SQUID - Proxy server - Implementation

Base Class

The LUX5 appliance image is used as the base class for SQUID appliance.

Packages for SQUID

• audit-libs-1.3.1-1.el5.i386.rpm (LGPL)
• basesystem-8.0-5.1.1.el5.centos.noarch.rpm (public domain)
• bash-3.1-16.1.i386.rpm (GPL)
• beecrypt-4.1.2-10.1.1.i386.rpm (LGPL)
• bzip2-1.0.3-3.i386.rpm (BSD)
• bzip2-libs-1.0.3-3.i386.rpm (BSD)
• centos-release-5-0.0.el5.centos.2.i386.rpm (GPL)
• centos-release-notes-5.0.0-2.i386.rpm (GPL)
• chkconfig-1.3.30.1-1.i386.rpm (GPL)
• coreutils-5.97-12.1.el5.i386.rpm (GPL)
• cpio-2.6-20.i386.rpm (GPL)
• cracklib-2.8.9-3.1.i386.rpm (Artistic)
• cracklib-dicts-2.8.9-3.1.i386.rpm (Artistic)
• crontabs-1.10-8.noarch.rpm (Public Domain)
• cyrus-sasl-lib-2.1.22-4.i386.rpm (Freely Distributable)
• db4-4.3.29-9.fc6.i386.rpm (GPL)
• device-mapper-1.02.13-1.el5.i386.rpm (GPL)
• dhclient-3.0.5-7.el5.i386.rpm (distributable)
• diffutils-2.8.1-15.2.2.i386.rpm (GPL)
• dmidecode-2.7-1.28.2.el5.i386.rpm (GPL)
• e2fsprogs-1.39-8.el5.i386.rpm (GPL)
• e2fsprogs-libs-1.39-8.el5.i386.rpm (GPL)
• ed-0.2-38.2.2.i386.rpm (GPL)
• elfutils-libelf-0.125-3.el5.i386.rpm (GPL)
• ethtool-5-1.el5.i386.rpm (GPL)
• expat-1.95.8-8.2.1.i386.rpm (BSD)
• file-4.17-8.2.i386.rpm (distributable)
• filesystem-2.4.0-1.el5.centos.i386.rpm (Public Domain)
• findutils-4.2.27-4.1.i386.rpm (GPL)
• gawk-3.1.5-14.el5.i386.rpm (GPL)
• gdbm-1.8.0-26.2.1.i386.rpm (GPL)
• glib2-2.12.3-2.fc6.i386.rpm (LGPL)
• glibc-2.5-12.2.i386.rpm (LGPL)
• glibc-common-2.5-12.2.i386.rpm (LGPL)
• gpg-pubkey-e8562897-459f07a4.(none).rpm (pubkey)
• grep-2.5.1-54.2.el5.i386.rpm (GPL)
• gzip-1.3.5-9.el5.centos.i386.rpm (GPL)
• info-4.8-14.el5.i386.rpm (GPL)
• initscripts-8.45.14.EL-1.el5.centos.1.i386.rpm (GPL)
• iproute-2.6.18-4.el5.i386.rpm (GNU GPL)
• iputils-20020927-43.el5.i386.rpm (BSD)
• krb5-libs-1.5-23.i386.rpm (MIT, freely distributable.)
• less-394-5.el5.i386.rpm (GPL)
• libacl-2.2.39-1.1.i386.rpm (LGPL)
• libattr-2.4.32-1.1.i386.rpm (LGPL)
• libcap-1.10-26.i386.rpm (BSD-like and LGPL)
• libevent-1.1a-3.2.1.i386.rpm (BSD)
• libgcc-4.1.1-52.el5.2.i386.rpm (GPL)
• libgssapi-0.10-2.i386.rpm (GPL)
• libhugetlbfs-1.0.1-1.el5.i386.rpm (LGPL)
• libhugetlbfs-lib-1.0.1-1.el5.i386.rpm (LGPL)
• libselinux-1.33.4-2.el5.i386.rpm (Public domain (uncopyrighted))
• libselinux-python-1.33.4-2.el5.i386.rpm (Public domain (uncopyrighted))
• libsemanage-1.9.1-3.el5.i386.rpm (GPL)
• libsepol-1.15.2-1.el5.i386.rpm (GPL)
• libstdc++-4.1.1-52.el5.i386.rpm (GPL)
• libsysfs-2.0.0-6.i386.rpm (LGPL)
• libtermcap-2.0.8-46.1.i386.rpm (LGPL)
• libuser-0.54.7-2.el5.1.i386.rpm (LGPL)
• libvolume_id-095-14.5.el5.i386.rpm (GPL)
