NB: without the /apt-cacher/) worked fine. To clarify, use eg. deb http://apt-cacher-server:3142/archive.ubuntu.com/ubuntu/ hardy main restricted

Scientus: I think this is because apt-cacher is its own http server and this setup use apache

If it is useful, this bash script modifies client sources.list using server:3142 configuration. Copy it, paste to a file on your client system ($HOME/somefilename.sh) and remember to make it executable: chmod 744 $HOME/somefilename.sh

################################################################################
#  Name       : aptcachesources.sh
#  Version    : 1.0
#  Author     : ZComms
#
#  Copyright (c) 2010 ZComms
#
#  Released under the Creative Commons Attribution-ShareAlike 3.0 License.
#            http://creativecommons.org/licenses/by-sa/3.0/
# 
#  You are free to share and adapt the material, provided that you do so under
#  the same or similar license, and that you give credit to the original author.
#
#  The full text of the license can be found on the Creative Commons website.
#  
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#  
#  Special Notes:
#  This is one of the little 'tools' I use on my home network to make things a
#  bit easier after a new build or rebuild. I keep them on a flash drive.
#
#  The license is larger than the script - please use the URL above to get a 
#  copy for yourself. Feel free to change this for your own use, but not so free
#  to ask me to change it for you free of charge.
# 
################################################################################
# exit codes
# 0 - all is good, no errors
# 1 - general error, unspecified
# 2 - misuse of shell builtin - hardly ever used
# 3 - Bad environment variable
# 4 - Bad command line argument
# 5 - Missing file or directory
# 6 - Failed OS utility
# 255 - Dave, I can't do that.

function show_use {
    echo -en "\n\nVersion 1.0 - 2011\n"     # set version here
    echo -en "Running this script from your home directory is best\n\n"
    echo -en "Usage: aptcachesources.sh -h -v/V -t"
    echo -en "Where s=proxy server p=port f=local aptsources file\n"
    echo -en "Where -u is update to new source and -r is revert to default configuration\n\n"
    echo -en "Example:   <-u|r> -s 212.121.21.117 -p 3142 -f /etc/apt/sources.list\n\n"
}

function show_help {
    echo -en "This file allows you to set apt to use an apt proxy server. You need to specify\n"
    echo -en "your apt sources.list file, the proxy server IP/name and the proxy port number.\n"
    echo -en "It was written to ease setup for multiple systems pointing to the same proxy but\n"
    echo -en "can be used to swap out 'http://' in any file as that is all it really does.\n\n"
    echo -en "This will leave a backup file in the directory where the script resides.\n\n"
    echo -en "For more information, see man page for apt-cacher or the \n"
    echo -en "Ubuntu info: https://help.ubuntu.com/community/Apt-Cacher-Server\n"
}

START_DIR=`pwd`
NOARG=0
MODE=9
SRC_HOST="ERROR"
SRC_FILE="ERROR"
SRC_PORT="ERROR"
TEST=0

# lets figure out if the user has put enough valid arguments on the command line
if [ $# -eq $NOARG ]
then
    show_use           # explain usage
else
    while getopts ":urthHvVs:p:f:" OPT
    do
        case $OPT in 
            u ) MODE=1;;
            r ) MODE=0;;
            s ) SRC_HOST=$OPTARG;;
            p ) SRC_PORT=$OPTARG;;
            f ) SRC_FILE=$OPTARG;;
            t ) TEST=1;;
            h | H | v ) show_help
                exit 0
                ;;
            V ) cat $0 | grep 'set version here' | grep -v cat | awk '{print $4}'
                exit 0
                ;;
            * ) echo -en "\n\tERROR: Command line option not understood ($OPT)\n\n"
                show_use
                exit 4
                ;;
        esac
    done
fi

# Only two modes - make the change, or reverse it (backout)
#
if [[ $MODE = 1 ]]
then
    if [[ $TEST = 1 ]]
    then
        cat $SRC_FILE | sed -e 's%http://%http://'$SRC_HOST':'$SRC_PORT'/%' | less
        exit 0
    else    
        cat $SRC_FILE | sed -e 's%http://%http://'$SRC_HOST':'$SRC_PORT'/%' > $START_DIR/sources.new
        cp $SRC_FILE $SRC_FILE.original
        cp $START_DIR/sources.new $SRC_FILE
        if [[ -e $SRC_FILE ]]
        then
            cmp ./sources.new $SRC_FILE
            if [[ $? > 0 ]]
            then
                echo -en "\n\tThere was a problem: could not copy file $START_DIR/sources.new to $SRC_FILE"
                exit 1
            fi
            echo -en "\n\tSuccessfully modified sources.list file. See $START_DIR/sources.new\n"
            exit 0
        fi
    fi
fi

if [[ $MODE = 0 ]]
then
    if [[ $TEST = 1 ]]
    then
        cat $SRC_FILE | sed -e 's%http://'$SRC_HOST':'$SRC_PORT'/%http://%' | less
        exit 0
    else
        echo "oops"
        cat $SRC_FILE | sed -e 's%http://'$SRC_HOST':'$SRC_PORT'/%http://%' > $START_DIR/sources.nocache
        sudo cp $SRC_FILE $SRC_FILE.backout
        sudo cp $START_DIR/sources.nocache $SRC_FILE
        if [[ -e $SRC_FILE ]]
        then
            cmp $START_DIR/sources.nocache $SRC_FILE
            if [[ $? > 0 ]]
            then
                echo -en "\n\tThere was a problem: could not copy file $START_DIR/sources.nocache to $SRC_FILE"
                exit 1
            fi
            echo -en "\n\tSuccessfully modified sources.list file. See $START_DIR/sources.nocache\n"
            exit 0
        fi
    fi
fi

 

Then run

• apt-get update

Use as a proxy to APT

 

Static configuration

 

In a terminal, type:

sudo nano /etc/apt/apt.conf.d/01proxy

 

Inside your new file, add a line that says:

Acquire::http::Proxy "http://<IP address or hostname of the apt-cacher server>:3142";

 

“Roaming” mode

 

This method is useful if you are alternating between office and home with a laptop for example. It involves using the ping command to determine if the apt-cacher server is available at boot-time and then configure the APT proxy or not.

