Squid on Ubuntu 24.04 LTS

Squid is a mature, widely deployed caching proxy for HTTP and HTTPS. It sits between clients and the wider web, caching frequently requested content to cut bandwidth and latency, and applying access control over which clients may reach which destinations. This cloudimg image runs Squid 6.14 on Ubuntu 24.04 LTS, configured as a responsible, secure by default caching proxy for outbound web gateways, bandwidth saving caches and controlled egress in private networks.

Security is built in as a non open proxy. An open forward proxy that will relay requests for anyone on the internet is abused for spam relaying, anonymisation and attack laundering, so this image ships with source address ACLs: the proxy answers only the machine itself and hosts on private RFC1918 ranges, and every other source, including the public internet, falls through to a final deny all rule and is refused. There is deliberately no allow all rule. Requests to non web ports and CONNECT tunnels to non TLS ports are blocked, the cache manager is reachable only from the machine itself, ICP is disabled, and version string, Via and forwarded for headers are hardened.

The image ships without proxy authentication: access is controlled by source address, not a shared password, so there is no bootstrap credential to leak. If you want password based access you can opt in to Basic authentication and generate your own credential on the VM, never baked into the image. A shipped self test tool proves the proxy forwards, serves a repeat from cache as a cache hit, and refuses a denied request.

Squid is distributed under the GNU General Public License version 2, free and open source with no per CPU or per deployment fee. cloudimg is not affiliated with or endorsed by the Squid project or the Squid Software Foundation. cloudimg provides packaging, secure by default hardening, security patching, and 24/7 support with a guaranteed 24 hour response SLA.