• lm_sensors-2.10.7-4.el5.i386.rpm (GPL)
• logrotate-3.7.4-8.i386.rpm (GPL)
• m2crypto-0.16-6.el5.1.i386.rpm (BSDish)
• MAKEDEV-3.23-1.2.i386.rpm (GPL)
• mcstrans-0.1.10-1.el5.i386.rpm (GPL)
• mingetty-1.07-5.2.2.i386.rpm (GPL)
• mktemp-1.5-23.2.2.i386.rpm (BSD)
• module-init-tools-3.3-0.pre3.1.16.el5.i386.rpm (GPL)
• ncurses-5.5-24.20060715.i386.rpm (distributable)
• net-snmp-5.3.1-24.el5_2.2.i386.rpm (BSDish)
• net-snmp-libs-5.3.1-24.el5_2.2.i386.rpm (BSDish)
• net-snmp-utils-5.3.1-24.el5_2.2.i386.rpm (BSDish)
• net-tools-1.60-73.i386.rpm (GPL)
• newt-0.52.2-9.i386.rpm (LGPL)
• nfs-utils-1.0.9-24.el5.i386.rpm (GPL)
• nfs-utils-lib-1.0.8-7.2.z2.i386.rpm (GPL)
• openldap-2.3.27-5.i386.rpm (OpenLDAP? )
• openssh-4.3p2-16.el5.i386.rpm (BSD)
• openssh-clients-4.3p2-16.el5.i386.rpm (BSD)
• openssh-server-4.3p2-16.el5.i386.rpm (BSD)
• openssl-0.9.8b-8.3.el5.i686.rpm (BSDish)
• pam-0.99.6.2-3.14.el5.i386.rpm (GPL or BSD)
• passwd-0.73-1.i386.rpm (BSD)
• patch-2.5.4-29.2.2.i386.rpm (GPL)
• pcre-6.6-1.1.i386.rpm (BSD)
• perl-5.8.8-10.i386.rpm (Artistic or GPL)
• popt-1.10.2-37.el5.i386.rpm (GPL)
• portmap-4.0-65.2.2.1.i386.rpm (BSD)
• procps-3.2.7-8.1.el5.i386.rpm (GPL)
• psmisc-22.2-5.i386.rpm (BSD/GPL)
• python-2.4.3-19.el5.i386.rpm (PSF - see LICENSE)
• python-elementtree-1.2.6-5.i386.rpm (PSF)
• python-sqlite-1.1.7-1.2.1.i386.rpm (GPL)
• python-urlgrabber-3.1.0-2.noarch.rpm (LGPL)
• readline-5.1-1.1.i386.rpm (GPL)
• rpm-4.4.2-37.el5.i386.rpm (GPL)
• rpm-libs-4.4.2-37.el5.i386.rpm (GPL)
• rpm-python-4.4.2-37.el5.i386.rpm (GPL)
• samba-client-3.0.28-0.el5.8.i386.rpm (GNU GPL Version 2)
• samba-common-3.0.28-0.el5.8.i386.rpm (GNU GPL Version 2)
• sed-4.1.5-5.fc6.i386.rpm (GPL)
• setup-2.5.58-1.el5.noarch.rpm (public domain)
• shadow-utils-4.0.17-12.el5.i386.rpm (BSD)
• slang-2.0.6-4.el5.i386.rpm (GPL)
• sqlite-3.3.6-2.i386.rpm (Public Domain)
• sysfsutils-2.0.0-6.i386.rpm (GPL)
• sysklogd-1.4.1-39.2.i386.rpm (GPL)
• SysVinit? -2.86-14.i386.rpm (GPL)
• tar-1.15.1-23.el5.i386.rpm (GPL)
• tcpdump-3.9.4-11.el5.i386.rpm (BSD)
• tcp_wrappers-7.6-40.2.1.i386.rpm (Distributable)
• termcap-5.5-1.20060701.1.noarch.rpm (Public Domain)
• tmpwatch-2.9.7-1.1.el5.1.i386.rpm (GPL)
• tzdata-2006m-2.fc6.noarch.rpm (GPL)
• udev-095-14.5.el5.i386.rpm (GPL)
• usermode-1.88-3.el5.i386.rpm (GPL)
• util-linux-2.13-0.44.el5.i386.rpm (distributable)
• vim-minimal-7.0.109-3.i386.rpm (freeware)
• vixie-cron-4.1-66.1.el5.i386.rpm (distributable)
• wget-1.10.2-7.el5.i386.rpm (GPL)
• which-2.16-7.i386.rpm (GPL)
• xen-ukrnl-3.2.2-17.i386.rpm (GPL)
• xen-umods-3.2.2-17.i386.rpm (GPL)
• yum-3.0.5-1.el5.centos.2.noarch.rpm (GPL)
• zlib-1.2.3-3.i386.rpm (BSD)

