Squid on OpenWrt: A UCI Validation Failure Before Startup

OpenWrt's Squid package can reject its UCI configuration before it ever starts the Squid command. A generic “validation failed” from the init script is therefore not enough reason to edit squid.conf.

Read the field-level messages preceding it and match the installed package's validation rules. For example, the startup implementation declares http_port as a port type. Trailing whitespace can fail that check while the digits look right. A failed validation result stops the callback before command registration.

For a section actually named squid, inspect the narrow value:

uci get squid.squid.http_port

Use the section name present in the installation. The package source is normally /etc/config/squid; if messages are absent, verify it exists and is readable. Another release may expose different fields.

After UCI validation, follow the native file passed to Squid. The wrapper may select an explicit file or generate one from supported inputs. Editing an unused file cannot change the generated result.

Native syntax, helpers, permissions and listener checks come later. Report either “UCI rejected http_port” or “Squid rejected the selected native configuration” with its evidence. Removing the package configuration merely to silence the first error can prevent the wrapper from doing its job.