How to self compile Squid v7 to work with ICAP on Ubuntu Linux 22.04?

According to the MetaDefender ICAP Server documentation, integrating Squid with ICAP using versions 5.5 through 6.11 may result in a known bug that affects the user experience during file downloads via the RESPMOD request. This issue has been resolved in Squid version 7 and later, and currently Squid doesn’t have a pre-compiled installation package for this version.

1. Installing prerequisite packages to compile

sudo apt install build-essential autoconf automake make libtool pkg-config libssl-dev libcppunit-dev libkrb5-dev libsasl2-dev libxml2-dev libcap-dev g++ perl

From Squid 6, you will need any compiler that is C++17-compiliant. These should be available on latest unix and linux distributions. (Read more at Squid Official Guide).

2. Download latest Squid v7 release

squid : Optimising Web Delivery

After downloading the archive, extract the contents of the tar file and navigate into the extracted directory.

tar xvf squid-7.0.0-2024xxxx-xxxx.tar

cd squid-7.0.0-VCS/

Configure Squid options

./configure   \

--prefix=/usr   \

--localstatedir=/var   \

--libexecdir=/usr/lib/squid   \

--datadir=/usr/share/squid   \

--sysconfdir=/etc/squid   \

--with-default-user=proxy   \

--with-logdir=/var/log/squid   \

--with-pidfile=/var/run/squid.pid   \

--enable-ssl   \

--enable-security-file-certgen   \

--enable-icap-client   \

--enable-http-violations \

--with-openssl \

--enable-linux-netfilter

Explanation of Key Options

• --prefix, --localstatedir, --sysconfdir: Define installation paths for Squid binaries, configuration files, logs, and runtime data.
• --with-default-user=proxy: Runs Squid under the proxy user for better security isolation.
• --enable-icap-client: Enables ICAP protocol support for content adaptation.
• --enable-ssl, --with-openssl: Adds SSL/TLS support, required for HTTPS and ICAPS.
• --enable-security-file-certgen: Enables on-the-fly certificate generation for SSL bumping.
• --enable-http-violations: Allows flexibility in HTTP protocol behavior, useful for advanced proxy configurations.
• --enable-linux-netfilter: Enables Netfilter (iptables) integration for transparent proxying.

Output Paths

Once configured and built with the options above:

• Configuration files will be located at: /etc/squid/squid.conf
• Log files will be available at: /var/log/squid

3. Compile & Install Squid

To compile Squid, run the below command:

make

After the compilation has finished, run the below command to install Squid into your system:

sudo make install

4. Verify Squid installation

You can verify Squid has been installed successfully by using squid -v command