Class Volumes

SQUID itself is not sensitive to the volume configuration and will work on most any setup. Besides the squid application, it does not require any additional software to be able to start. Samba client is required for logging. The setup chosen for the 1.0 release is as follows: - boot volume, 150MB size, mounted as "/", writeable, instantiable. - usr volume, 180MB size, mounted as "/usr", read-only, common The boot volume contains a basic Linux installation as the one present on the LUX5 appliance.

In summary, SQUID's boot volume contains:

• CentOS 5, as base OS image (as installed on the LUX5 appliance)
• squid version 3.0.STABLE13
• Samba client, for accessing files through the log terminal
• sshd, used for logging into the component through the default interface

Add-on packages for SQUID

• Main
  • squid.tgz: precompiled squid 3.0.STABLE13

• Dependencies - Samba Client (used for the logs)
  • samba-common-3.0.28-0.el5.8.i386.rpm: samba shared libraries
  • samba-client-3.0.28-0.el5.8.i386.rpm: samba client
  • net-snmp-5.3.1-24.el5_2.2.i386.rpm: Net-SNMP
  • net-snmp-libs-5.3.1-24.el5_2.2.i386.rpm: Net-SNMP libraries
  • net-snmp-utils-5.3.1-24.el5_2.2.i386.rpm: Net-SNMP utilities
  • dmidecode-2.7-1.28.2.el5.i386.rpm: reports information about your system's hardware as described in

• • lm_sensors-2.10.7-4.el5.i386.rpm: health monitoring support for Linux

Contents of the release directory for SQUID:

Exported appliance image:

• squid-24-1.0.0.tar.bz2

SQUID automated build script: use this to automatically build SQUID appliance

• squid-build.24.1.0.0.tar.bz2

SQUID automated test suite: use this to test SQUID appliance

• usquid-test.24.1.0.0.tar.bz2

Source RPMs:

• squid-3.0.STABLE13.tar.gz - squid packed source
• samba-3.0.28-0.el5.8.src.rpm - Samba source rpm

Theory of Operation

SQUID acts as an agent, accepting HTTP requests from clients and passes them to the appropriate server. It stores a copy of the returned data in an on-disk cache. When the same data is requested multiple times, since a copy of the on-disk data is returned to the client, speeding up access and decreasing origin server load.

Configuration

General

squid is configured by using a file called squid.conf . This file is created dynamically at start of appliance according to SQUID properties supplied by AppLogic24? . This is done at boot-time by appliance.sh script.

Log Files

Access Log

Appliance Implementation Details

The SQUID appliance contains the following files in the /appliance folder on its boot volume. These files are used to implement the appliance:

Important Notes

None.

-- AndriyMayevskyy - 19 Feb 2009