• Open /etc/rc.local (alt-F2, “gksu gedit /etc/rc.local”)
• Change the top from “#!/bin/sh -e” to “#!/bin/bash”
• put this near the end (before “exit 0” if present) replacing “SERVER_NAME_HERE” with your server’s resolvable name or it’s IP:

. /lib/lsb/init-functions
log_daemon_msg "Configuring APT cache proxy" "(based on SERVER_NAME_HERE's presence...)"
ping -c 1 SERVER_NAME_HERE &> /dev/null
if [ $? = "0" ]; then
  echo "Acquire::http::Proxy \"http://SERVER_NAME_HERE:3142\";" > /etc/apt/apt.conf.d/01SERVER_NAME_HEREproxy
else
  rm /etc/apt/apt.conf.d/01SERVER_NAME_HEREproxy &> /dev/null
fi
log_end_msg 0

 

“Roaming” mode alternative solution

 

Added by “nuaimat”:The above method didn’t work for me, so I created two sources.list versions, one named sources.list.home and other one named sources.list.work (both inside /etc/apt)I modified sources.list.home as mentioned above (Static configuration Section)then I login as root

   sudo su -

 

then created a shell script (don’t forget to replace “SERVER_NAME_HERE” with your server’s resolvable name or it’s IP ) :

. /lib/lsb/init-functions
log_daemon_msg "Configuring APT cache proxy" "(based on SERVER_NAME_HERE's presence...)"
unlink /etc/apt/sources.list

ping -c 1 SERVER_NAME_HERE &> /dev/null
if [ $? = "0" ]; then
 log_daemon_msg "found live $?"
 ln -s /etc/apt/sources.list.home /etc/apt/sources.list &> /dev/null

  for i in /etc/apt/sources.list.d/*.list; 
  do 
  local_online=`grep "SERVER_NAME_HERE" $i|wc -l`
  if [ $local_online = "0" ]; then
   sed -i 's|http://|http://SERVER_NAME_HERE/apt-cacher/|g' $i &> /dev/null
  fi;
 done;
else

 log_daemon_msg "not found"
 ln -s /etc/apt/sources.list.work /etc/apt/sources.list &> /dev/null

 for i in /etc/apt/sources.list.d/*.list; 
 do 
  sed -i 's|http://SERVER_NAME_HERE/apt-cacher/|http://|g' $i &> /dev/null
 done;
fi

log_end_msg 0

• save it as /root/check-apt-cacher
• chmod +x /root/check-apt-cacher
• crontab -e
• using your favourite editor add the following line to the crontabs

*/1 * * * * /bin/bash /root/check-apt-cacher

 

this script will run each minute (*/1) you can change it as you see fit.

“Roaming” mode event-driven solution

 

I didn’t like the idea of using cron to poll the network intermittently and the first roaming solution simply didn’t work for me, so here’s a different one I came up with.

This assumes:

• that you are running apt-cacher-ng (ACNG) and not just apt-cacher, but it should work with minor edits with a vanilla apt-cacher too
• ACNG is running both on localhost on the roaming client and in some of the networks you connect to
• apt is configured to use localhost on the roaming client
• ACNG on the roaming client is the right place to direct proxy traffic

The same if-up.d trick below could be modified to simply edit a /etc/apt/apt.conf.d/01proxy file as described in the first roaming solution.

To make it event driven I’ve used if-up.d which can run a script any time a new network interface comes online.

Create a new file /etc/network/if-up.d/apt-cacher-ng-reset-proxyand put the following script in it:

#!/bin/bash

# list of hosts that the proxy might be running on
hosts=(
        acng.on.my.home.network
        acng.on.my.work.network
        acng.at.my.friends.place
)

set_host() {
        host=$1
        line="Proxy: http://$host:3142/"
        if [[ -z $host ]]; then
                line="# Proxy: disabled because none are contactable"
        fi

        # adjust ACNG configuration to use supplied proxy
        sed -i -r "s%^\s*(#|)\s*Proxy: .*$%$line%g" \
                /etc/apt-cacher-ng/acng.conf

        # if apt-cacher-ng is running
        if service apt-cacher-ng status > /dev/null 2>&1; then
                # restart it to take hold of new config
                service apt-cacher-ng restart
        fi
        exit 0
}

try_host() {
        host=$1
        # if we can get to the supplied host
        if ping -c 1 "$host" > /dev/null 2>&1; then
                # tell ACNG to use it
                set_host "$host"
        fi
}

# Run through all possible ACNG hosts trying them one at a time
for host in "${hosts[@]}"; do
        try_host "$host"
done

# no proxies found, unset upstream proxy (i.e. we connect straight to the internet)
set_host

 

Make sure to adjust the script for your environment and make it executable with:

chmod +x /etc/network/if-up.d/apt-cacher-ng-reset-proxy

 

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CategoryPackageManagement